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Japheth

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Germany (South),
24.10.2022, 10:56
 

WDe and GPT, booting DOS (Users)

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Hello,

recently I added support for GPT to WDe ( no binary available yet ).

I tried to boot MS-DOS 7.1 from a GPT-partitioned disk ( via GRUB ), but that failed. Elaborating the problem one can "see" that the boot sector(s) of the FAT32 partition run correctly, IO.SYS is found and some sectors of it are loaded at the correct address, but after IO.SYS has taken over, the boot process stops.

Is there a known solution to this little problem?

And - does FreeDOS or DR-DOS behave better?




P.S: Please don't ask why I would want to do such things!

---
MS-DOS forever!
tom

Homepage

Germany (West),
24.10.2022, 17:31

@ Japheth
 

WDe and GPT, booting DOS

Post reply

> Hello,
>
> recently I added support for GPT to WDe ( no binary available yet ).
>
> I tried to boot MS-DOS 7.1 from a GPT-partitioned disk ( via GRUB ), but
> that failed. Elaborating the problem one can "see" that the boot sector(s)
> of the FAT32 partition run correctly, IO.SYS is found and some sectors of
> it are loaded at the correct address, but after IO.SYS has taken over, the
> boot process stops.
>
> Is there a known solution to this little problem?


boot from floppy.

at least FreeDOS will tolerate a GPT disk even if it can't detect a FAT partition on this disk (yet).
Japheth

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Germany (South),
25.10.2022, 05:24

@ tom
 

WDe and GPT, booting DOS

Post reply

> boot from floppy.

That's not a "solution" but a capitulation, total defeat ... :-D

Actually, I found out what MS-DOS 7.1 does during boot and could implement a (boot sector) hack that makes it boot from the GPT partition. Runs quite stable so far ( ScanDisk finds nothing to complain ).

However, just the boot partition is detected and used ... to detect further FAT partitions ( including the "EFI system partition" ) would need more.

---
MS-DOS forever!
tom

Homepage

Germany (West),
25.10.2022, 13:40

@ Japheth
 

WDe and GPT, booting DOS

Post reply

> > boot from floppy.
>
> That's not a "solution" but a capitulation, total defeat ... :-D
>
> Actually, I found out what MS-DOS 7.1 does during boot and could implement
> a (boot sector) hack that makes it boot from the GPT partition. Runs quite
> stable so far ( ScanDisk finds nothing to complain ).
how did you do this?

did you re-invent "Hybrid GPT" by writing a MBR into the boot sector?


>
> However, just the boot partition is detected and used ... to detect further
> FAT partitions ( including the "EFI system partition" ) would need more.
Japheth

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Germany (South),
25.10.2022, 17:29

@ tom
 

WDe and GPT, booting DOS

Post reply

> how did you do this?
>
> did you re-invent "Hybrid GPT" by writing a MBR into the boot sector?
No. I added some code to the FAT32 bootsector ( sector#2 ) to intercept Int 0x13
and return a fake FAT32 PT entry if sector 0 of HD 0x80 is read.

Also, in config.sys the very first device driver is one that restores the old Int 0x13 vector ( by using good old "virus call" int 2Fh, ah=13h :-D ).

---
MS-DOS forever!
Zyzzle

27.10.2022, 16:08

@ Japheth
 

WDe and GPT, booting DOS

Post reply

> > how did you do this?
> >
> > did you re-invent "Hybrid GPT" by writing a MBR into the boot sector?
>
> No. I added some code to the FAT32 bootsector ( sector#2 ) to intercept Int
> 0x13
> and return a fake FAT32 PT entry if sector 0 of HD 0x80 is read.
>
> Also, in config.sys the very first device driver is one that restores the
> old Int 0x13 vector ( by using good old "virus call" int 2Fh, ah=13h :-D ).
Are you willing to do a public release of this "hack"? It would be very useful to many of us who want to boot DOS on GPT partitions. I think limit on such GPT paritions recognized by DOS 7.1 will still be hard-limit of 2048 GiB, correct?
Japheth

Homepage

Germany (South),
27.10.2022, 16:41

@ Zyzzle
 

WDe and GPT, booting DOS

Post reply

> Are you willing to do a public release of this "hack"? It would be very
> useful to many of us who want to boot DOS on GPT partitions. I think limit
> on such GPT paritions recognized by DOS 7.1 will still be hard-limit of
> 2048 GiB, correct?
The problem with making such low-level stuff public is that it's only useful for people who know exactly what they are doing. If interested, I can send you a copy via PM.

The code is an assembly program, size 3-sectors ( containing the FAT boot sector, the "file system info" sector and the "second" boot sector ). But you cannot just write it to the HD, you have to adjust the BPB at offset 11 in the first boot sector ( fields "hidden sectors", "size", "sectors/fat" ... ).

And yes, partition size is - of course - limited to 2 TB. Worse, the partition has to be located in the first 2 TB of the HD ( this could be "fixed", but requires a "permanently" modified int 13h handler, something I wanted to avoid [ besides the fact that I simply don't own a HD with size > 2 TB ] ).

---
MS-DOS forever!
Japheth

Homepage

Germany (South),
28.10.2022, 20:13

@ Japheth
 

WDe and GPT, booting DOS

Post reply

> The problem with making such low-level stuff public is that it's only
> useful for people who know exactly what they are doing. If interested, I
> can send you a copy via PM.
No need for PMs, I uploaded the source - with a little "how to" :-D

https://github.com/Baron-von-Riedesel/DOS71BSG

---
MS-DOS forever!
Zyzzle

29.10.2022, 02:39

@ Japheth
 

WDe and GPT, booting DOS

Post reply

> > The problem with making such low-level stuff public is that it's only
> > useful for people who know exactly what they are doing. If interested, I
> > can send you a copy via PM.
>
> No need for PMs, I uploaded the source - with a little "how to" :-D
>
> https://github.com/Baron-von-Riedesel/DOS71BSG
Thanks, got it compiled and working as a test on a GPT'd (primary) partition. Seems to work well.
Richard

02.11.2022, 03:39

@ Japheth
 

WDe and GPT, booting DOS

Post reply

> > The problem with making such low-level stuff public is that it's only
> > useful for people who know exactly what they are doing. If interested, I
> > can send you a copy via PM.
>
> No need for PMs, I uploaded the source - with a little "how to" :-D
>
> https://github.com/Baron-von-Riedesel/DOS71BSG


I have (finally) set-up a broken (but still usable for testing) laptop that had Windows 10 but replaced the hard drive with a 300 GB hard drive and formatted to FAT32.

I installed FreeDOS T2211 build to C:\ (300 GB) and my USB install stick is now D:\


Using WDE in FreeDOS I have saved the first 3 sectors of the MBR to a file (called 3sectors).

As I am running FreeDOS (not DOS71) there is no DOS71BSG.BIN - is it possible to proceed further (with FreeDOS), and if so, how?
Zyzzle

02.11.2022, 06:43

@ Richard
 

WDe and GPT, booting DOS

Post reply

> > > The problem with making such low-level stuff public is that it's only
> > > useful for people who know exactly what they are doing. If interested,
> I
> > > can send you a copy via PM.
> As I am running FreeDOS (not DOS71) there is no DOS71BSG.BIN - is it
> possible to proceed further (with FreeDOS), and if so, how?
 You must compile the source posted above with JWASM compiler. Also, If you want to only run FAT32, you'll not need DOS71BSG.BIN, which will be created from the compiled source's binary .COM file.

DOS7!BSG is only useful if you're running DOS 7.1 and want to boot from a primary GPT partition. You're going to overwrite your bootsector with the binary data in DOS71BSG, which allows GPT paritions to be booted in DOS 7.1. But, that's not all. You need to also modify the offsets, as described in the README on the github source code site, in order to get it working. It's an advanced tool / hack, and as far as I know doesn't and isn't intended to work with FreeDOS.
Japheth

Homepage

Germany (South),
02.11.2022, 07:55

@ Richard
 

WDe and GPT, booting DOS

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> Using WDE in FreeDOS I have saved the first 3 sectors of the MBR to a file
> (called 3sectors).
First you should make yourself familiar with the difference of MBR ( the boot sector of the DISK ) and a FAT32 "boot sector".

Some details where FD may differ from MS-DOS:

- the MS-DOS kernel is named IO.SYS.
- the boot code of DOS71BSG.BIN loads IO.SYS at 0070:0000
- the boot code loads just the first 4 sectors of IO.SYS.
- the boot code checks four bytes of loaded IO.SYS ( at pos 0 and pos 200h )
- the boot code loads SI:DI with the start cluster of IO.SYS
- the boot code of MS-DOS jumps to 0070:0200 to switch control to the kernel
- when jumping, there are a few values on the stack that IO.SYS might use.

So there's pretty much that may go wrong when using DOS71BSG for FreeDOS...:-D

---
MS-DOS forever!
ecm

Homepage E-mail

Düsseldorf, Germany,
02.11.2022, 09:55

@ Japheth
 

WDe and GPT, booting DOS

Post reply

> First you should make yourself familiar with the difference of MBR ( the
> boot sector of the DISK ) and a FAT32 "boot sector".
>
> Some details where FD may differ from MS-DOS:
>
> - the MS-DOS kernel is named IO.SYS.
> - the boot code of DOS71BSG.BIN loads IO.SYS at 0070:0000
> - the boot code loads just the first 4 sectors of IO.SYS.
> - the boot code checks four bytes of loaded IO.SYS ( at pos 0 and pos 200h
> )
> - the boot code loads SI:DI with the start cluster of IO.SYS
> - the boot code of MS-DOS jumps to 0070:0200 to switch control to the
> kernel
> - when jumping, there are a few values on the stack that IO.SYS might use.
>
> So there's pretty much that may go wrong when using DOS71BSG for
> FreeDOS...:-D
I made it so my FAT32 and FAT16 and FAT12 boot sector loaders can load various kernels using different protocols. Build options select which protocol to implement. You can look at the protocols supported here for FAT12/FAT16: https://hg.pushbx.org/ecm/ldosboot/file/094041a616f5/boot.asm#l140 and for FAT32 here: https://hg.pushbx.org/ecm/ldosboot/file/094041a616f5/boot32.asm#l110

Largely the same information is encoded in the load settings for the lDebug BOOT commands at https://hg.pushbx.org/ecm/ldebug/file/b98dc45862ba/source/msg.asm#l1899 (This is used by a single build of a loader that implements different protocols at run time.)

In short, for the FreeDOS kernel:

* Default name is KERNEL.SYS

* Load address is linear 00600h

* Entrypoint is at CS:IP = 60h:0

* BL holds load unit for int 13h

* Full file must be loaded, implying that the boot sector loader needs to relocate itself away from linear 07C00h

* SS:BP points to the boot sector with (E)BPB (not used by current kernels)

---
l
ecm

Homepage E-mail

Düsseldorf, Germany,
02.11.2022, 11:21

@ ecm
 

WDe and GPT, booting DOS

Post reply

> Largely the same information is encoded in the load settings for the lDebug
> BOOT commands at
> https://hg.pushbx.org/ecm/ldebug/file/b98dc45862ba/source/msg.asm#l1899
> (This is used by a single build of a loader that implements different
> protocols at run time.)
Quoting the MS-DOS v7 load protocol settings from this:

  istruc LOADSETTINGS
at lsKernelName,        dw msg.msdos7_kernel_name
at lsAddName,           dw msg.addname_empty
at lsMinPara,           dw 40h
at lsMaxPara,           dw 80h
at lsOptions,           dw LOAD_SET_DL_UNIT | LOAD_SET_SIDI_CLUSTER \
                         | LOAD_DATASTART_HIDDEN | LOAD_PUSH_DPT \
                         | LOAD_LBA_SET_TYPE | LOAD_MESSAGE_TABLE
at lsSegment,           dw 70h
at lsEntry,             dd 200h
at lsBPB,               dw 7C00h, -1
at lsCheckOffset,       dw 200h
at lsCheckValue,        db "BJ"
at lsName,              asciz "MSDOS7"
        iend

> > - the MS-DOS kernel is named IO.SYS.
Indeed the kernel name is IO.SYS

> > - the boot code of DOS71BSG.BIN loads IO.SYS at 0070:0000
Load address is linear 00700h (segment 70h)

> > - the boot code loads just the first 4 sectors of IO.SYS.
Technically the next loader at the start of IO.SYS expects that you load 2 KiB of it, regardless the sector size

> > - the boot code checks four bytes of loaded IO.SYS ( at pos 0 and pos
> 200h
> > )
The word at position 0 has the "MZ" signature, the word at position 200h a "BJ" signature

> > - the boot code loads SI:DI with the start cluster of IO.SYS
This appears to be only DI for FAT12/FAT16 file systems, though it is SI:DI for FAT32

> > - the boot code of MS-DOS jumps to 0070:0200 to switch control to the
> > kernel
Entrypoint is at 70h:200h, which will execute the "BJ" signature, which happens to be harmless: inc dx then dec dx. Visible at https://hg.pushbx.org/ecm/ldosboot/file/094041a616f5/iniload.asm#l796

> > - when jumping, there are a few values on the stack that IO.SYS might
> use.
The dword [SS:SP] holds the address of the IVT entry of interrupt 1Eh, that is the value 0:78h.

The dword [SS:SP + 4] holds the original contents of the int 1Eh vector

The dword [SS:BP - 4], while close to the stack, I wouldn't say it is "on the stack" exactly. Anyway, it holds the 32-bit sector number of the data of the first cluster in the FS (datastart). This includes the hidden sectors for the MS-DOS v6 and v7 load protocols, ie it is a value in the int 13h unit, not in the FS image.

The boot sector, much like for the FreeDOS load protocol, is stored at SS:BP. The MS-DOS initial loader actually uses its (E)BPB to load the remainder of its kernel.

Another part that is hardly "on the stack" is the message table. It is used in case of errors to display during the initial loader's operation. It is documented somewhat in https://hg.pushbx.org/ecm/ldebug/file/b98dc45862ba/source/msg.asm#l1860 and https://hg.pushbx.org/ecm/ldebug/file/b98dc45862ba/source/boot.asm#l2486 (The message table is the only part that my boot sector loaders do not provide even if MS-DOS v7 load protocol compatibility is enabled.)

Besides, DL passes the load int 13h unit and the third byte of the boot sector passed indicates whether to use the LBA extensions of int 13h to load from the load unit. It has to be a partition table type byte, where the values for FAT16 LBA and FAT32 LBA indicate to the initial loader to use LBA extensions.

---
l
Japheth

Homepage

Germany (South),
04.11.2022, 08:06

@ ecm
 

WDe and GPT, booting DOS

Post reply

> * Full file must be loaded, implying that the boot sector loader needs to
> relocate itself away from linear 07C00h
Interesting! So I assume - for FAT12/16 - it has to follow the FAT chain for a full read of kernel.sys. And does this code - including the relocation stuff - still fit in one sector ( as the boot loader of the MS-DOS 6.2 kernel, for example ) ?

---
MS-DOS forever!
ecm

Homepage E-mail

Düsseldorf, Germany,
04.11.2022, 10:14

@ Japheth
 

WDe and GPT, booting DOS

Post reply

> > * Full file must be loaded, implying that the boot sector loader needs
> to
> > relocate itself away from linear 07C00h
>
> Interesting! So I assume - for FAT12/16 - it has to follow the FAT chain
> for a full read of kernel.sys. And does this code - including the
> relocation stuff - still fit in one sector ( as the boot loader of the
> MS-DOS 6.2 kernel, for example ) ?
Yes, it is necessary to follow the FAT chain to read the full file. (Though it would be required for the MS-DOS v6/v7 load protocols as well if the first 1536/2048 bytes of IO.SYS happen to be fragmented.)

You can read the source for the current boot sector loader in https://github.com/FDOS/kernel/blob/bb1bbbb1cb74525bb943725fc83027f634e4eae7/boot/boot.asm

It does fit in one sector, it does LBA or CHS reads, it is 8086-clean. However, it comes in two builds, either for FAT12 or FAT16, not both. It relocates itself to 1FE0h:7C00h (linear 27A00h), without checking that there is that much memory available. This position (plus the position of some more buffers above linear 1FE00h) also limits the maximum kernel size to "134k", according to the memory map comment at the top. Because the loader reads full clusters it also limits the maximum cluster size.

The loaders read in the whole FAT (should be maximum 6 KiB for FAT12, maximum 128 KiB for FAT16) then create a cluster list for the entire kernel. This means that the FAT buffer can be discarded as soon as the cluster list is complete. Then the list is used to read the kernel file data.

Their boot32.asm is a FAT32 boot sector loader: https://github.com/FDOS/kernel/blob/bb1bbbb1cb74525bb943725fc83027f634e4eae7/boot/boot32.asm It also appears to be 8086-clean. It is CHS only. It does fit in a single sector, too. Unlike the FAT12/FAT16 loader it does not build a cluster list. It instead buffers a single FAT sector and uses shared routines to walk the FAT for loading the root directory and the kernel.

The boot32lb.asm is here: https://github.com/FDOS/kernel/blob/bb1bbbb1cb74525bb943725fc83027f634e4eae7/boot/boot32lb.asm It is similar to the boot32.asm except it is LBA-only and uses 386-level instructions. It also fits in a single sector.

I can add some comments about my boot.asm and boot32.asm (in ldosboot repo) later.

---
l
ecm

Homepage E-mail

Düsseldorf, Germany,
04.11.2022, 11:30

@ ecm
 

WDe and GPT, booting DOS

Post reply

> Yes, it is necessary to follow the FAT chain to read the full file. (Though
> it would be required for the MS-DOS v6/v7 load protocols as well if the
> first 1536/2048 bytes of IO.SYS happen to be fragmented.)
>
> You can read the source for the current boot sector loader in
> https://github.com/FDOS/kernel/blob/bb1bbbb1cb74525bb943725fc83027f634e4eae7/boot/boot.asm
>
> It does fit in one sector, it does LBA or CHS reads, it is 8086-clean.
> However, it comes in two builds, either for FAT12 or FAT16, not both. It
> relocates itself to 1FE0h:7C00h (linear 27A00h), without checking that
> there is that much memory available. This position (plus the position of
> some more buffers above linear 1FE00h) also limits the maximum kernel size
> to "134k", according to the memory map comment at the top. Because the
> loader reads full clusters it also limits the maximum cluster size.
>
> The loaders read in the whole FAT (should be maximum 6 KiB for FAT12,
> maximum 128 KiB for FAT16) then create a cluster list for the entire
> kernel. This means that the FAT buffer can be discarded as soon as the
> cluster list is complete. Then the list is used to read the kernel file
> data.
>
> Their boot32.asm is a FAT32 boot sector loader:
> https://github.com/FDOS/kernel/blob/bb1bbbb1cb74525bb943725fc83027f634e4eae7/boot/boot32.asm
> It also appears to be 8086-clean. It is CHS only. It does fit in a single
> sector, too. Unlike the FAT12/FAT16 loader it does not build a cluster
> list. It instead buffers a single FAT sector and uses shared routines to
> walk the FAT for loading the root directory and the kernel.
>
> The boot32lb.asm is here:
> https://github.com/FDOS/kernel/blob/bb1bbbb1cb74525bb943725fc83027f634e4eae7/boot/boot32lb.asm
> It is similar to the boot32.asm except it is LBA-only and uses 386-level
> instructions. It also fits in a single sector.
>
> I can add some comments about my boot.asm and boot32.asm (in ldosboot repo)
> later.
My loaders for FAT12/FAT16 also fit in a single sector. Like FreeDOS, my boot.asm can be built either for FAT12 or FAT16. My FAT16 and FAT32 loaders both buffer one FAT sector at a time. The FAT12 FAT is loaded in its entirety (cut off after 6 KiB even if the FAT size is specified as larger than that). The FAT buffers are kept around while loading the FAT12/FAT16 file and the FAT32 root directory and kernel file.

Unlike FreeDOS's and MS-DOS's load protocol, my native lDOS protocol allows to pass the information on what part of the FAT is loaded to the kernel, which can re-use that data. Unlike FreeDOS's loaders, my loaders check for a variety of error conditions like a too long file and/or cluster size. The relocation done by my loaders, if enabled, uses a target calculated from the amount of memory available.

With the native lDOS protocol my sector loaders all support loading from LBA and falling back to CHS, querying CHS geometry and falling back to what's hardcoded in the BPB, using partition information passed by the MBR loader, and loading fragmented files from any root directory entry. (Some of these features need to be disabled at build time to fit other load protocols into the sector for FAT12/FAT16.) They are also all 8086-clean.

Unlike Microsoft's original loaders, my loaders will use the FAT even when the MS-DOS v6 or v7 load protocol is used, enabling these files to be fragmented. The only case where the FAT is not used is when building boot.asm (FAT12/FAT16) with non-FAT access, which requires the cluster size to be as large as or larger than the part that needs to be loaded. This is checked at run time.

My FAT32 boot sector loader is split into two stages. The second stage, called FSIBOOT, is stored in a previously unused part of the FSINFO sector. (If the sector size is at least 1024 Bytes then FSIBOOT is stored in the boot sector.) Although the first stage and the FSIBOOT stage are highly dependent on one another, the interface for any single version of FSIBOOT is well-defined. The load protocol specific bits are limited to the first stage, so multiple first stages for different protocols can use the same FSIBOOT if they're built for the same FSIBOOT version. (Eg for use with Metakern.)

My IBMDOS and MS-DOS v6 load protocols support finding the directory entries for the BIO and DOS file in any root directory entries, copying them to the expected positions at linear 00500h and 00520h. This is true of the IBMDOS load protocol support of the FAT32 loader, too. (PC-DOS 7.10 uses this protocol to boot off of a FAT32 FS.)

My loaders are available in https://hg.pushbx.org/ecm/ldosboot/file/094041a616f5/

---
l
Richard

03.01.2023, 16:37

@ ecm
 

WDe and GPT, booting DOS

Post reply

> > ... many many things mentioned ...


It is not immediately clear to me if you have successfully booted FreeDOS
from a GPT partition.


I have unsuccessfully tried to set up bootable FreeDOS on a
FAT32 64 MB GPT partition. Grub 2.02 (via Linux Mint 19) adds FreeDOS
to the boot menu - but it does not boot FreeDOS (yet).


I am assuming Japheth's method for MS-DOS 7.1 on GPT could be reconfigured
for FreeDOS on GPT (I hope that this can be achieved).


Any pointers, etc you can offer would be greatly appreciated. It would
take me a long time to fully understand all you have mentioned on this topic.


Below is what I have so far done.







Using Japheth's code in full, annotated (added some comments and "line numbers",
e.g., o123 to indicate line 123 of Japheth's original code ("o" for original))




fd_bs_00.asm
https://www.dropbox.com/s/n15804fh297nngz/fd_bs_00.asm?dl=1
should produce exactly Japheth's DOS71BSG.bin (i.e., no code changes, just comments etc)


fd_bs_01.asm
https://www.dropbox.com/s/czlh5mw06plsmpq/FD_bs_01.asm?dl=1
is first round of changes to attempt FreeDOS on GPT


FDmrei13.bat
https://www.dropbox.com/s/somc7vcko61qsj8/FDmrei13.bat?dl=1
is the .bat file to generate require i13 supplementary code


FDresI13.asm
https://www.dropbox.com/s/8605mgxpwukul0t/FDresI13.asm?dl=1
is the modified code written by Japheth


FDresI13.sys
https://www.dropbox.com/s/scgvzicj11pnnou/FDRESI13.SYS?dl=1
is the (modified) supplementary .sys file for CONFIG.SYS


RestI13.asm
https://www.dropbox.com/s/owld47spyvfqa1b/RestI13.asm?dl=1
is Japheth's original code


RestI13.sys
https://www.dropbox.com/s/pcqhci50vuvpcz0/RESTI13.SYS?dl=1
is the original (unmodified) .sys file for CONFIG.SYS







Summary of my changes (shown in bold) is below


{ relates to comments by ecm

o123 relates to line 123 in Japheth's o(riginal) code
r123 relates to my annotation for line o123





FD_bs_01.asm


;r001-:
;r001__: 2023aJAN02
;r001_: FD_bs_01.asm --> Fdos_bs.asm
;r001_a:
;r001_b: compiling FD.bat
;r001_c: @echo off
;r001_d: rem make FAT32 FreeDOS boot sector for GPT
;r001_e: jwasm -bin -nologo -F1=FD01_bsg.lst -Fo=FD01_bsg.bin -DMAKEGPTBS FD_bs_01.asm
;r001a:
;r001b: MS-DOS 7.1 kernel is IO.sys
;r001c: {FreeDOS kernel is KERNEL.sys}
;r001d:
;r001e: the boot code of DOS71bsg.bin loads IO.sys at 0070:0000
;r001f: {Fdos_bsg.bin} KERNEL.sys at 0060:0000 (linear 00600h)
;r001g:
;r001h: the boot code loads the first 4 sectors of IO.sys
;r001i:
;r001j:
;r001k: the boot code checks four bytes of loaded IO.sys (at pos 0 and pos 200h)
;r001l:
;r001m:
;r001n: the boot code loads SI:DI with the start cluster of IO.sys
;r001o:
;r001p:
;r001q: the boot code of MS-DOS jumps to 0070:0200 to switch control to the kernel
;r001r: {Entrypoint is at CS:IP = 60h:0}
;r001s:
;r001t: when jumping, there are a few values on the stack that IO.sys might use
;r001u:
;r001v:
;r001w:
;r001x: {BL holds load unit for int 13h}
;r001y: {full file must be loaded,implying that the boot sector loader needs
;r001z: {to locate itself away from linear 07C00h}
;r001zz: {SS:BP points to the boot sector with (E)BPB
;r001_: { (not used by current kernels)
;o001:
;o002: ;*** boot sector(s) FAT32, DOS 7.1
;o003:
;o004: ;--- 1. boot sector is read at 0000:7C00h
;o005: ;--- 2. sector 0 is read at 0000:0700h
;r005: ;--- 2. sector 0 is read at 0000:0600h
;o006: ;--- 3. 2 more sectors (fs info, bs2) are read at 0000:7E00
;o007: ;--- jmp to 8000h ( bs2 )
;o008: ;--- 4. directory sectors are read to 0000:0700h until IO.SYS is found
;r009: ;--- 4. directory sectors are read to 0000:0600h until KERNEL.SYS is found
;o009: ;--- FAT with read to get next cluster at 0000:7E00h
;o010: ;--- 5. first 4 sectors of IO.SYS are read at 0000:0700h
;r010: ;--- 5. first 4 sectors of KERNEL.SYS are read at 0000:0600h
;o011: ;--- jmp to IO.SYS 0070:0200h
;r011: ;--- jmp to KERNEL.SYS 0060:0200h
;r011z: [/b]





;r026:
PTOFS equ 1BEh ;o027: offset partition table in MBR
SIZEPTE equ 16 ;o028: size partition table entry
;o029:
BSADDR equ 7C00h ;o030: address where boot sectors (3) are loaded
MBRADDR equ 0700h ;o031:address where MBR is loaded
ROOTADDR equ 0700h ;o032: address where root directory sectors are loaded
FATADDR equ 7E00h ;o033: address where FAT sectors are loaded
; IOSYSADDR equ 0700h ;o034: address where IO.SYS sectors are loaded
KERNELsysADDR equ 0600h ;r034: address wheren KERNEL.SYS sectors are loaded
;r034: [/b]





;r180:
o180_L7CF6:
o181: jnc o188_error1 ; "ungueltiges system"
;r181: ; "invalid system"
o182: jmp o207_error2 ; "e/a fehler"
;r182: ; "e/a error"
o183_bs_ok:
o184: cmp [bp].BSECT.version, 0 ; [bp+2Ah]
o185: ja o188_error1 ; "ungueltiges system"
;r185: ; "invalid system"
;o186: jmp o316_readiosys ; jmp to 2. boot sector ( to load first 4 sectors of IO.SYS )
r186: jmp r316_readKERNELsys ; jmp to 2. boot sector ( to load first 4 sectors of KERNEL.sys)
o187:
o188_error1:
o189: mov si, offset L7D7E ; "ungueltiges system"
;r189: ; "invalid system"
o190_emsgexit: ; <--- display err msg SI
;r190:[/b]




;r205:
o205: mov si, offset L7D81 ; "Datentraeger wechseln und Taste druecken"
;r205z: ; "Change data medium and press button"
o206: jmp o190_emsgexit ;--->
o207_error2:
o208: mov si, offset L7D7F ; "E/A-Fehler" "E/A-Error"
o209: jmp o190_emsgexit ;--->
o210_L7D26:
;r210:





;r273:
L7D7E db offset msg1 - ($+1) ; offset to "Ungueltiges System" ;o274: "Invalid System"
L7D7F db offset msg2 - ($+1) ; offset to "E/A-Fehler" ;o275: "E/A-Error"
L7D80 db offset msg1 - ($+1) ; offset to "Ungueltiges System" ;o276: "Invalid System"
L7D81 db offset msg3 - ($+1) ; offset to "Datentraeger wechseln..." ;o277: "Change data medium..."
; msg1 db 0Dh, 0Ah, "Ungueltiges System ", -1 ;o278:
msg1 db 0Dh, 0Ah, "Invalid System ", -1 ;r278:
; msg2 db 0Dh, 0Ah, "E/A-Fehler ", -1 ;o279:
msg2 db 0Dh, 0Ah, "E/A-Error ", -1 ;r279:
; msg3 db 0Dh, 0Ah, "Datentraeger wechseln und Taste druecken", 0Dh, 0Ah, 0 ;o280:
msg3 db 0Dh, 0Ah, "Change data medium and press button ", 0Dh, 0Ah, 0 ;r280:
db 0, 0 ;o281: not used
; namekrnl db "IO SYS" ;o282: [b]
namekrnl db "KERNEL SYS" ;r282:
db "MSDOS SYS" ;o283: not used
o284:
dw offset L7D7E - offset o091_start ;o285:
db 0 ;o286: not used
o287:
db "WINBOOT SYS" ;o288: not used
dw 0 ;o289: not used
o290:
o291: org BSADDR+1FEh
dw 0AA55h ;o292:
;r292: [/b]




;r316: ;
; o316_readiosys proc ;
r316_readKERNELsys proc ;

o317: CLI
o318: MOVZX EAX, [bp].BSECT.num_fats ; [BP+10h]
o319: MOV ECX, [bp].BSECT.sectors_fat32 ; [BP+24h]
o320: MUL ECX
o321: ADD EAX, [bp].BSECT.hidden_sectors ; [BP+1Ch]
o322: MOVZX EDX, [bp].BSECT.reserved_sectors; [BP+0Eh]
o323: ADD EAX, EDX
o324: XOR CX, CX
o325: MOV [bp].BSECT.dwStartData, EAX ; start of data region
o326: MOV [bp].BSECT.dwFatSecNo, -1 ; no FAT sector read yet
o327: CLI
o328: MOV EAX, [bp].BSECT.root_startcl ; [BP+2Ch]
o329: CMP EAX, 2
o330: JB o188_error1
o331: CMP EAX, 0FFFFFF8h
o332: JAE o188_error1
o333: SHLD EDX, EAX, 16
o334: STI
o335_nextcluster: ; <--- next cluster
o336: PUSH DX
o337: PUSH AX
o338: CLI
o339: SHL EAX, 16 ; "shl eax,16"+"shrd eax,edx,16" = 9 bytes
o340: SHRD EAX, EDX, 16 ; "mov eax, [bp-20]" = 4 bytes!
o341: SUB EAX, 2
o342: MOVZX EBX, [bp].BSECT.sectors_cluster ; [BP+0Dh]
o343: MOV SI, BX
o344: MUL EBX ; eax=rel. sector# of cluster
o345: ADD EAX, [bp].BSECT.dwStartData ; eax=abs. sector# of cluster
o346: SHLD EDX, EAX, 16 ; dx:ax=abs. sector#
o347: STI
;r348:
o348_nextdirsect: ; <--- read next directory sector
o349: MOV BX, ROOTADDR
o350: MOV DI, BX
o351: MOV CX, 1
o352: CALL o226_read_sectors ; read 1 directory sector ( sets BX = BX+200h! )
o353: JB o207_error2 ; "e/a fehler" "e/a error"
o354_nextdirentry: ; <--- next dir entry
o355: CMP [DI], CH ; end of directory?
o356: JZ o374_done_root
o357: MOV CL, 8+3
o358: PUSH SI
o359: MOV SI, offset namekrnl ; "IO SYS"
;r359: ; "KERNEL SYS"
o360: REPE CMPSB
o361: POP SI
o362: JZ o377_found
;r362:





;r394: ;
o395: STI
;o396: MOV BX, IOSYSADDR ;
r396: MOV BX, KERNELsysADDR ;
o397: PUSH BX
;o398: MOV CX, 4 ;read 4 sectors of IO.SYS at 0070:0000
r398: MOV CX, 4 ;read 4 sectors of KERNEL.SYS at 0060:0000
o399: CALL o226_read_sectors
o400: POP BX
o401: JB o207_error2 ; "e/a fehler" "e/a error"
o402: CMP WORD PTR [BX], 5A4Dh;check "MZ"
o403: JNZ o406_invalid
o404: CMP WORD PTR [BX+0200h], 4A42h ; this is "BJ", actually "inc dx", "dec dx"
;o405: JZ o409_iosys_ok ;
r405: JZ r409_KERNELsys_ok ;
o406_invalid:
o407: MOV SI, offset L7D80 ;"ungueltiges system" "invalid system"
o408: JMP o190_emsgexit ;error
;o409_iosys_ok: ;
r409_KERNELsys_ok: ;
if ?ICINT13 ;o410:
o411: call o488_installi13
endif ;o412:
o413: ; JMP 0070h:0200h
db 0eah ;o414:
; dw 0200h, 0070h ;o415: jump to loaded part of IO.SYS, registers BP, SP, SI, DI must be correct!
dw 0200h, 0060h ;r415: jump to loaded part of KERNEL.SYS, registers BP, SP, SI, DI must be correct!
o416:
; o316_readiosys endp ;o417:
r316_readKERNELsys endp ;
;r417:






;r472: ;
o473: MOV BX, DI
o474: MOV CX, 1
o475: CALL o226_read_sectors
o476: POP DX
o477: JB o207_error2 ; "e/a fehler" "e/a error"
o478_done:
o479: STI
o480: MOV BX, DX ; BX=offset within FAT sector for current entry
o481: RET
o442_readfatsec endp ;o482:
;r482: [/b]






FD.bat

@echo off
rem make FAT32 FreeDOS boot sectors for MBR and GPT
jwasm -bin -nologo -Fl=FD_bsm.lst -Fo=FD_bsm.bin FD_bs_01.asm
jwasm -bin -nologo -Fl=FD_bsg.lst -Fo=FD_bsg.bin -DMAKEGPTBS FD_bs_01.asm





FDresi13.asm (originally Resti13.asm)

.code ;o032:
;o033:
dw 0ffffh ;o034:
dw 0ffffh ;o035:
dw 8000h ;attribute ;o036:
dw offset devstrat ;device strategy ;o037:
dw offset devint ;device interrupt ;o038:
; db 'RESTI13$' ;device name ;o039:
db 'FDresi13$' ;r039:

; invoke printf, CStr("resti13: old=%X:%X, new=%X:%X",10), cx, bx, ax, dx ;o093:
invoke printf, CStr("FDresi13: old=%X:%X, new=%X:%X",10), cx, bx, ax, dx ;r093:







FDmrei13.bat (originally Mresti13.bat)

@echo off
jwasm -bin -nologo -Fl -Fo=FDRESI13.SYS FDresI13.asm







fdconfig.sys (added the following as 1st line)

device=c:\FDresi13.sys

also tried
device = c:\resti13.sys

but both changes here for fdconfig.sys does not make FreeDOS bootable
on GPT (FAT32 64 MB partition) for my changes to date.




Below are relevant WDE screenshots of the GPT FAT32 64 MB FreeDOS partition




[image]


[image]


[image]


[image]


[image]
ecm

Homepage E-mail

Düsseldorf, Germany,
04.01.2023, 13:42

@ Richard
 

WDe and GPT, booting DOS

Post reply

> > > ... many many things mentioned ...
>
>
>
> It is not immediately clear to me if you have successfully booted FreeDOS
> from a GPT partition.
I have booted the FreeDOS kernel using my loaders (ldosboot boot sector loaders or bootable lDebug loader command) from a FAT12, FAT16, or FAT32 partition on a diskette (unpartitioned) or MBR-partitioned. I have no interest at this time to load from a GPT-partitioned unit.

> I am assuming Japheth's method for MS-DOS 7.1 on GPT could be reconfigured
> for FreeDOS on GPT (I hope that this can be achieved).
This is certainly possible. However, you will need to understand the involved memory layout and load protocols quite well to adapt this.


> Any pointers, etc you can offer would be greatly appreciated. It would
> take me a long time to fully understand all you have mentioned on this
> topic.
You're still "reading 4 sectors of KERNEL.SYS". This is wrong, you need to load the entire KERNEL.SYS file. And as mentioned you have to relocate your loader to make space for the kernel, which you did not do at all yet. And you should use the FAT to follow the chain of the kernel file, not assume that its data is contiguous (unfragmented). (The loader you're working on does have a "get next cluster" function for walking the FAT32 root directory's chain, already. That can be used to walk the chain of a file, too.)

Further, you're still checking for the "MZ" and "BJ" signatures of the kernel file. These signatures are generally not found in the FreeDOS kernel file (unless it is a multi-format file like my kernels/debuggers), so checking for them is wrong here.

Also, you changed the "db 0EAh" far immediate jump to jump to 60h:200h. This is wrong, as I already wrote the entrypoint is at 60h:0.

SI:DI need not be set for loading a FreeDOS kernel format file, though they do not harm anything either. Your comments on them are wrong however.


I did not check the device driver (CONFIG.SYS) component of this yet. However, the above errors are certainly present in the pre-kernel stage.

---
l
ecm

Homepage E-mail

Düsseldorf, Germany,
04.01.2023, 14:11

@ ecm
 

Booting FreeDOS from an MS-DOS v7 compatible IO.SYS

Post reply

I figured you may be interested in using my boot stages to create a FreeDOS kernel file that can be loaded as a compatible replacement for IO.SYS for MS-DOS v7. (Or, MS-DOS v6 IO.SYS as well, in fact.)

The following log is as run on a machine with a recent Mercurial (hg), wget, Info-Zip unzip, and nasm installed. The quote marks for string defines are written in the way that bash expects them. (That is, use both double and single quotes so as to pass one pair of quotes to the assembler.)

I also uploaded the resulting directory (including all sources, GPL-compliant) to https://pushbx.org/ecm/test/20230104/

The fdkernel.zip file downloaded at the beginning is my automatic build of the latest FreeDOS kernel sources, using tkchia's gcc-ia16 that targets 8086 machines. You can use tom's special kernel.sys instead for an otherwise identical build, but I will not host it without sources.

$ wget https://pushbx.org/ecm/download/fdkernel.zip -q
$ unzip -j fdkernel.zip bin/kernel.sys
Archive:  fdkernel.zip
  inflating: kernel.sys             
$ hg clone https://hg.pushbx.org/ecm/lmacros
destination directory: lmacros
requesting all changes
adding changesets
adding manifests
adding file changes
added 153 changesets with 183 changes to 40 files
new changesets 3a982025dd94:99b01fa65007
updating to branch default
31 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg clone https://hg.pushbx.org/ecm/ldosboot
destination directory: ldosboot
requesting all changes
adding changesets
adding manifests
adding file changes
added 671 changesets with 755 changes to 16 files (+2 heads)
new changesets 13cf6bb0b5f5:53d3efebfa44
updating to branch default
16 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg clone https://hg.pushbx.org/ecm/scanptab
destination directory: scanptab
requesting all changes
adding changesets
adding manifests
adding file changes
added 10 changesets with 10 changes to 1 files
new changesets ec30db08fa90:0e53081c1531
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd ldosboot
$ nasm fdkernpl.asm -I ../lmacros/ -D_PAYLOAD_FILE="'../kernel.sys'" -o fdkernpl.bin
$ nasm iniload.asm -I ../lmacros/ -I ../scanptab/ -D_PAYLOAD_FILE="'fdkernpl.bin'" -D_INILOAD_SIGNATURE="'FD'" -o ../io.sys
iniload.asm:813: warning: 1 bytes in front of ms7_entry [-w+user]
iniload.asm:1212: warning: 1 bytes in front of ldos_entry [-w+user]
iniload.asm:1613: warning: 1 bytes in front of end [-w+user]
iniload.asm:1687: warning: 427 bytes in front of end2 [-w+user]
$

---
l
Richard

10.11.2022, 13:11

@ Japheth
 

WDe and GPT, booting DOS

Post reply

> Some details where FD may differ from MS-DOS:
>
> - the MS-DOS kernel is named IO.SYS.
> - the boot code of DOS71BSG.BIN loads IO.SYS at 0070:0000
> - the boot code loads just the first 4 sectors of IO.SYS.
> - the boot code checks four bytes of loaded IO.SYS ( at pos 0 and pos 200h
> )
> - the boot code loads SI:DI with the start cluster of IO.SYS
> - the boot code of MS-DOS jumps to 0070:0200 to switch control to the
> kernel
> - when jumping, there are a few values on the stack that IO.SYS might use.
>
> So there's pretty much that may go wrong when using DOS71BSG for
> FreeDOS...:-D



So, I finally have M$DOS 7.1 installed on a spinning hard drive (which I swap with FreeDOS T2211 on a spinning hard drive - using a SATA extension cable for ease of access/change). I have never used DOS 71 before (only 6.22 and FreeDOS).


I attempted your method and I "think" that the 3 sectors of the FAT32 partition (of approx 2 GByte) have been modified correctly (I hope). Bytes from the ORIGINAL 3 sectors (0x0b to 0x59) were manually edited into DOS71BSM.bin (keeping DOS71BSG.bin unchanged) - attempted using WDE to replace the first 3 sectors with DOS71BSM.bin.




[image]





I have never used any GRUB programs before (except for dual boot (Windows + Linux) - where the whole GRUB process was automatic, no need for me to do anything).


Can you give me some guidance on how to actually perform the grub-mkconfig step? - I gather that this may have to be done in LINUX (I am learning/using Mint21) - assume that the M$DOS71 hard drive is /dev/sdd
Japheth

Homepage

Germany (South),
10.11.2022, 17:55

@ Richard
 

WDe and GPT, booting DOS

Post reply

> So, I finally have M$DOS 7.1 installed on a spinning hard drive (which I
> swap with FreeDOS T2211 on a spinning hard drive - using a SATA extension
> cable for ease of access/change). I have never used DOS 71 before (only
> 6.22 and FreeDOS).
I'd like to also have a solution for DOS 6.22, but that version doesn't understand LBA addressing, AFAIK, and that complicates things considerably.


> I attempted your method and I "think" that the 3 sectors of the FAT32
> partition (of approx 2 GByte) have been modified correctly (I hope). Bytes
> from the ORIGINAL 3 sectors (0x0b to 0x59) were manually edited into
> DOS71BSM.bin (keeping DOS71BSG.bin unchanged) - attempted using WDE to
> replace the first 3 sectors with DOS71BSM.bin.
Ok, here's the first mistake - or misunderstanding. The DOS71BSM.bin is the "standard" boot sector set for MBR-partitioned disks ( hence the 'M'-suffix ). It's more or less the "unmodified" DOS 7.1 FAT32 boot sector set - and pretty useless for GPT-partitioned disks ( I removed the creation of that binary in the meantime ). The interesting thing is DOS71BSG.bin ( 'G' for GPT-partitioned disks ), only that version contains the added modification.

> Can you give me some guidance on how to actually perform the grub-mkconfig
> step? - I gather that this may have to be done in LINUX (I am
> learning/using Mint21) - assume that the M$DOS71 hard drive is /dev/sdd
There are ( at least ) 2 possibilities: "grub-mkconfig" or "update-grub". The latter is better because it doesn't need any arguments. Must be run as root, though: "sudo update-grub".

If everything's ok, that program should finally display something like "found DOS/Win31 partition on /dev/sdd'.

---
MS-DOS forever!
Richard

22.11.2022, 07:10

@ Japheth
 

WDe and GPT, booting DOS

Post reply

>
> There are ( at least ) 2 possibilities: "grub-mkconfig" or "update-grub".
> The latter is better because it doesn't need any arguments. Must be run as
> root, though: "sudo update-grub".
>
> If everything's ok, that program should finally display something like
> "found DOS/Win31 partition on /dev/sdd'.



Nothing seems to work for me.


After a few re-installs on both INTEL and AMD Computers - the GNU GRUB version 2.06 menu looks like

Linux Mint 21 Cinnamon
Advanced options for Linux Mint 21 Cinnamon
FreeDOS (on /dev/sda2)
FreeDOS (on /dev/sda3)
UEFI Firmware Settings


Note that in above Menu - the "FreeDOS" is actually MSDOS71 - there is something about the MSDOS71.iso I have used to create MSDOS71 - there is actually reference to FreeDOS.


/dev/sda2 is actually the original MBR version of MSDOS71
/dev/sda3 is actually the Japheth GPT modifications of MSDOS71


When I select /dev/sda3 from the Menu I get the error


error: can't find command 'drivemap'
error: invalid EFI file path



Alternatively. if I via the GRUB Menu above, do
*UEFI Firmware Settings
F9 Boot Device Options
Notebook Hard Drive

in a DOS screen I get

A> type the name of the command interpreter (e.g. C:\Windows\command.com)

and no matter what I try e.g.

A> c:\command.com
A> d:\command.com
A> e:\command.com

etc

it just returns me to the prompt

A> type the name of the command interpreter...




Note that

In Windows 10, I used a Partition Assistant to copy the partition of the modified to GPT MSDOS71 - from the MBR partition style hard drive where the MSDOS71 (MBR) and MSDOS71 (GPT) were located - to a GPT partition style hard drive where Linux and Windows 10 also reside.

With my very limited knowledge of MBR and GPT - I guess that to use the GPT style MSDOS71, it would have to be located on a GPT style hard drive.

I could not locate genuine MSDOS71 to install - so I downloaded from way-back machine a MSDOS71 iso (which during installation makes mention of FreeDOS).

My computers date from about 2014 and onwards - my best computer has 3 BIOS settings

Legacy
CSM + UEFI
UEFI only

and for some reason LINUX + Windows only wants to work with UEFI only on a GPT Partition Style drive (in my case 4 TB) - I ensured that approx 500 MB partitions were within the first 2 TB for the MSDOS71 GPT.






For anyone who has tried the modifications for GPT (e.g. Japheth et al) - I assume the GPT version works for you - could you give some guidance on what I did wrong (e.g. not genuine MSDOS71, hardware too new, hard drive partition style incorrectly set, etc)?


Windows 10 "sees" both MBR and GPT versions of MSDOS71 (e.g. Explore in Disk Management) when these are on GPT Partition style Hard drive. MSDOS71 Fdisk seems to have trouble assigning the active partition when changing from MBR<->GPT version of MSDOS71 (being on a MBR Partition style hard drive).


Is it fair to say that the intention of the modification was to allow BOOTING of MSDOS71 from a GPT partition (rather than the GPT partition being only a Data Partition)?


If I understand the significance of WDe correctly -

It is a tool that can save to a file, a whole (or part thereof) partition.


The best I previously had to date was a partition assistant tool which CLONES a partition (i.e. does not generate a file).


WDe I think only works with drives (C D E etc) - any chance to let it explore any partition that is NOT a drive?
Rugxulo

Homepage

Usono,
22.11.2022, 09:00

@ Richard
 

WDe and GPT, booting DOS

Post reply

> WDe I think only works with drives (C D E etc) - any chance to let it
> explore any partition that is NOT a drive?
Doesn't it also support BIOS drives, e.g. "0", "1", "2"?
Japheth

Homepage

Germany (South),
22.11.2022, 09:52

@ Richard
 

WDe and GPT, booting DOS

Post reply

Hello,

well, that's a lot of text...

Honestly, I'm not totally sure if you know what you're doing - and that's a precondition for using the DOS71BSG thing. Another precondition is that you're quite familiar using a disk editor, preferably WDe - but apparently you didn't even read the WDe docs, because there it's clearly stated that this tool can access drives on a logical [ C:, D:, ... ] and physical [ HD 0, 1, ... ] level.

> /dev/sda2 is actually the original MBR version of MSDOS71
> /dev/sda3 is actually the Japheth GPT modifications of MSDOS71
I wonder how did you get the "modification" to /dev/sda3 without knowing how WDe can write to a physical disk?

> A> type the name of the command interpreter (e.g. C:\Windows\command.com)
If such a message appears, it most likely means that the bootstrap code has successfully read the kernel from a FAT disk and launched it, but after that DOS itself is unable to "mount" its C: drive.

---
MS-DOS forever!
Richard

22.11.2022, 12:29

@ Japheth
 

WDe and GPT, booting DOS

Post reply

Thanks for your reply.



> Honestly, I'm not totally sure if you know what you're doing -

I agree with that statement - I also do not know what I am doing in Windows 10 - programs that I compiled for use in Windows 10 two years ago now do not work properly (after an update) - no documentation seems to be available from M$ explaining the situation. As time passes by, I know even less of what Windows is doing.

OK, so I missed reading the "Physical" accessing (normally for me until fairly recently I was working from a single USB stick for DOS (bare metal) - so I only was used to the Logical drives.





> precondition for using the DOS71BSG thing. Another precondition is that
> you're quite familiar using a disk editor, preferably WDe -


I used WDE 1.00 (though not quite familiar with it) to obtain the info required for the DOS71BSG thing, saving to a file. Once the DOS71BSG.bin was modified, that modified file was WDE F2 (Restore from File) into the original Logical Drive.

>
> > /dev/sda2 is actually the original MBR version of MSDOS71
> > /dev/sda3 is actually the Japheth GPT modifications of MSDOS71
>
> I wonder how did you get the "modification" to /dev/sda3 without knowing
> how WDe can write to a physical disk?

I simply used a Windows 10 program to CLONE the modified partition to /dev/sda3
- is CLONING incorrect to use (e.g. because of any absolute addresses)?







>
> > A> type the name of the command interpreter (e.g.
> C:\Windows\command.com)
>
> If such a message appears, it most likely means that the bootstrap code has
> successfully read the kernel from a FAT disk and launched it, but after
> that DOS itself is unable to "mount" its C: drive.


Any clues what I can try???
Japheth

Homepage

Germany (South),
22.11.2022, 15:26

@ Richard
 

WDe and GPT, booting DOS

Post reply

> Any clues what I can try???
I'm not sure how WDe behaves if a drive is larger than 2 TB. That's why I'd suggest to try DOS71BSG on a disk < 2 TB first, if possible.

Then I would, as a first step, search the FAT32 boot partition on the GPT-partitioned disk with WDe and check that the bootsectors are indeed what they should be.

---
MS-DOS forever!
Richard

28.11.2022, 13:18

@ Japheth
 

WDe and GPT, booting DOS

Post reply

>
> I'm not sure how WDe behaves if a drive is larger than 2 TB. That's why I'd
> suggest to try DOS71BSG on a disk < 2 TB first, if possible.




I have just tried your "GPT modification recipe" on a wiped 750 GB spinning hard drive.







>
> Then I would, as a first step, search the FAT32 boot partition on the
> GPT-partitioned disk with WDe and check that the bootsectors are indeed
> what they should be.


It appears that the boot sectors are what they should be according to your recipe. I tried to use WDe 1.0 to save the modified DOS71BSG.BIN into the FAT32 partition (of the GPT style Disk) - but that did not work for me - so I CLONED the modified DOS71 FAT32 (on MBR style Disk) to the (GPT style disk).




Booting up from (GPT style disk) via GRUB produces the errors :-

no such drive EC01-CEA4
can't find command 'drivemap'
hd1,gpt2 not found



Note that Mint Cinnamon 21 was installed after the cloning above was done - and Mint 21 created the GRUB Menu (and grub-update automatically).





The MSDOS71 on the (MBR style disk) - being modified by the recipe to GPT - appears to function as if nothing was changed. I would have thought that changing it to GPT would prevent it from working (on a MBR style disk).



How did everyone else manage to get booting from GPT style disk???



It appears that WDe 1.0 is not reading the GPT style disk correctly. For instance, I cannot seem to see the FAT32 partition (with modified first 3 sectors) in WDe correctly. WDe appears to read the MBR style disk correctly.
Japheth

Homepage

Germany (South),
28.11.2022, 16:57

@ Richard
 

WDe and GPT, booting DOS

Post reply

> I tried to use WDe 1.0 to save the modified DOS71BSG.BIN into the
> FAT32 partition (of the GPT style Disk) - but that did not work for me - so
> I CLONED the modified DOS71 FAT32 (on MBR style Disk) to the (GPT style
> disk).
> It appears that WDe 1.0 is not reading the GPT style disk correctly.
These are very vague informations. Can't you do better? IIRC, with rxdrv32, you used that nice "screen thief" utility. Why don't you use it now and show us a screen shot of your GPT disk's "protective MBR" ( using WDe, please! ) and also, if that isn't demanding too much, the GPT header and the first sector of the GPT entry table?

---
MS-DOS forever!
Richard

08.12.2022, 17:21
(edited by Richard, 09.12.2022, 00:55)

@ Japheth
 

WDe and GPT, booting DOS

Post reply

> These are very vague informations. Can't you do better? IIRC, with rxdrv32,
> you used that nice "screen thief" utility. Why don't you use it now and
> show us a screen shot of your GPT disk's "protective MBR" ( using WDe,
> please! ) and also, if that isn't demanding too much, the GPT header and
> the first sector of the GPT entry table?

I still cannot get the DOS BOOT from GPT to work


SYSTEM

My computers x64 were newer than about 2014 - all have UEFI and Legacy.

With people who successfully achieved DOS on GPT - how does it compare to my system?


I have the following only used for DOS on GPT tests:-

300GB spinning hard drive (for MBR preliminary work)
700GB spinning hard drive (for GPT testing)

The 300GB MBR disk has the following partitions
C: 516MB (label MBR_D71)
D: 297GB (label MBR_data)

The 700GB GPT disk has the following partitions (initially)
L: 516MB (label "Clone") - for location of the modified DOS71 partition
M: 665GB (label GPT_data)

All partitions FAT32

The 300GB MBR disk was prepared as follows

MSDOS71 (~9 MB) was installed on C: with label MBR_D71
Some additional files were installed also, such as
FDisk, uHEX, WDE 1.00, JWASM, ScreenThief (Screen Capture program), etc and some very minor adjustments to config.sys/autoexec.bat
The ScreenThief program (ST.exe) was auto-installed with the switch /O:TXT to allow screen captures AS TEXT FILES ONLY.

The recipe to modify the MBR partition follows the instructions given by Japheth - and relevant ST.exe text screenshots are



INITIAL CONDITIONS



<c_BOOTre.txt    DISC 0 C Drive>

 Offset: 000  Sector: 0            [Boot/Reserved]
 0000    EB 58 90 4D  53 57 49 4E  34 2E 31 00  02 08 FE 17     X MSWIN4.1
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 08 00 00            ?
 0020    00 20 10 00  01 04 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 00 29 77  59 78 16 4E  4F 20 4E 41  4D 45 20 20      )wYx NO NAME
 0050    20 20 46 41  54 33 32 20  20 20 FA 33  C9 8E D1 BC      FAT32    3
 0060    F8 7B 8E C1  BD 78 00 C5  76 00 1E 56  16 55 BF 22     {   x  v  V U "
 0070    05 89 7E 00  89 4E 02 B1  0B FC F3 A4  8E D9 BD 00      ~  N
 0080    7C C6 45 FE  0F 8B 46 18  88 45 F9 38  4E 40 7D 25    | E   F  E 8N@}%
 0090    8B C1 99 BB  00 07 E8 97  00 72 1A 83  EB 3A 66 A1             r   :f
 00A0    1C 7C 66 3B  07 8A 57 FC  75 06 80 CA  02 88 56 02     |f;  W u     V
 00B0    80 C3 10 73  ED BF 02 00  83 7E 16 00  75 45 8B 46       s     ~  uE F
 00C0    1C 8B 56 1E  B9 03 00 49  40 75 01 42  BB 00 7E E8      V    I@u B  ~
 00D0    5F 00 73 26  B0 F8 4F 74  1D 8B 46 32  33 D2 B9 03    _ s&  Ot  F23
 00E0    00 3B C8 77  1E 8B 76 0E  3B CE 73 17  2B F1 03 46     ; w  v ; s +  F
 00F0    1C 13 56 1E  EB D1 73 0B  EB 27 83 7E  2A 00 77 03      V   s  ' ~* w
 0100    E9 FD 02 BE  7E 7D AC 98  03 F0 AC 84  C0 74 17 3C        ~}       t <
 0110    FF 74 09 B4  0E BB 07 00  CD 10 EB EE  BE 81 7D EB     t            }
 0120    E5 BE 7F 7D  EB E0 98 CD  16 5E 1F 66  8F 04 CD 19       }     ^ f
 0130    41 56 66 6A  00 52 50 06  53 6A 01 6A  10 8B F4 60    AVfj RP Sj j   `
 0140    80 7E 02 0E  75 04 B4 42  EB 1D 91 92  33 D2 F7 76     ~  u  B    3  v
 0150    18 91 F7 76  18 42 87 CA  F7 76 1A 8A  F2 8A E8 C0       v B   v
 0160    CC 02 0A CC  B8 01 02 8A  56 40 CD 13  61 8D 64 10            V@  a d
 0170    5E 72 0A 40  75 01 42 03  5E 0B 49 75  B4 C3 03 18    ^r @u B ^ Iu
 0180    01 27 0D 0A  49 6E 76 61  6C 69 64 20  73 79 73 74     '  Invalid syst
 0190    65 6D 20 64  69 73 6B FF  0D 0A 44 69  73 6B 20 49    em disk   Disk I
 01A0    2F 4F 20 65  72 72 6F 72  FF 0D 0A 52  65 70 6C 61    /O error   Repla
 01B0    63 65 20 74  68 65 20 64  69 73 6B 2C  20 61 6E 64    ce the disk, and
 01C0    20 74 68 65  6E 20 70 72  65 73 73 20  61 6E 79 20     then press any
 01D0    6B 65 79 0D  0A 00 00 00  49 4F 20 20  20 20 20 20    key     IO
 01E0    53 59 53 4D  53 44 4F 53  20 20 20 53  59 53 7E 01    SYSMSDOS   SYS~
 01F0    00 57 49 4E  42 4F 4F 54  20 53 59 53  00 00 55 AA     WINBOOT SYS  U
 
 Bytes per Sector:     512              Sectors per Cluster:   8
 Reserved Sectors:     6142             FATs:                  2
 Maximum Root Entries: 0                Media Descriptor:      248
 Sectors per Fat:      1025             Partition Start:       2048
 Sectors in Partition: 1056768          Hard Disk Number:      128 (0)
 Root Start Cluster:   2                FSInfo Sector Number:  1
 Backup B.S. Location: 6                Signature:             AA55
 
 F1-Help   F2-File   F3-Goto   F4-View   F5-Find   F6-Functions   F7-Save






 <Bytes to duplicate into DOS71BSG.BIN information which was loaded into the BOOT/reserved>

 Offset: 000  Sector: 0            [Boot/Reserved]
 0000                                       00  02 08 FE 17     X MSWIN4.1
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 08 00 00            ?
 0020    00 20 10 00  01 04 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 00 29 77  59 78 16 4E  4F 20 4E 41  4D 45 20 20      )wYx NO NAME
 0050    20 20 46 41  54 33 32 20  20 20                         FAT32    3







<modify.txt the bytes that were to be changed in the DOS71BSG.BIN information loaded into the BOOT/Reserved)

 00000000                                    00 02 00 20 00    X MSWIN4.1
 00000010  02 00 00 00 00 F8 00 00  3F 00 FF 00 00 00 00 00           ?
 00000020  00 00 00 00 00 00 00 00  00 00 00 00 02 00 00 00
 00000030  01 00 06 00 00 00 00 00  00 00 00 00 00 00 00 00
 00000040  80 00 29 00 00 00 00 20  20 20 20 20 20 20 20 20     )
 00000050  20 20 46 41 54 33 32 20  20 20                       FAT32    3
 dos71bsg.bin (1536 bytes)                       ALT+H: Help  offset: 0x00000000





The 3 sectors (1536 bytes) of DOS71BSG.BIN using WDE 1.00 were loaded into the FAT32 BOOT/RESERVED partition (of size approx 516 MB)
Using WDE, the relevant bytes were changed (0x0B - 0xc9) and saved.


On the last attempt of above - the computer crashed - and the "modified" MBR style disc will now no longer from a cold start, boot up into MSDOS71.
(Previous modification runs did not crash - i.e. could carry on with WDE)


The last screenshots up to the computer crash (prior to trying to use WDE to save anything to Disc 1 (GPT style partition disc)



<WDE01.txt>

 Offset: 000  Sector: 0            [Boot/Reserved]
 0000    EB 58 90 4D  53 57 49 4E  34 2E 31 00  02 08 FE 17     X MSWIN4.1
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 08 00 00            ?
 0020    00 20 10 00  01 04 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 00 29 77  59 78 16 4E  4F 20 4E 41  4D 45 20 20      )wYx NO NAME
 0050    20 20 46 41  54 33 32 20  20 20 FA 33  C9 8E D1 BC      FAT32    3
 0060    F8 7B 8E C1  BD 78 00 C5  76 00 1E 56  16 55 BF 22     {   x  v  V U "
 0070    05 89 7E 00  89 4E 02 B1  0B FC F3 A4  8E D9 BD 00      ~  N
 0080    7C C6 45 FE  0F 8B 46 18  88 45 F9 38  4E 40 7D 25    | E   F  E 8N@}%
 0090    8B C1 99 BB  00 07 E8 97  00 72 1A 83  EB 3A 66 A1             r   :f
 00A0    1C 7C 66 3B  07 8A 57 FC  75 06 80 CA  02 88 56 02     |f;  W u     V
 00B0    80 C3 10 73  ED BF 02 00  83 7E 16 00  75 45 8B 46       s     ~  uE F
 00C0    1C 8B 56 1E  B9 03 00 49  40 75 01 42  BB 00 7E E8      V    I@u B  ~
 00D0    5F 00 73 26  B0 F8 4F 74  1D 8B 46 32  33 D2 B9 03    _ s&  Ot  F23
 00E0    00 3B C8 77  1E 8B 76 0E  3B CE 73 17  2B F1 03 46     ; w  v ; s +  F
 00F0    1C 13 56 1E  EB D1 73 0B  EB 27 83 7E  2A 00 77 03      V   s  ' ~* w
 0100    E9 FD 02 BE  7E 7D AC 98  03 F0 AC 84  C0 74 17 3C        ~}       t <
 0110    FF 74 09 B4  0E BB 07 00  CD 10 EB EE  BE 81 7D EB     t            }
 0120    E5 BE 7F 7D  EB E0 98 CD  16 5E 1F 66  8F 04 CD 19       }     ^ f
 0130    41 56 66 6A  00 52 50 06  53 6A 01 6A  10 8B F4 60    AVfj RP Sj j   `
 0140    80 7E 02 0E  75 04 B4 42  EB 1D 91 92  33 D2 F7 76     ~  u  B    3  v
 0150    18 91 F7 76  18 42 87 CA  F7 76 1A 8A  F2 8A E8 C0       v B   v
 0160    CC 02 0A CC  B8 01 02 8A  56 40 CD 13  61 8D 64 10            V@  a d
 0170    5E 72 0A 40  75 01 42 03  5E 0B 49 75  B4 C3 03 18    ^r @u B ^ Iu
 0180    01 27 0D 0A  49 6E 76 61  6C 69 64 20  73 79 73 74     '  Invalid syst
 0190    65 6D 20 64  69 73 6B FF  0D 0A 44 69  73 6B 20 49    em disk   Disk I
 01A0    2F 4F 20 65  72 72 6F 72  FF 0D 0A 52  65 70 6C 61    /O error   Repla
 01B0    63 65 20 74  68 65 20 64  69 73 6B 2C  20 61 6E 64    ce the disk, and
 01C0    20 74 68 65  6E 20 70 72  65 73 73 20  61 6E 79 20     then press any
 01D0    6B 65 79 0D  0A 00 00 00  49 4F 20 20  20 20 20 20    key     IO
 01E0    53 59 53 4D  53 44 4F 53  20 20 20 53  59 53 7E 01    SYSMSDOS   SYS~
 01F0    00 57 49 4E  42 4F 4F 54  20 53 59 53  00 00 55 AA     WINBOOT SYS  U
 
 Bytes per Sector:     512              Sectors per Cluster:   8
 Reserved Sectors:     6142             FATs:                  2
 Maximum Root Entries: 0                Media Descriptor:      248
 Sectors per Fat:      1025             Partition Start:       2048
 Sectors in Partition: 1056768          Hard Disk Number:      128 (0)
 Root Start Cluster:   2                FSInfo Sector Number:  1
 Backup B.S. Location: 6                Signature:             AA55
 
 F1-Help   F2-File   F3-Goto   F4-View   F5-Find   F6-Functions   F7-Save






<WDE02.txt>

 Offset: 000  Sector: 0            [Boot/Reserved]
 0000    EB 58 90 4D  53 57 49 4E  34 2E 31 00  02 00 20 00     X MSWIN4.1
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 00 00 00            ?
 0020    00 00 00 00  00 00 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 00 29 00  00 00 00 20  20 20 20 20  20 20 20 20      )
 0050    20 20 46 41  54 33 32 20  20 20 FA 33  C9 8E D1 BC      FAT32    3
 0060    F8 7B 8E C1  BD 78 00 C5  76 00 1E 56  16 55 BF 22     {   x  v  V U "
 0070    05 89 7E 00  89 4E 02 B1  0B FC F3 A4  8E D9 BD 00      ~  N
 0080    7C C6 45 FE  0F 8B 46 18  88 45 F9 38  4E 40 7D 25    | E   F  E 8N@}%
 0090    8B C1 99 BB  00 07 E8 97  00 72 1A 83  EB 3A 66 A1             r   :f
 00A0    1C 7C 66 3B  07 8A 57 FC  90 90 B2 0E  90 88 56 02     |f;  W       V
 00B0    80 C3 10 73  ED BF 02 00  83 7E 16 00  75 45 8B 46       s     ~  uE F
 00C0    1C 8B 56 1E  B9 03 00 49  40 75 01 42  BB 00 7E E8      V    I@u B  ~
 00D0    5F 00 73 26  B0 F8 4F 74  1D 8B 46 32  33 D2 B9 03    _ s&  Ot  F23
 00E0    00 3B C8 77  1E 8B 76 0E  3B CE 73 17  2B F1 03 46     ; w  v ; s +  F
 00F0    1C 13 56 1E  EB D1 73 0B  EB 27 83 7E  2A 00 77 03      V   s  ' ~* w
 0100    E9 FD 02 BE  7E 7D AC 98  03 F0 AC 84  C0 74 17 3C        ~}       t <
 0110    FF 74 09 B4  0E BB 07 00  CD 10 EB EE  BE 81 7D EB     t            }
 0120    E5 BE 7F 7D  EB E0 98 CD  16 5E 1F 66  8F 04 CD 19       }     ^ f
 0130    41 56 66 6A  00 52 50 06  53 6A 01 6A  10 8B F4 60    AVfj RP Sj j   `
 0140    80 7E 02 0E  75 04 B4 42  EB 1D 91 92  33 D2 F7 76     ~  u  B    3  v
 0150    18 91 F7 76  18 42 87 CA  F7 76 1A 8A  F2 8A E8 C0       v B   v
 0160    CC 02 0A CC  B8 01 02 8A  56 40 CD 13  61 8D 64 10            V@  a d
 0170    5E 72 0A 40  75 01 42 03  5E 0B 49 75  B4 C3 03 18    ^r @u B ^ Iu
 0180    01 27 0D 0A  55 6E 67 75  65 6C 74 69  67 65 73 20     '  Ungueltiges
 0190    53 79 73 74  65 6D 20 FF  0D 0A 45 2F  41 2D 46 65    System    E/A-Fe
 01A0    68 6C 65 72  20 20 20 20  FF 0D 0A 44  61 74 65 6E    hler       Daten
 01B0    74 72 61 65  67 65 72 20  77 65 63 68  73 65 6C 6E    traeger wechseln
 01C0    20 75 6E 64  20 54 61 73  74 65 20 64  72 75 65 63     und Taste druec
 01D0    6B 65 6E 0D  0A 00 00 00  49 4F 20 20  20 20 20 20    ken     IO
 01E0    53 59 53 4D  53 44 4F 53  20 20 20 53  59 53 7E 01    SYSMSDOS   SYS~
 01F0    00 57 49 4E  42 4F 4F 54  20 53 59 53  00 00 55 AA     WINBOOT SYS  U
 
 Finished Writing to Disk - Press Any Key


<WDE03.txt>

 Offset: 05B  Sector: 0            [Boot/Reserved]
 0000    EB 58 90 4D  53 57 49 4E  34 2E 31 00  02 08 FE 17     X MSWIN4.1
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 00 00 00            ?
 0020    00 20 10 00  01 04 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 00 29 77  59 78 16 4E  4F 20 4E 41  4D 45 20 20      )wYx NO NAME
 0050    20 20 46 41  54 33 32 20  20 20 FA 33  C9 8E D1 BC      FAT32    3
 0060    F8 7B 8E C1  BD 78 00 C5  76 00 1E 56  16 55 BF 22     {   x  v  V U "
 0070    05 89 7E 00  89 4E 02 B1  0B FC F3 A4  8E D9 BD 00      ~  N
 0080    7C C6 45 FE  0F 8B 46 18  88 45 F9 38  4E 40 7D 25    | E   F  E 8N@}%
 0090    8B C1 99 BB  00 07 E8 97  00 72 1A 83  EB 3A 66 A1             r   :f
 00A0    1C 7C 66 3B  07 8A 57 FC  90 90 B2 0E  90 88 56 02     |f;  W       V
 00B0    80 C3 10 73  ED BF 02 00  83 7E 16 00  75 45 8B 46       s     ~  uE F
 00C0    1C 8B 56 1E  B9 03 00 49  40 75 01 42  BB 00 7E E8      V    I@u B  ~
 00D0    5F 00 73 26  B0 F8 4F 74  1D 8B 46 32  33 D2 B9 03    _ s&  Ot  F23
 00E0    00 3B C8 77  1E 8B 76 0E  3B CE 73 17  2B F1 03 46     ; w  v ; s +  F
 00F0    1C 13 56 1E  EB D1 73 0B  EB 27 83 7E  2A 00 77 03      V   s  ' ~* w
 0100    E9 FD 02 BE  7E 7D AC 98  03 F0 AC 84  C0 74 17 3C        ~}       t <
 0110    FF 74 09 B4  0E BB 07 00  CD 10 EB EE  BE 81 7D EB     t            }
 0120    E5 BE 7F 7D  EB E0 98 CD  16 5E 1F 66  8F 04 CD 19       }     ^ f
 0130    41 56 66 6A  00 52 50 06  53 6A 01 6A  10 8B F4 60    AVfj RP Sj j   `
 0140    80 7E 02 0E  75 04 B4 42  EB 1D 91 92  33 D2 F7 76     ~  u  B    3  v
 0150    18 91 F7 76  18 42 87 CA  F7 76 1A 8A  F2 8A E8 C0       v B   v
 0160    CC 02 0A CC  B8 01 02 8A  56 40 CD 13  61 8D 64 10            V@  a d
 0170    5E 72 0A 40  75 01 42 03  5E 0B 49 75  B4 C3 03 18    ^r @u B ^ Iu
 0180    01 27 0D 0A  55 6E 67 75  65 6C 74 69  67 65 73 20     '  Ungueltiges
 0190    53 79 73 74  65 6D 20 FF  0D 0A 45 2F  41 2D 46 65    System    E/A-Fe
 01A0    68 6C 65 72  20 20 20 20  FF 0D 0A 44  61 74 65 6E    hler       Daten
 01B0    74 72 61 65  67 65 72 20  77 65 63 68  73 65 6C 6E    traeger wechseln
 01C0    20 75 6E 64  20 54 61 73  74 65 20 64  72 75 65 63     und Taste druec
 01D0    6B 65 6E 0D  0A 00 00 00  49 4F 20 20  20 20 20 20    ken     IO
 01E0    53 59 53 4D  53 44 4F 53  20 20 20 53  59 53 7E 01    SYSMSDOS   SYS~
 01F0    00 57 49 4E  42 4F 4F 54  20 53 59 53  00 00 55 AA     WINBOOT SYS  U
 
 Bytes per Sector:     512              Sectors per Cluster:   8
 Reserved Sectors:     6142             FATs:                  2
 Maximum Root Entries: 0                Media Descriptor:      248
 Sectors per Fat:      1025             Partition Start:       0
 Sectors in Partition: 1056768          Hard Disk Number:      128 (0)
 Root Start Cluster:   2                FSInfo Sector Number:  1
 Backup B.S. Location: 6                Signature:             AA55
 
 F1-Help   F2-File   F3-Goto   F4-View   F5-Find   F6-Functions   F7-Save


<WDE04.txt  Disc 0>

 Offset: 05B  Sector: 0            [Boot/Reserved]
 0000    EB 58 90 4D  53 57 49 4E  34 2E 31 00  02 08 FE 17     X MSWIN4.1
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 00 00 00            ?
 0020    00 20 10 00  01 04 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 00 29 77  59 78 16 4E  4F 20 4E 41  4D 45 20 20      )wYx NO NAME
 0050    20 20 46 41  54 33 32 20  20 20 FA 33  C9 8E D1 BC      FAT32    3
 0060    F8 7B 8E C1  BD 78 00 C5  76 00 1E 56  16 55 BF 22     {   x  v  V U "
 0070    05 89 7E 00  89 4E 02 B1  0B FC F3 A4  8E D9 BD 00      ~  N
 0080    7C C6 45 FE  0F 8B 46 18  88 45 F9 38  4E 40 7D 25    | E   F  E 8N@}%
 0090    8B C1 99 BB  00 07 E8 97  00 72 1A 83  EB 3A 66 A1             r   :f
 00A0    1C 7C 66 3B  07 8A 57 FC  90 90 B2 0E  90 88 56 02     |f;  W       V
 00B0    80 C3 10 73  ED BF 02 00  83 7E 16 00  75 45 8B 46       s     ~  uE F
 00C0    1C 8B 56 1E  B9 03 00 49  40 75 01 42  BB 00 7E E8      V    I@u B  ~
 00D0    5F 00 73 26  B0 F8 4F 74  1D 8B 46 32  33 D2 B9 03    _ s&  Ot  F23
 00E0    00 3B C8 77  1E 8B 76 0E  3B CE 73 17  2B F1 03 46     ; w  v ; s +  F
 00F0    1C 13 56 1E  EB D1 73 0B  EB 27 83 7E  2A 00 77 03      V   s  ' ~* w
 0100    E9 FD 02 BE  7E 7D AC 98  03 F0 AC 84  C0 74 17 3C        ~}       t <
 0110    FF 74 09 B4  0E BB 07 00  CD 10 EB EE  BE 81 7D EB     t            }
 0120    E5 BE 7F 7D  EB E0 98 CD  16 5E 1F 66  8F 04 CD 19       }     ^ f
 0130    41 56 66 6A  00 52 50 06  53 6A 01 6A  10 8B F4 60    AVfj RP Sj j   `
 0140    80 7E 02 0E  75 04 B4 42  EB 1D 91 92  33 D2 F7 76     ~  u  B    3  v
 0150    18 91 F7 76  18 42 87 CA  F7 76 1A 8A  F2 8A E8 C0       v B   v
 0160    CC 02 0A CC  B8 01 02 8A  56 40 CD 13  61 8D 64 10            V@  a d
 0170    5E 72 0A 40  75 01 42 03  5E 0B 49 75  B4 C3 03 18    ^r @u B ^ Iu
 0180    01 27 0D 0A  55 6E 67 75  65 6C 74 69  67 65 73 20     '  Ungueltiges
 0190    53 79 73 74  65 6D 20 FF  0D 0A 45 2F  41 2D 46 65    System    E/A-Fe
 01A0    68 6C 65 72  20 20 20 20  FF 0D 0A 44  61 74 65 6E    hler       Daten
 01B0    74 72 61 65  67 65 72 20  77 65 63 68  73 65 6C 6E    traeger wechseln
 01C0    20 75 6E 64  20 54 61 73  74 65 20 64  72 75 65 63     und Taste druec
 01D0    6B 65 6E 0D  0A 00 00 00  49 4F 20 20  20 20 20 20    ken     IO
 01E0    53 59 53 4D  53 44 4F 53  20 20 20 53  59 53 7E 01    SYSMSDOS   SYS~
 01F0    00 57 49 4E  42 4F 4F 54  20 53 59 53  00 00 55 AA     WINBOOT SYS  U
 
 Bytes per Sector:     512              Sectors per Cluster:   8
 Reserved Sectors:     6142             FATs:                  2
 Maximum Root Entries: 0                Media Descriptor:      248
 Sectors per Fat:      1025             Partition Start:       0
 Sectors in Partition: 1056768          Hard Disk Number:      128 (0)
 Root Start Cluster:   2                FSInfo Sector Number:  1
 Backup B.S. Location: 6                Signature:             AA55
 
 Finished Writing to Disk - Press Any Key


<WDE05.txt Disc 1>

 Offset: 05B  Sector: 0            [MBR]                       CHS: 0/0/1
 0000    EB 63 90 00  00 00 00 00  00 00 00 00  00 00 00 00     c
 0010    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0020    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0030    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0050    00 00 00 00  00 00 00 00  00 00 00 80  78 AD 26 02                x &
 0060    00 00 00 00  FF FA 90 90  F6 C2 80 74  05 F6 C2 70               t   p
 0070    74 02 B2 80  EA 79 7C 00  00 31 C0 8E  D8 8E D0 BC    t    y|  1
 0080    00 20 FB A0  64 7C 3C FF  74 02 88 C2  52 BB 17 04        d|< t   R
 0090    F6 07 03 74  06 BE 88 7D  E8 17 01 BE  05 7C B4 41       t   }     | A
 00A0    BB AA 55 CD  13 5A 52 72  3D 81 FB 55  AA 75 37 83      U  ZRr=  U u7
 00B0    E1 01 74 32  31 C0 89 44  04 40 88 44  FF 89 44 02      t21  D @ D  D
 00C0    C7 04 10 00  66 8B 1E 5C  7C 66 89 5C  08 66 8B 1E        f  \|f \ f
 00D0    60 7C 66 89  5C 0C C7 44  06 00 70 B4  42 CD 13 72    `|f \  D  p B  r
 00E0    05 BB 00 70  EB 76 B4 08  CD 13 73 0D  5A 84 D2 0F       p v    s Z
 00F0    83 D0 00 BE  93 7D E9 82  00 66 0F B6  C6 88 64 FF         }   f    d
 0100    40 66 89 44  04 0F B6 D1  C1 E2 02 88  E8 88 F4 40    @f D           @
 0110    89 44 08 0F  B6 C2 C0 E8  02 66 89 04  66 A1 60 7C     D       f  f `|
Japheth

Homepage

Germany (South),
09.12.2022, 05:10

@ Richard
 

WDe and GPT, booting DOS

Post reply

> My computers x64 were newer than about 2014 - all have UEFI and Legacy.
>
> With people who successfully achieved DOS on GPT - how does it compare to
> my system?
Your system is fine. What do you fear? That it's too old or new? So long as you can access your GPT-partitioned disk with WDe, it's ok.

> The 300GB MBR disk has the following partitions
> C: 516MB (label MBR_D71)
> D: 297GB (label MBR_data)
Why is C: so small? It's FAT32, but using CHS addressing mode, AFAICS ( partition type 0Bh then ) - thus it's restricted to be located on the first 8 GB of a disk.

> The recipe to modify the MBR partition follows the instructions given by
> Japheth
With "MBR partition" you probably mean "the ( first ) FAT32 partition on the MBR-partitioned disk"?

Well, here's a little problem. In my "recipe" I didn't mention to modify anything on a "MBR partition" ( using your wording here ). All HD editing was supposed to be done on the "GPT-partitioned" disk only. Actually, there's no need at all to even access your disk 0 ( the "MBR disk" ) with WDe.

Since you modified your disk 0, your system finally refused to boot. Not really surprising, and no big issue; it's "part of the business" if fumbling around with a disk editor - IMO there's no learning without a bit of pain.

Anyway, I like it that you don't give up if something doesn't work out of the box.

Your "GPT-partitioned" disk ( disk 1 for WDe ). looks quite good. There are 5 partitions on it, 2 of them labeled "Basic data partition" - these are the interesting ones, your FAT32 partitions. Be aware that in the GPT each partition entry occupies 128 ( 80h ) bytes.

The next step that you have to learn now is how to navigate to your FAT32 partitions on the GPT-partitioned disk. It's pretty easy with WDe - you just have to position the cursor to the partition entry in the GPT and then press ENTER.

---
MS-DOS forever!
Richard

11.12.2022, 03:08
(edited by Richard, 11.12.2022, 03:21)

@ Japheth
 

WDe and GPT, booting DOS

Post reply



EDIT

Think problem solved - Should be on sector 006 (not 000).






A strange problem is occurring.


I am using WDe1.00 and on loading DOS71BSG.bin (1536 bytes) for use on the GPT disc the number of sectors to load does not make sense to me (see below)








 Offset: 000  Sector: 0            [Boot/Reserved]
 0000    EB 58 90 4D  53 57 49 4E  34 2E 31 00  02 00 20 00     X MSWIN4.1
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 00 00 00            ?
 0020    00 00 00 00  00 00 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 00 29 00  00 00 00 20  20 20 20 20  20 20 20 20      )
 0050    20 20 46 41  54 33 32 20  20 20 FA 33  C9 8E D1 BC      FAT32    3
 0060    F8 7B 8E C1  BD 78 00 C5  76 00 1E 56  16 55 BF 22     {   x  v  V U "
 0070    05 89 7E 00  89 4E 02 B1  0B FC F3 A4  8E D9 BD 00      ~  N
 0080    7C C6 45 FE  0F 8B 46 18  88 45 F9 38  4E 40 7D 25    | E   F  E 8N@}%
 0090    8B C1 99 BB  00 07 E8 97  00 72 1A 83  EB 3A 66 A1             r   :f
 00A0    1C 7C 66 3B  07 8A 57 FC  90 90 B2 0E  90 88 56 02     |f;  W       V
 00B0    80 C3 10 73  ED BF 02 00  83 7E 16 00  75 45 8B 46       s     ~  uE F
 00C0    1C 8B 56 1E  B9 03 00 49  40 75 01 42  BB 00 7E E8      V    I@u B  ~
 00D0    5F 00 73 26  B0 F8 4F 74  1D 8B 46 32  33 D2 B9 03    _ s&  Ot  F23
 00E0    00 3B C8 77  1E 8B 76 0E  3B CE 73 17  2B F1 03 46     ; w  v ; s +  F
 00F0    1C 13 56 1E  EB D1 73 0B  EB 27 83 7E  2A 00 77 03      V   s  ' ~* w
 0100    E9 FD 02 BE  7E 7D AC 98  03 F0 AC 84  C0 74 17 3C        ~}       t <
 0110    FF 74 09 B4  0E BB 07 00  CD 10 EB EE  BE 81 7D EB     t            }
 0120    E5 BE 7F 7D  EB E0 98 CD  16 5E 1F 66  8F 04 CD 19       }     ^ f
 0130    41 56 66 6A  00 52 50 06  53 6A 01 6A  10 8B F4 60    AVfj RP Sj j   `
 0140    80 7E 02 0E  75 04 B4 42  EB 1D 91 92  33 D2 F7 76     ~  u  B    3  v
 0150    18 91 F7 76  18 42 87 CA  F7 76 1A 8A  F2 8A E8 C0       v B   v
 0160    CC 02 0A CC  B8 01 02 8A  56 40 CD 13  61 8D 64 10            V@  a d
 0170    5E 72 0A 40  75 01 42 03  5E 0B 49 75  B4 C3 03 18    ^r @u B ^ Iu
 0180    01 27 0D 0A  55 6E 67 75  65 6C 74 69  67 65 73 20     '  Ungueltiges
 0190    53 79 73 74  65 6D 20 FF  0D 0A 45 2F  41 2D 46 65    System    E/A-Fe
 01A0    68 6C 65 72  20 20 20 20  FF 0D 0A 44  61 74 65 6E    hler       Daten
 01B0    74 72 61 65  67 65 72 20  77 65 63 68  73 65 6C 6E    traeger wechseln
 01C0    20 75 6E 64  20 54 61 73  74 65 20 64  72 75 65 63     und Taste druec
 01D0    6B 65 6E 0D  0A 00 00 00  49 4F 20 20  20 20 20 20    ken     IO
 01E0    53 59 53 4D  53 44 4F 53  20 20 20 53  59 53 7E 01    SYSMSDOS   SYS~
 01F0    00 57 49 4E  42 4F 4F 54  20 53 59 53  00 00 55 AA     WINBOOT SYS  U
 
 Bytes per Sector:     512              Sectors per Cluster:   0
 Reserved Sectors:     32               FATs:                  2
 Maximum Root Entries: 0                Media Descriptor:      248
 Sectors per Fat:      0                Partition Start:       0
 Sectors in Partition: 0                Hard Disk Number:      128 (0)
 Root Start Cluster:   2                FSInfo Sector Number:  1
 Backup B.S. Location: 6                Signature:             AA55
 
 Number of Sectors (1-0):










It used to say (last line)

Number of Sectors (1-3):



and now frequently getting errors (writing to disc).



Even if DOS71BSG.BIN (1536 bytes) was corrupt - it should still show 1-3 sectors (as it did before many times). I also randomly tried (silly) large files (~3000 bytes) and still shows (1-0).

I checked current WDE.com (7-11-2022) on my MBR disc with the freshly unzipped WDE100.zip and both instances of WDE.com are reported identical.


Would you advise me to completely WIPE the MBR disc and reinstall MSDOS71 etc - at present I do not have a spare hard drive to replicate the MBR disc.


Any ideas on what might be going wrong?





EDIT

Think problem solved - Should be on sector 006 (not 000).
Japheth

Homepage

Germany (South),
11.12.2022, 10:39

@ Richard
 

WDe and GPT, booting DOS

Post reply

> Think problem solved - Should be on sector 006 (not 000).
That's pretty unlikely. Sector 6 on FAT32 is commonly used to store the "backup" bootsector. How do you come to your conclusion?

> I am using WDe1.00 and on loading DOS71BSG.bin (1536 bytes) for use on the
> GPT disc the number of sectors to load does not make sense to me (see
> below)
 [snip]
> Bytes per Sector: 512 Sectors per Cluster: 0
> Reserved Sectors: 32 FATs: 2
> Maximum Root Entries: 0 Media Descriptor: 248
> Sectors per Fat: 0 Partition Start: 0
> Sectors in Partition: 0 Hard Disk Number: 128 (0)
> Root Start Cluster: 2 FSInfo Sector Number: 1
> Backup B.S. Location: 6 Signature: AA55
>
> Number of Sectors (1-0):
Well, as you can see, the values of many fields in the boot sector are kind of "invalid" - the one that may cause this strance msg is "Sectors in Partition". A partition size of 0 is definitely something that WDe cannot handle properly.


> Would you advise me to completely WIPE the MBR disc and reinstall MSDOS71
> etc - at present I do not have a spare hard drive to replicate the MBR
> disc.
The problem most likely is that you modified sectors 0-2 of partition 1 ( drive C:) of your MBR-partitioned disk. You'll have to boot from USB-stick, and use FDISK to delete/create the partition again - unless you've make a backup copy and stored it somewhere "safe".

> Any ideas on what might be going wrong?
Quite a few things might go wrong - this stuff actually is intended for experienced users that know each byte of the boot sector by its first name.

You have to learn to describe EXACTLY what you did - in the actual case, I suspect that it was you who created that "useless" boot sector with partition size 0. After all, you couldn't have followed the recipe exactly, because - at least until recently - you didn't know how to navigate with WDe to the FAT32 partitions on the "GPT disk".

---
MS-DOS forever!
Richard

11.12.2022, 14:53

@ Japheth
 

WDe and GPT, booting DOS

Post reply

Thank you for your advice/help.


I have just found out that my MBR disc (with MSDOS71 installed), now does not boot - for the last few trials I was only using the MBR disc to run WDe on the GPT disc (i.e. no editing of anything on the MBR disc) and to save the screen captures on the MBR disc.

I will WIPE with sudo shred both the MBR and GPT discs and reinstall MSDOS71 on MBR and WDE edit only for the GPT (taking as many screen captures as possible).


Yesterday I could get the following screen capture (from which I could navigate to the First Basic Data partition (FAT32) - today I could not get this screen capture information.





 Offset: 100  Sector: 2            [GPT]                       CHS: 0/0/3
 0000    28 73 2A C1  1F F8 D2 11  BA 4B 00 A0  C9 3E C9 3B    (s*      K   > ;
 0010    F7 E9 08 DF  55 84 A6 4E  B6 16 37 80  0A E5 C5 73        U  N  7    s
 0020    00 08 00 00  00 00 00 00  FF 27 08 00  00 00 00 00             '
 0030    00 00 00 00  00 00 00 80  45 00 46 00  49 00 20 00            E F I
 0040    73 00 79 00  73 00 74 00  65 00 6D 00  20 00 70 00    s y s t e m   p
 0050    61 00 72 00  74 00 69 00  74 00 69 00  6F 00 6E 00    a r t i t i o n
 0060    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0070    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0080    16 E3 C9 E3  5C 0B B8 4D  81 7D F9 2D  F0 02 15 AE        \  M } -
 0090    02 DC 69 BC  68 6F A0 4C  A0 96 15 70  73 E4 4E D4      i ho L   ps N
 00A0    00 28 08 00  00 00 00 00  FF A7 08 00  00 00 00 00     (
 00B0    00 00 00 00  00 00 00 80  4D 00 69 00  63 00 72 00            M i c r
 00C0    6F 00 73 00  6F 00 66 00  74 00 20 00  72 00 65 00    o s o f t   r e
 00D0    73 00 65 00  72 00 76 00  65 00 64 00  20 00 70 00    s e r v e d   p
 00E0    61 00 72 00  74 00 69 00  74 00 69 00  6F 00 6E 00    a r t i t i o n
 00F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0100    A2 A0 D0 EB  E5 B9 33 44  87 C0 68 B6  B7 26 99 C7          3D  h  &
 0110    C9 F8 74 3F  7C 5D A0 4D  A3 43 B4 B2  31 C1 33 C9      t?|] M C  1 3
 0120    00 A8 08 00  00 00 00 00  FF 7F 86 72  00 00 00 00               r
 0130    00 00 00 00  00 00 00 00  42 00 61 00  73 00 69 00            B a s i
 0140    63 00 20 00  64 00 61 00  74 00 61 00  20 00 70 00    c   d a t a   p
 0150    61 00 72 00  74 00 69 00  74 00 69 00  6F 00 6E 00    a r t i t i o n
 0160    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0170    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0180    A4 BB 94 DE  D1 06 40 4D  A1 6A BF D5  01 79 D6 AC          @M j   y
 0190    75 BF 9B 10  4B CA 48 4D  AA 88 A8 D3  7A 81 22 F5    u   K HM    z "
 01A0    00 80 86 72  00 00 00 00  FF 1F A5 72  00 00 00 00       r       r
 01B0    01 00 00 00  00 00 00 80  42 00 61 00  73 00 69 00            B a s i
 01C0    63 00 20 00  64 00 61 00  74 00 61 00  20 00 70 00    c   d a t a   p
 01D0    61 00 72 00  74 00 69 00  74 00 69 00  6F 00 6E 00    a r t i t i o n
 01E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 
 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 567296                      Last LBA: 1921417215
 Size: 937915 MB                        Flags: 0
 Name: Basic data partition
 
 
 
 
 F1-Help   F2-File   F3-Goto   F4-View   F5-Find   F6-Functions   F7-Save
Japheth

Homepage

Germany (South),
12.12.2022, 10:34

@ Richard
 

WDe and GPT, booting DOS

Post reply

> Yesterday I could get the following screen capture (from which I could
> navigate to the First Basic Data partition (FAT32)
That's the crucial point: knowing WDe enough so you are able to navigate to the correct location.


> Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
> First LBA: 567296                      Last LBA: 1921417215
> Size: 937915 MB                        Flags: 0
> Name: Basic data partition

As you can see, this is a rather large partition ( 940 GB ), so probably not the one you want to boot from.

My advise is: don't be so eager to modify anything with WDe. In a first step, create the FAT32 partition ( using Windows/Linux tools? ) and make GRUB add it in its boot menu. That's not entirely trivial, because GRUB expects a few things to be found on the partition before it accepts it as something that's bootable.

Only AFTER this is done, WDe will be used...

---
MS-DOS forever!
Richard

21.12.2022, 17:30

@ Japheth
 

WDe and GPT, booting DOS

Post reply

> ... That's not entirely trivial, because GRUB
> expects a few things to be found on the partition before it accepts it as
> something that's bootable.
>
> ...





Finally, after a "rocky-road roller-coaster ride", my results with MSDOS71 on GPT are shown in the screenshots below.





8 GB SSD SATA GPT with 64 MB DOS 71 partition with MINT 19 (grub 2.02)




[image]


[image]


[image]


[image]


[image]










 Offset: 080  Sector: 0            [MBR]                       CHS: 0/0/1
 0000    EB 63 90 00  00 00 00 00  00 00 00 00  00 00 00 00     c
 0010    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0020    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0030    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0050    00 00 00 00  00 00 00 00  00 00 00 80  18 71 AF 00                 q
 0060    00 00 00 00  FF FA 90 90  F6 C2 80 74  05 F6 C2 70               t   p
 0070    74 02 B2 80  EA 79 7C 00  00 31 C0 8E  D8 8E D0 BC    t    y|  1
 0080    00 20 FB A0  64 7C 3C FF  74 02 88 C2  52 BB 17 04        d|< t   R
 0090    F6 07 03 74  06 BE 88 7D  E8 17 01 BE  05 7C B4 41       t   }     | A
 00A0    BB AA 55 CD  13 5A 52 72  3D 81 FB 55  AA 75 37 83      U  ZRr=  U u7
 00B0    E1 01 74 32  31 C0 89 44  04 40 88 44  FF 89 44 02      t21  D @ D  D
 00C0    C7 04 10 00  66 8B 1E 5C  7C 66 89 5C  08 66 8B 1E        f  \|f \ f
 00D0    60 7C 66 89  5C 0C C7 44  06 00 70 B4  42 CD 13 72    `|f \  D  p B  r
 00E0    05 BB 00 70  EB 76 B4 08  CD 13 73 0D  5A 84 D2 0F       p v    s Z
 00F0    83 D0 00 BE  93 7D E9 82  00 66 0F B6  C6 88 64 FF         }   f    d
 0100    40 66 89 44  04 0F B6 D1  C1 E2 02 88  E8 88 F4 40    @f D           @
 0110    89 44 08 0F  B6 C2 C0 E8  02 66 89 04  66 A1 60 7C     D       f  f `|
 0120    66 09 C0 75  4E 66 A1 5C  7C 66 31 D2  66 F7 34 88    f  uNf \|f1 f 4
 0130    D1 31 D2 66  F7 74 04 3B  44 08 7D 37  FE C1 88 C5     1 f t ;D }7
 0140    30 C0 C1 E8  02 08 C1 88  D0 5A 88 C6  BB 00 70 8E    0        Z    p
 0150    C3 31 DB B8  01 02 CD 13  72 1E 8C C3  60 1E B9 00     1      r   `
 0160    01 8E DB 31  F6 BF 00 80  8E C6 FC F3  A5 1F 61 FF       1          a
 0170    26 5A 7C BE  8E 7D EB 03  BE 9D 7D E8  34 00 BE A2    &Z|  }    } 4
 0180    7D E8 2E 00  CD 18 EB FE  47 52 55 42  20 00 47 65    } .     GRUB  Ge
 0190    6F 6D 00 48  61 72 64 20  44 69 73 6B  00 52 65 61    om Hard Disk Rea
 01A0    64 00 20 45  72 72 6F 72  0D 0A 00 BB  01 00 B4 0E    d  Error
 01B0    CD 10 AC 3C  00 75 F4 C3  11 CA 28 7B  00 00 00 00       < u    ({
 01C0    01 00 EE FE  FF CE 01 00  00 00 AF C9  EE 00 00 00
 01D0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 55 AA                  U
 
 P Type             Boot Start-CHS   End-CHS     Start-LBA  Size       MB
 ------------------------------------------------------------------------------
 1 EE EFI           00   0/0/1       974/254/63  1          15649199   7641
 2 00 Unused        00   0/0/0       0/0/0       0          0          0
 3 00 Unused        00   0/0/0       0/0/0       0          0          0
 4 00 Unused        00   0/0/0       0/0/0       0          0          0
 
 
 F1-Help   F2-File   F3-Goto   F4-View   F5-Find   F6-Functions   F7-Save







 Offset: 080  Sector: 1            [GPT Hdr]                   CHS: 0/0/2
 0000    45 46 49 20  50 41 52 54  00 00 01 00  5C 00 00 00    EFI PART    \
 0010    5C 51 76 DF  00 00 00 00  01 00 00 00  00 00 00 00    \Qv
 0020    AB C9 EE 00  00 00 00 00  22 00 00 00  00 00 00 00            "
 0030    8A C9 EE 00  00 00 00 00  F8 0A CD 5E  16 63 0C 44               ^ c D
 0040    84 37 3C F0  A4 31 DB A5  02 00 00 00  00 00 00 00     7<  1
 0050    80 00 00 00  80 00 00 00  6F A7 B6 91  00 00 00 00            o
 0060    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0070    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0080    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0090    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00A0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00B0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00C0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00D0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0100    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0110    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0120    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0130    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0140    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0150    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0160    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0170    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0180    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0190    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01A0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01B0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01C0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01D0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 
 Signature:            EFI PART         Size GPT Header:       92
 CRC (disk):           DF76515C         CRC (calculated):      df76515c
 Current LBA:          1                Backup LBA:            15649195
 First LBA:            34               Last LBA:              15649162
 Start GPT:            2                Entries GPT:           128
 Size GPT Entry:       128              CRC GPT Entries:       91B6A76F
 
 
 F1-Help   F2-File   F3-Goto   F4-View   F5-Find   F6-Functions   F7-Save





 Offset: 080  Sector: 2            [GPT]                       CHS: 0/0/3
 0000    16 E3 C9 E3  5C 0B B8 4D  81 7D F9 2D  F0 02 15 AE        \  M } -
 0010    E1 AB C0 A8  DC 66 B6 42  8E 68 46 8E  E6 CE 3B 2D         f B hF   ;-
 0020    22 00 00 00  00 00 00 00  FF 7F 00 00  00 00 00 00    "
 0030    00 00 00 00  00 00 00 00  4D 00 69 00  63 00 72 00            M i c r
 0040    6F 00 73 00  6F 00 66 00  74 00 20 00  72 00 65 00    o s o f t   r e
 0050    73 00 65 00  72 00 76 00  65 00 64 00  20 00 70 00    s e r v e d   p
 0060    61 00 72 00  74 00 69 00  74 00 69 00  6F 00 6E 00    a r t i t i o n
 0070    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0080    A2 A0 D0 EB  E5 B9 33 44  87 C0 68 B6  B7 26 99 C7          3D  h  &
 0090    B0 C5 E7 4B  4B 16 51 4B  95 65 72 52  5F 44 85 47       KK QK erR_D G
 00A0    00 80 00 00  00 00 00 00  FF 7F 02 00  00 00 00 00
 00B0    00 00 00 00  00 00 00 00  42 00 61 00  73 00 69 00            B a s i
 00C0    63 00 20 00  64 00 61 00  74 00 61 00  20 00 70 00    c   d a t a   p
 00D0    61 00 72 00  74 00 69 00  74 00 69 00  6F 00 6E 00    a r t i t i o n
 00E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0100    28 73 2A C1  1F F8 D2 11  BA 4B 00 A0  C9 3E C9 3B    (s*      K   > ;
 0110    00 77 7A 8F  95 F3 70 45  A9 D9 5C 6B  E6 88 1A 82     wz   pE  \k
 0120    00 80 02 00  00 00 00 00  FF 9F 05 00  00 00 00 00
 0130    00 00 00 00  00 00 00 00  45 00 46 00  49 00 20 00            E F I
 0140    53 00 79 00  73 00 74 00  65 00 6D 00  20 00 50 00    S y s t e m   P
 0150    61 00 72 00  74 00 69 00  74 00 69 00  6F 00 6E 00    a r t i t i o n
 0160    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0170    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0180    A2 A0 D0 EB  E5 B9 33 44  87 C0 68 B6  B7 26 99 C7          3D  h  &
 0190    BE 76 42 C4  7B 5B 90 4A  95 BA 2E E8  5F E4 E2 CE     vB {[ J  . _
 01A0    00 A0 05 00  00 00 00 00  FF DF 05 00  00 00 00 00
 01B0    00 00 00 00  00 00 00 00  42 00 61 00  73 00 69 00            B a s i
 01C0    63 00 20 00  64 00 61 00  74 00 61 00  20 00 70 00    c   d a t a   p
 01D0    61 00 72 00  74 00 69 00  74 00 69 00  6F 00 6E 00    a r t i t i o n
 01E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 
 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 32768                       Last LBA: 163839
 Size: 64 MB                            Flags: 0
 Name: Basic data partition
 
 
 
 
 F1-Help   F2-File   F3-Goto   F4-View   F5-Find   F6-Functions   F7-Save




 Offset: 080  Sector: 3            [GPT]                       CHS: 0/0/4
 0000    A2 A0 D0 EB  E5 B9 33 44  87 C0 68 B6  B7 26 99 C7          3D  h  &
 0010    2F B0 C9 4D  11 26 05 4D  B0 2B 22 8D  2C D4 B0 89    /  M & M +" ,
 0020    00 C8 EA 00  00 00 00 00  FF C7 EC 00  00 00 00 00
 0030    00 00 00 00  00 00 00 00  42 00 61 00  73 00 69 00            B a s i
 0040    63 00 20 00  64 00 61 00  74 00 61 00  20 00 70 00    c   d a t a   p
 0050    61 00 72 00  74 00 69 00  74 00 69 00  6F 00 6E 00    a r t i t i o n
 0060    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0070    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0080    A2 A0 D0 EB  E5 B9 33 44  87 C0 68 B6  B7 26 99 C7          3D  h  &
 0090    8D A7 E9 E4  AF 32 B4 49  93 90 99 74  88 4A C9 90         2 I   t J
 00A0    00 C8 EC 00  00 00 00 00  FF BF EE 00  00 00 00 00
 00B0    00 00 00 00  00 00 00 00  42 00 61 00  73 00 69 00            B a s i
 00C0    63 00 20 00  64 00 61 00  74 00 61 00  20 00 70 00    c   d a t a   p
 00D0    61 00 72 00  74 00 69 00  74 00 69 00  6F 00 6E 00    a r t i t i o n
 00E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0100    AF 3D C6 0F  83 84 72 47  8E 79 3D 69  D8 47 7D E4     =    rG y=i G}
 0110    04 69 4F E6  F1 87 9E 48  A3 C4 8F D9  EF 05 6E 8A     iO    H      n
 0120    00 E0 05 00  00 00 00 00  FF C7 EA 00  00 00 00 00
 0130    00 00 00 00  00 00 00 00  4D 00 49 00  4E 00 54 00            M I N T
 0140    20 00 31 00  39 00 00 00  00 00 00 00  00 00 00 00      1 9
 0150    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0160    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0170    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0180    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0190    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01A0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01B0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01C0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01D0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 
 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 15517696                    Last LBA: 15646719
 Size: 63 MB                            Flags: 0
 Name: Basic data partition
 
 
 
 
 F1-Help   F2-File   F3-Goto   F4-View   F5-Find   F6-Functions   F7-Save




 Offset: 000  Sector: 32768        [Data]                      CHS: 32/8/9
 0000    EB 58 90 4D  53 44 4F 53  35 2E 30 00  02 01 7E 18     X MSDOS5.0   ~
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 80 00 00            ?
 0020    00 00 02 00  C1 03 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 00 29 91  D2 42 28 4E  4F 20 4E 41  4D 45 20 20      )  B(NO NAME
 0050    20 20 46 41  54 33 32 20  20 20 33 C9  8E D1 BC F4      FAT32   3
 0060    7B 8E C1 8E  D9 BD 00 7C  88 56 40 88  4E 02 8A 56    {      | V@ N  V
 0070    40 B4 41 BB  AA 55 CD 13  72 10 81 FB  55 AA 75 0A    @ A  U  r   U u
 0080    F6 C1 01 74  05 FE 46 02  EB 2D 8A 56  40 B4 08 CD       t  F  - V@
 0090    13 73 05 B9  FF FF 8A F1  66 0F B6 C6  40 66 0F B6     s      f   @f
 00A0    D1 80 E2 3F  F7 E2 86 CD  C0 ED 06 41  66 0F B7 C9       ?       Af
 00B0    66 F7 E1 66  89 46 F8 83  7E 16 00 75  39 83 7E 2A    f  f F  ~  u9 ~*
 00C0    00 77 33 66  8B 46 1C 66  83 C0 0C BB  00 80 B9 01     w3f F f
 00D0    00 E8 2C 00  E9 A8 03 A1  F8 7D 80 C4  7C 8B F0 AC      ,      }  |
 00E0    84 C0 74 17  3C FF 74 09  B4 0E BB 07  00 CD 10 EB      t < t
 00F0    EE A1 FA 7D  EB E4 A1 7D  80 EB DF 98  CD 16 CD 19       }   }
 0100    66 60 80 7E  02 00 0F 84  20 00 66 6A  00 66 50 06    f` ~      fj fP
 0110    53 66 68 10  00 01 00 B4  42 8A 56 40  8B F4 CD 13    Sfh     B V@
 0120    66 58 66 58  66 58 66 58  EB 33 66 3B  46 F8 72 03    fXfXfXfX 3f;F r
 0130    F9 EB 2A 66  33 D2 66 0F  B7 4E 18 66  F7 F1 FE C2      *f3 f  N f
 0140    8A CA 66 8B  D0 66 C1 EA  10 F7 76 1A  86 D6 8A 56      f  f    v    V
 0150    40 8A E8 C0  E4 06 0A CC  B8 01 02 CD  13 66 61 0F    @            fa
 0160    82 74 FF 81  C3 00 02 66  40 49 75 94  C3 42 4F 4F     t     f@Iu  BOO
 0170    54 4D 47 52  20 20 20 20  00 00 00 00  00 00 00 00    TMGR
 0180    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0190    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01A0    00 00 00 00  00 00 00 00  00 00 00 00  0D 0A 44 69                  Di
 01B0    73 6B 20 65  72 72 6F 72  FF 0D 0A 50  72 65 73 73    sk error   Press
 01C0    20 61 6E 79  20 6B 65 79  20 74 6F 20  72 65 73 74     any key to rest
 01D0    61 72 74 0D  0A 00 00 00  00 00 00 00  00 00 00 00    art
 01E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01F0    00 00 00 00  00 00 00 00  AC 01 B9 01  00 00 55 AA                  U
 
 
 
 
 
 
 
 
 
 F1-Help   F2-File   F3-Goto   F4-View   F5-Find   F6-Functions   F7-Save






dos71bsg.bin (1536 bytes)


 00000000                                          00   02 00 20 00    X MSWIN4.1
 00000010    02 00 00 00   00 F8 00 00    3F 00 FF 00   00 00 00 00           ?
 00000020    00 00 00 00   00 00 00 00    00 00 00 00   02 00 00 00
 00000030    01 00 06 00   00 00 00 00    00 00 00 00   00 00 00 00
 00000040    80 00 29 00   00 00 00 20    20 20 20 20   20 20 20 20     )
 00000050    20 20 46 41   54 33 32 20    20 20                         FAT32    3





Replicate.bin

 Offset: 000  Sector: 32768        [Data]                      CHS: 32/8/9
 

 ....0000                                          00   02 01 7E 18     X MSDOS5.0   ~
 ....0010    02 00 00 00   00 F8 00 00    3F 00 FF 00   00 80 00 00            ?
 ....0020    00 00 02 00   C1 03 00 00    00 00 00 00   02 00 00 00
 ....0030    01 00 06 00   00 00 00 00    00 00 00 00   00 00 00 00
 ....0040    80 00 29 91   D2 42 28 4E    4F 20 4E 41   4D 45 20 20      )  B(NO NAME
 ....0050    20 20 46 41   54 33 32 20    20 20                          FAT32   3





AUTOEXEC.bat


@ECHO OFF
PROMPT $P$G
SET DIRCMD=/4
MODE CON RATE=32 DELAY=1
REM MODE CON CP PREPARE=((437)EGA.CPI)
REM MODE CON CP SELECT=437
REM KEYB US,,KEYBOARD.SYS
LH KILLER
LH DOSKEY
LH DOSLFN /Z:C:\DOS71\CP437UNI.TBL
LH MSCDEX /D:IDE-CD
LH SHARE /L:30
LH NLSFUNC
LH SMARTDRV
LH CTMOUSE
REM For compatiblity purpose:
LH CTMOUSE > NUL
ECHO.
REM For locking volumes to enable "direct disk access":
CALL LOCKDRV.BAT
BREAK ON
LFNFOR ON
ECHO Now you are in MS-DOS 7.10 prompt. Type 'HELP' for help.
ECHO.
c:\sound\envmastr.exe /l winbootdir=
c:\sound\ctcm.exe


PATH=c:\_;c:\dos;C:\DOS71;..;;C:\DOS71\norton
ST.exe /o:txt




CONFIG.sys


device=c:\resti13.sys

DEVICE=C:\DOS71\ECHO.SYS W/e/l/c/o/m/e /t/o MS-DOS 7.10...
DEVICE=C:\DOS71\ECHO.SYS C/o/p/y/r/i/g/h/t M/i/c/r/o/s/o/f/t C/o/r/p. A/l/l /r/i/g/h/t/s /r/e/s/e/r/v/e/d.
DEVICE=C:\DOS71\HIMEM.SYS
DEVICE=C:\DOS71\EMM386.EXE NOEMS
DEVICEHIGH=C:\DOS71\SETVER.EXE
DEVICEHIGH=C:\DOS71\POWER.EXE
DEVICEHIGH=C:\DOS71\VIDE-CDD.SYS /D:IDE-CD
REM DEVICEHIGH=C:\DOS71\DISPLAY.SYS CON=(,,1)
COUNTRY=001,437,C:\DOS71\COUNTRY.SYS
SHELL=COMMAND.COM /P /E:640
DOS=HIGH,UMB,AUTO
FCBS=4,0
FILES=30
BUFFERS=20,0
LASTDRIVE=26
STACKS=9,256

SET PATH=c:\_;c:\dos;C:\DOS71;..;







Also works for a GPT 4TB SSD SATA drive with 8 GB DOS 71, 1 TB Windows 10 and 500 GB Mint 21.1(grub 2.06), and 2200 GB NTFS partitions (but Windows could not be made to triple boot).






Question.


How to edit /boot/grub/grub.cfg?

I wish to have Menu selections for Mint 21.1, Windows 10 and MS-DOS71.

So far, grub only allows for me either:-

Mint + DOS71
Mint + Windows

The respective parts of grub.cfg are




### BEGIN /etc/grub.d/30_os-prober ###
menuentry 'MS-DOS 5.x/6.x/Win3.1 (on /dev/sda2)' --class ms_dos --class os $menuentry_id_option 'osprober-chain-5230-F0FE' {
insmod part_gpt
insmod fat
set root='hd0,gpt2'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2 5230-F0FE
else
search --no-floppy --fs-uuid --set=root 5230-F0FE
fi
drivemap -s (hd0) ${root}
chainloader +1
}
set timeout_style=menu
if [ "${timeout}" = 0 ]; then
set timeout=10
fi
### END /etc/grub.d/30_os-prober ###






### BEGIN /etc/grub.d/40_custom_proxy ###
menuentry "Windows Boot Manager (on /dev/sda5)" --class windows --class os $menuentry_id_option 'osprober-efi-202E-600C' {
insmod part_gpt
insmod fat
set root='hd0,gpt5'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt5 --hint-efi=hd0,gpt5 --hint-baremetal=ahci0,gpt5 202E-600C
else
search --no-floppy --fs-uuid --set=root 202E-600C
fi
chainloader /EFI/Microsoft/Boot/bootmgfw.efi
}
### END /etc/grub.d/40_custom_proxy ###




No matter what I tried (referring to the internet) I am prevented from saving the edited grub.cfg file because of "Permission denied" error.











So, MS-DOS 7.1 on GPT is working for me - just in time for Xmas :-)
glennmcc

Homepage E-mail

North Jackson, Ohio (USA),
21.12.2022, 19:07

@ Richard
 

WDe and GPT, booting DOS

Post reply

>
> No matter what I tried (referring to the internet) I am prevented from
> saving the edited grub.cfg file because of "Permission denied" error.
Were you logged-in as root ?

And are the permissions on grub.cfg set to allow writing ?

---
--
http://glennmcc.org/
Japheth

Homepage

Germany (South),
22.12.2022, 14:52

@ Richard
 

WDe and GPT, booting DOS

Post reply

> Also works for a GPT 4TB SSD SATA drive with 8 GB DOS 71, 1 TB
> Windows 10 and 500 GB Mint 21.1(grub 2.06), and 2200 GB NTFS partitions
> (but Windows could not be made to triple boot).
Congratulations! You're now a member of a very elitist club. :-P

> Question.
>
>
> How to edit /boot/grub/grub.cfg?
IIRC it's not a very good idea to edit that file directly - it will be overwritten whenever grub or the kernel has been updated.

---
MS-DOS forever!
glennmcc

Homepage E-mail

North Jackson, Ohio (USA),
22.12.2022, 18:41

@ Japheth
 

WDe and GPT, booting DOS

Post reply

> > Also works for a GPT 4TB SSD SATA drive with 8 GB DOS 71, 1 TB
> > Windows 10 and 500 GB Mint 21.1(grub 2.06), and 2200 GB NTFS partitions
> > (but Windows could not be made to triple boot).
>
> Congratulations! You're now a member of a very elitist club. :-P
>
> > Question.
> >
> >
> > How to edit /boot/grub/grub.cfg?
>
> IIRC it's not a very good idea to edit that file directly - it will be
> overwritten whenever grub or the kernel has been updated.
Quite correct.

This is how to do it....

Edit /etc/default/grub then run update-grub
(as root or via sudo)

Reboot and you should now be able to get to DOS from the grub menu.

---
--
http://glennmcc.org/
Richard

23.12.2022, 01:49
(edited by Richard, 23.12.2022, 02:08)

@ glennmcc
 

WDe and GPT, booting DOS

Post reply

> > > Also works for a GPT 4TB SSD SATA drive with 8 GB DOS 71, 1 TB
> > > Windows 10 and 500 GB Mint 21.1(grub 2.06), and 2200 GB NTFS
> partitions
> > > (but Windows could not be made to triple boot).
> >
> > Congratulations! You're now a member of a very elitist club. :-P
> >
> > > Question.
> > >
> > >
> > > How to edit /boot/grub/grub.cfg?
> >
> > IIRC it's not a very good idea to edit that file directly - it will be
> > overwritten whenever grub or the kernel has been updated.
>
> Quite correct.
>
> This is how to do it....
>
> Edit /etc/default/grub then run update-grub
> (as root or via sudo)
>
> Reboot and you should now be able to get to DOS from the grub menu.











Problem with editing /etc/default/grub


sudo update-grub (no edit changes)


[image]



sudo -i allowed permission to sudoedit /etc/default/grub which originally was


# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
# info -f grub -n 'Simple configuration'

GRUB_DEFAULT="0"
GRUB_TIMEOUT_STYLE="hidden"
GRUB_TIMEOUT="10"
GRUB_DISTRIBUTOR="`lsb_release -i -s 2> /dev/null || echo Debian`"
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"

# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL="console"

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE="640x480"

# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
#GRUB_DISABLE_LINUX_UUID="true"

# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY="true"

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"








edited /etc/default/grub to include MSDOS stuff stuff added at the end



# TEST FOR EDIT_CHANGE
# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
# info -f grub -n 'Simple configuration'

GRUB_DEFAULT="0"
GRUB_TIMEOUT_STYLE="hidden"
GRUB_TIMEOUT="10"
GRUB_DISTRIBUTOR="`lsb_release -i -s 2> /dev/null || echo Debian`"
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"

# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL="console"

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE="640x480"

# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
#GRUB_DISABLE_LINUX_UUID="true"

# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY="true"

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"


### BEGIN /etc/grub.d/30_os-prober ###
menuentry 'MS-DOS 5.x/6.x/Win3.1 (on /dev/sda2)' --class ms_dos --class os $menuentry_id_option 'osprober-chain-5230-F0FE' {
insmod part_gpt
insmod fat
set root='hd0,gpt2'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2 5230-F0FE
else
search --no-floppy --fs-uuid --set=root 5230-F0FE
fi
drivemap -s (hd0) ${root}
chainloader +1
}
set timeout_style=menu
if [ "${timeout}" = 0 ]; then
set timeout=10
fi
### END /etc/grub.d/30_os-prober ###





sudo update-grub


[image]









/boot/grub/grub.cfg listing




#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
set have_grubenv=true
load_env
fi
if [ "${initrdfail}" = 2 ]; then
set initrdfail=
elif [ "${initrdfail}" = 1 ]; then
set next_entry="${prev_entry}"
set prev_entry=
save_env prev_entry
if [ "${next_entry}" ]; then
set initrdfail=2
fi
fi
if [ "${next_entry}" ] ; then
set default="${next_entry}"
set next_entry=
save_env next_entry
set boot_once=true
else
set default="0"
fi

if [ x"${feature_menuentry_id}" = xy ]; then
menuentry_id_option="--id"
else
menuentry_id_option=""
fi

export menuentry_id_option

if [ "${prev_saved_entry}" ]; then
set saved_entry="${prev_saved_entry}"
save_env saved_entry
set prev_saved_entry=
save_env prev_saved_entry
set boot_once=true
fi

function savedefault {
if [ -z "${boot_once}" ]; then
saved_entry="${chosen}"
save_env saved_entry
fi
}
function initrdfail {
if [ -n "${have_grubenv}" ]; then if [ -n "${partuuid}" ]; then
if [ -z "${initrdfail}" ]; then
set initrdfail=1
if [ -n "${boot_once}" ]; then
set prev_entry="${default}"
save_env prev_entry
fi
fi
save_env initrdfail
fi; fi
}
function recordfail {
set recordfail=1
if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi
}
function load_video {
if [ x$feature_all_video_module = xy ]; then
insmod all_video
else
insmod efi_gop
insmod efi_uga
insmod ieee1275_fb
insmod vbe
insmod vga
insmod video_bochs
insmod video_cirrus
fi
}

if [ x$feature_default_font_path = xy ] ; then
font=unicode
else
insmod part_gpt
insmod ext2
set root='hd0,gpt8'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt8 --hint-efi=hd0,gpt8 --hint-baremetal=ahci0,gpt8 f19f7536-4cd7-40d4-b785-1ed717ec0ccf
else
search --no-floppy --fs-uuid --set=root f19f7536-4cd7-40d4-b785-1ed717ec0ccf
fi
font="/usr/share/grub/unicode.pf2"
fi

if loadfont $font ; then
set gfxmode=auto
load_video
insmod gfxterm
set locale_dir=$prefix/locale
set lang=en_AU
insmod gettext
fi
terminal_output gfxterm
if [ "${recordfail}" = 1 ] ; then
set timeout=30
else
if [ x$feature_timeout_style = xy ] ; then
set timeout_style=hidden
set timeout=10
# Fallback hidden-timeout code in case the timeout_style feature is
# unavailable.
elif sleep --interruptible 10 ; then
set timeout=0
fi
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=white/black
set menu_color_highlight=black/light-gray
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
function gfxmode {
set gfxpayload="${1}"
if [ "${1}" = "keep" ]; then
set vt_handoff=vt.handoff=7
else
set vt_handoff=
fi
}
if [ "${recordfail}" != 1 ]; then
if [ -e ${prefix}/gfxblacklist.txt ]; then
if [ ${grub_platform} != pc ]; then
set linux_gfx_mode=keep
elif hwmatch ${prefix}/gfxblacklist.txt 3; then
if [ ${match} = 0 ]; then
set linux_gfx_mode=keep
else
set linux_gfx_mode=text
fi
else
set linux_gfx_mode=text
fi
else
set linux_gfx_mode=keep
fi
else
set linux_gfx_mode=text
fi
export linux_gfx_mode
menuentry 'Linux Mint 21.1 Cinnamon' --class linuxmint --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-f19f7536-4cd7-40d4-b785-1ed717ec0ccf' {
recordfail
load_video
gfxmode $linux_gfx_mode
insmod gzio
if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
insmod part_gpt
insmod ext2
set root='hd0,gpt8'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt8 --hint-efi=hd0,gpt8 --hint-baremetal=ahci0,gpt8 f19f7536-4cd7-40d4-b785-1ed717ec0ccf
else
search --no-floppy --fs-uuid --set=root f19f7536-4cd7-40d4-b785-1ed717ec0ccf
fi
linux /boot/vmlinuz-5.15.0-56-generic root=UUID=f19f7536-4cd7-40d4-b785-1ed717ec0ccf ro quiet splash
initrd /boot/initrd.img-5.15.0-56-generic
}
submenu 'Advanced options for Linux Mint 21.1 Cinnamon' $menuentry_id_option 'gnulinux-advanced-f19f7536-4cd7-40d4-b785-1ed717ec0ccf' {
menuentry 'Linux Mint 21.1 Cinnamon, with Linux 5.15.0-56-generic' --class linuxmint --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.15.0-56-generic-advanced-f19f7536-4cd7-40d4-b785-1ed717ec0ccf' {
recordfail
load_video
gfxmode $linux_gfx_mode
insmod gzio
if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
insmod part_gpt
insmod ext2
set root='hd0,gpt8'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt8 --hint-efi=hd0,gpt8 --hint-baremetal=ahci0,gpt8 f19f7536-4cd7-40d4-b785-1ed717ec0ccf
else
search --no-floppy --fs-uuid --set=root f19f7536-4cd7-40d4-b785-1ed717ec0ccf
fi
echo 'Loading Linux 5.15.0-56-generic ...'
linux /boot/vmlinuz-5.15.0-56-generic root=UUID=f19f7536-4cd7-40d4-b785-1ed717ec0ccf ro quiet splash
echo 'Loading initial ramdisk ...'
initrd /boot/initrd.img-5.15.0-56-generic
}
menuentry 'Linux Mint 21.1 Cinnamon, with Linux 5.15.0-56-generic (recovery mode)' --class linuxmint --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.15.0-56-generic-recovery-f19f7536-4cd7-40d4-b785-1ed717ec0ccf' {
recordfail
load_video
insmod gzio
if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
insmod part_gpt
insmod ext2
set root='hd0,gpt8'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt8 --hint-efi=hd0,gpt8 --hint-baremetal=ahci0,gpt8 f19f7536-4cd7-40d4-b785-1ed717ec0ccf
else
search --no-floppy --fs-uuid --set=root f19f7536-4cd7-40d4-b785-1ed717ec0ccf
fi
echo 'Loading Linux 5.15.0-56-generic ...'
linux /boot/vmlinuz-5.15.0-56-generic root=UUID=f19f7536-4cd7-40d4-b785-1ed717ec0ccf ro recovery nomodeset dis_ucode_ldr
echo 'Loading initial ramdisk ...'
initrd /boot/initrd.img-5.15.0-56-generic
}
}

### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/11_linux_zfs ###
### END /etc/grub.d/11_linux_zfs ###

### BEGIN /etc/grub.d/20_linux_xen ###

### END /etc/grub.d/20_linux_xen ###

### BEGIN /etc/grub.d/30_os-prober_proxy ###


set timeout_style=menu
if [ "${timeout}" = 0 ]; then
set timeout=10
fi
### END /etc/grub.d/30_os-prober_proxy ###

### BEGIN /etc/grub.d/40_custom_proxy ###
menuentry "Windows Boot Manager (on /dev/sda5)" --class windows --class os $menuentry_id_option 'osprober-efi-202E-600C' {
insmod part_gpt
insmod fat
set root='hd0,gpt5'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt5 --hint-efi=hd0,gpt5 --hint-baremetal=ahci0,gpt5 202E-600C
else
search --no-floppy --fs-uuid --set=root 202E-600C
fi
chainloader /EFI/Microsoft/Boot/bootmgfw.efi
}
### END /etc/grub.d/40_custom_proxy ###

### BEGIN /etc/grub.d/41_os-prober_proxy ###
### END /etc/grub.d/41_os-prober_proxy ###

### BEGIN /etc/grub.d/42_uefi-firmware ###
menuentry 'UEFI Firmware Settings' $menuentry_id_option 'uefi-firmware' {
fwsetup
}
### END /etc/grub.d/42_uefi-firmware ###

### BEGIN /etc/grub.d/43_fwupd ###
### END /etc/grub.d/43_fwupd ###

### BEGIN /etc/grub.d/44_custom_proxy ###

# This file provides an easy way to add custom menu entries. Simply type the
# menu entries you want to add after this comment. Be careful not to change
# the 'exec tail' line above.

### END /etc/grub.d/44_custom_proxy ###

### BEGIN /etc/grub.d/45_custom ###
if [ -f ${config_directory}/custom.cfg ]; then
source ${config_directory}/custom.cfg
elif [ -z "${config_directory}" -a -f $prefix/custom.cfg ]; then
source $prefix/custom.cfg
fi
### END /etc/grub.d/45_custom ###









How to fix the editing of /etc/default/grub to make sudo update-grub include MSDOS?












EDIT to ORIGINAL POST


[image]






/dev/sda2 is where MS-DOS 7.1 is located (label GPT_D71)

.
glennmcc

Homepage E-mail

North Jackson, Ohio (USA),
23.12.2022, 05:06

@ Richard
 

WDe and GPT, booting DOS

Post reply

>
> Problem with editing /etc/default/grub
>

The slashes might be "confusing" the grub-mkconfig process...

menuentry 'MS-DOS 5.x/6.x/Win3.1 (on /dev/sda2)'

Simplify it to...

menuentry 'MS-DOS'

___________

This has now become a Linux/GRUB question rather than a DOS question.

Perhaps ask for assistance at linuxquestions.org ? ;-)

---
--
http://glennmcc.org/
Richard

23.12.2022, 06:46

@ glennmcc
 

WDe and GPT, booting DOS

Post reply

> >
> > Problem with editing /etc/default/grub
> >
>
> The slashes might be "confusing" the grub-mkconfig process...
>
> menuentry 'MS-DOS 5.x/6.x/Win3.1 (on /dev/sda2)'
>
> Simplify it to...
>
> menuentry 'MS-DOS'
>
> ___________
>
> This has now become a Linux/GRUB question rather than a DOS question.
>
> Perhaps ask for assistance at linuxquestions.org ? ;-)


Simplyfying both to 'MS-DOS' and 'MS-DOS (on /dev/sda2)' with the rest of the line intact still gives the same sudo update-grub error.


I have on your advice, asked for assistance in my first post on LinuxQuestions.org.

Thanks for your help.
Richard

26.12.2022, 12:16

@ Japheth
 

WDe and GPT, booting DOS

Post reply

>
> Congratulations! You're now a member of a very elitist club. :-P
>

Pushing the limits


It seems I broke this Xmas present. :-)


On a GPT Partition Style 4 TB SSD SATA drive I cannot have a 524,288 MB partition (Windows 10 Disk Management New Simple Volume size entry) with MS-DOS 7.1 - it locks up.

I can only have a 524,287 MB partition with working MS-DOS 7.1.


On the other hand, I cannot have a FAT32 partition with GPT MS-DOS 7.1 smaller than 64 MB.



Screenshots of 524,287 MB GPT MS-DOS 7.1

[image]

[image]

[image]



Merry Christmas all (from Australia)
Richard

28.12.2022, 09:34

@ Japheth
 

WDe and GPT, booting DOS

Post reply

>
> Congratulations! You're now a member of a very elitist club. :-P
>


Pushing the limits (again)


I broke it (again)! :-)




So, it appears that I have discovered the upper size limit of a FAT32 GPT bootable DOS partition (which is smaller than the general Windows 10, paid partition tools and Wiki FAT32 partitions on GPT - all seem to have different but larger values).


To make better use of the first 2 TB of a 4 TB SATA SSD, and since only ~ 512 GB can be for FAT32 partition on GPT - I used Windows 10 to create an additional FAT32 partition of size 64 MB - the intention to use it only for data/files (not booting).


MS-DOS 7.1 on GPT did not see this extra partition (Dir D:\ gives invalid drive error).


I then attempted to use WDE to modify the first 1536 bytes of the 64 MB partition (along the lines of making the partition bootable) - but WDE crashed.

[image]

[image]

[image]

[image]

[image]

[image]

[image]

[image]

[image]
Japheth

Homepage

Germany (South),
28.12.2022, 12:05

@ Richard
 

WDe and GPT, booting DOS

Post reply

> So, it appears that I have discovered the upper size limit of a FAT32 GPT
> bootable DOS partition (which is smaller than the general Windows 10, paid
> partition tools and Wiki FAT32 partitions on GPT - all seem to have
> different but larger values).
Would be interesting to see if MS-DOS on a MBR-partitioned disk also has this 512 GB limit.

> MS-DOS 7.1 on GPT did not see this extra partition (Dir D:\ gives invalid
> drive error).
Yes, this isn't surprising. See one of the first posts:

> However, just the boot partition is detected and used ... to detect further
> FAT partitions ( including the "EFI system partition" ) would need more.
Would actually need a little device driver.


> I then attempted to use WDE to modify the first 1536 bytes of the 64 MB
> partition (along the lines of making the partition bootable) - but WDE
> crashed.
I agree, a divide error isn't very nice - perhaps this should be fixed...

---
MS-DOS forever!
Richard

28.12.2022, 17:27

@ Japheth
 

WDe and GPT, booting DOS

Post reply

>
> Would be interesting to see if MS-DOS on a MBR-partitioned disk also has
> this 512 GB limit.
>


Unless I did something wrong, I cannot create a MBR-style ~700 GB FAT32 MS-DOS 7.1 BOOTABLE disc.


Interestingly, I can install MS-DOS 7.1 via CD onto a 700 GB FAT32 MBR par style partition - but I cannot boot from it. The spinning hard drive capacity is 700 GB.


Also, from my CD MS-DOS 7.1 install, IO.sys, MSDOS.sys and some other files are missing


[image]


[image]


[image]


[image]


[image]


[image]
Japheth

Homepage

Germany (South),
29.12.2022, 19:32

@ Richard
 

WDe and GPT, booting DOS

Post reply

> Interestingly, I can install MS-DOS 7.1 via CD onto a 700 GB FAT32 MBR par
> style partition - but I cannot boot from it. The spinning hard drive
> capacity is 700 GB.

This is a guess only, but 128 sectors per cluster might be something that MS-DOS 7.1 is unable to digest.

>
>
> Also, from my CD MS-DOS 7.1 install, IO.sys, MSDOS.sys and some other
> files are missing

perhaps they're just "hidden"?

---
MS-DOS forever!
Richard

30.12.2022, 07:52

@ Japheth
 

WDe and GPT, booting DOS

Post reply

> >
> > Also, from my CD MS-DOS 7.1 install, IO.sys, MSDOS.sys and some other
> > files are missing
>
> perhaps they're just "hidden"?

For information only

Yes, they were hidden (used a windows app to confirm this).

If they were not there at all - I would have copied same there to see if could boot.


>
> This is a guess only, but 128 sectors per cluster might be something that
> MS-DOS 7.1 is unable to digest.
>
> >


Your guess would be a good explanation since the important boot files are present in the 700 GB partition (as they are in a 512 MB partition working boot).


700 GB MBR MS-DOS 7.1 directory

[image]




512 MB (Mega Byte) MBR MS-DOS 7.1 (partial) directory

[image]
Zyzzle

31.12.2022, 08:23

@ Japheth
 

WDe and GPT, booting DOS

Post reply

> This is a guess only, but 128 sectors per cluster might be something that
> MS-DOS 7.1 is unable to digest.
 In my experience, MS-DOS 7.1 handles 64 kib clusters just fine. 128 sectors / cluster is possible and works perfectly well, even for FAT32 drives. (This option allows one to format and use FAT16 drives up to 4 GiB in DOS).
Japheth

Homepage

Germany (South),
02.01.2023, 13:04

@ Zyzzle
 

WDe and GPT, booting DOS

Post reply

> In my experience, MS-DOS 7.1 handles 64 kib clusters just fine. 128 sectors
> / cluster is possible and works perfectly well, even for FAT32 drives.
Ok, so it must be something else.

My try:

1. create a "Basic Data Partition", size 720 GB, in Linux using fdisk
2. format the partition with mkfs.fat
3. copy the necessary files to that partition ( IO.SYS, COMMAND.COM, ... )
4. run update-grub, the (newly created) partition is added to the boot menu
5. reboot into DOS ( located on another bootable FAT partition )
6. launch WDe and modify the boot sectors of the 720 GB partition
7. reboot, this time selecting the 720 GB partition

It worked - however:

a). my 720 GB partition still has 64 sectors per cluster
b). had to remove SmartDrv from config.sys - looks like it cannot handle such large FAT32 partitions.

---
MS-DOS forever!
Richard

03.01.2023, 03:51

@ Zyzzle
 

WDe and GPT, booting DOS

Post reply

> > This is a guess only, but 128 sectors per cluster might be something
> that
> > MS-DOS 7.1 is unable to digest.
> In my experience, MS-DOS 7.1 handles 64 kib clusters just fine. 128 sectors
> / cluster is possible and works perfectly well, even for FAT32 drives.
> (This option allows one to format and use FAT16 drives up to 4 GiB in DOS).



Question - Does booting on a 128 sectors/cluster FAT32 partition with MS-DOS 7.1 work for you?


I can use FAT32 700 GB partition for data/files - but I cannot boot from same (using the auto-installed MS-DOS 7.1 from CD).



[image]





Also, just for fun, I edited the auto-installed files - changes shown in bold. The edits were only to REM out the original LH and CALL lines.


AUTOEXEC.BAT

@ECHO OFF
PROMPT $P$G
SET DIRCMD=/4
MODE CON RATE=32 DELAY=1
REM MODE CON CP PREPARE=((437)EGA.CPI)
REM MODE CON CP SELECT=437
REM KEYB US,,KEYBOARD.SYS
REM
rem LH KILLER
rem LH DOSKEY
rem LH DOSLFN /Z:C:\DOS71\CP437UNI.TBL
rem LH MSCDEX /D:IDE-CD
rem LH SHARE /L:30
rem LH NLSFUNC
rem LH SMARTDRV
REM
LH CTMOUSE
REM For compatiblity purpose:
LH CTMOUSE > NUL
ECHO.
REM For locking volumes to enable "direct disk access":
rem CALL LOCKDRV.BAT
rem
BREAK ON
LFNFOR ON
ECHO Now you are in MS-DOS 7.10 prompt. Type 'HELP' for help.
ECHO.
PATH=C:\DOS71;..;;C:\DOS71\norton




CONFIG.SYS (no changes)

DEVICE=C:\DOS71\ECHO.SYS W/e/l/c/o/m/e /t/o MS-DOS 7.10...
DEVICE=C:\DOS71\ECHO.SYS C/o/p/y/r/i/g/h/t M/i/c/r/o/s/o/f/t C/o/r/p. A/l/l /r/i/g/h/t/s /r/e/s/e/r/v/e/d.
DEVICE=C:\DOS71\HIMEM.SYS
DEVICE=C:\DOS71\EMM386.EXE NOEMS
DEVICEHIGH=C:\DOS71\SETVER.EXE
DEVICEHIGH=C:\DOS71\POWER.EXE
DEVICEHIGH=C:\DOS71\VIDE-CDD.SYS /D:IDE-CD
REM DEVICEHIGH=C:\DOS71\DISPLAY.SYS CON=(,,1)
COUNTRY=001,437,C:\DOS71\COUNTRY.SYS
SHELL=COMMAND.COM /P /E:640
DOS=HIGH,UMB,AUTO
FCBS=4,0
FILES=30
BUFFERS=20,0
LASTDRIVE=26
STACKS=9,256
SET PATH=C:\DOS71;..;



The above changes to AUTOEXEC.BAT/CONFIG.SYS does not give me a bootable partition either - just only a normal data partition (so can-do DIR for instance).



Anything else I can try before I try the following?

1. wipe partition and MANUALLY install minimal stuff (io.sys, command.com, ...) and set partition to active.

2. What Japheth did (including no SMARTDRV).
glennmcc

Homepage E-mail

North Jackson, Ohio (USA),
03.01.2023, 04:05

@ Richard
 

WDe and GPT, booting DOS

Post reply

> > > This is a guess only, but 128 sectors per cluster might be something
> > that
> > > MS-DOS 7.1 is unable to digest.
> > In my experience, MS-DOS 7.1 handles 64 kib clusters just fine. 128
> sectors
> > / cluster is possible and works perfectly well, even for FAT32 drives.
> > (This option allows one to format and use FAT16 drives up to 4 GiB in
> DOS).
>
>
>
>
> Question - Does booting on a 128 sectors/cluster FAT32 partition with
> MS-DOS 7.1 work for you?
>
>
> I can use FAT32 700 GB partition for data/files - but I cannot boot from
> same (using the auto-installed MS-DOS 7.1 from CD).
>

Perhaps a silly question, but....

Is the partition in-question marked as "active/bootable" ?

---
--
http://glennmcc.org/
Richard

03.01.2023, 04:37

@ glennmcc
 

WDe and GPT, booting DOS

Post reply

>
> Perhaps a silly question, but....
>
> Is the partition in-question marked as "active/bootable" ?



[image]



The status "A" was done for me by the MS-DOS 7.1 CD install program - so I "assume" that it is bootable (i.e., I did not use e.g. Windows or anything to force the partition to be active/bootable).


I do not know if the "A" status flag can be falsely set with 128 sectors/cluster FAT32.


Should I go to Windows (say) and toggle and reset to "Active" the FAT32 700 GB partition?
Richard

03.01.2023, 05:17

@ Richard
 

WDe and GPT, booting DOS

Post reply

I hope that the author of Trace203.com (Trace.com) will consider adding the following feature requests to Trace203....



1. indicate the status (e.g., "Active") of the drive



2. in BRIGHT RED (say) (non-blinking since blinking causes screen shot issue) indicate the partition-style.

Blank --> MBR (default)
"GPT" --> in bright red


Typically, the whole physical disk has all partitions the same partition-style (MBR or GPT only) - i.e., no perhaps hybrid partition-styles (combined MBR and GPT partitions).



3. The Operating System (e.g. MS-DOS 7.1, FreeDOS) that is currently running.



4. If BIOS set to Legacy, CSM(+UEFI), or (UEFI) - last option not a reality (yet).



5. If the drive is a RAMdrive (blank (default) = physical drive)


The reasons for the feature requests are that when I have a number of screen captures, it is nice to know these operating conditions - and TRACE is a very convenient (and concise) tool to apply to screen captures.
jadoxa

Homepage E-mail

Queensland, Australia,
04.01.2023, 01:02

@ Richard
 

WDe and GPT, booting DOS

Post reply

> I hope that the author of Trace203.com (Trace.com) will consider adding the
> following feature requests to Trace203....
I will not. Trace is a FAT file utility, which happens to display some drive info (since it's needed for the tracing). What you want is physical disk info, which would be a whole different utility (which I'm not going to write).
Japheth

Homepage

Germany (South),
03.01.2023, 09:14

@ Richard
 

WDe and GPT, booting DOS

Post reply

> Question - Does booting on a 128 sectors/cluster FAT32 partition with
> MS-DOS 7.1 work for you?

No.

One could do now further tests to see if smaller partitions will work with 128 sectors/cluster, but I don't think it's worth it.

---
MS-DOS forever!
Richard

16.01.2023, 02:50
(edited by Richard, 16.01.2023, 05:56)

@ Japheth
 

WDe and GPT, booting DOS

Post reply

(Sorry - Wanted to reply "to myself" but forum timeout after 4320 minutes)




Getting more practice with MSDOS71 FAT32 GPT boot install ...



Testing Partitions information for GPT FAT32 MSDOS71




Configured two 4TB drives as GPT style disc with MSDOS71 bootable on multiple GPT FAT32 partitions as follows (using Windows 10 22H2 x64 pro Disk Management to create all partitions and paid 3rd party app, where necessary, to ensure partitions are FAT32 rather than say exFAT)



drive #0 524287 MB MSDOS71 bootable FAT32 GPT and Mint 21.1 - in first part of first 2TB of 4TB drive.

drive #1 64, 128, 256, ... 262144, 524287 MB (all MSDOS71 bootable FAT32 GPT) partitions and Mint 21.1 - in the first part of first 2TB of 4TB drive.


[image]
It seems that the forum software CANNOT handle a very skinny .png file even though it is under the 75 KB limit
https://www.dropbox.com/s/zdb03dg76zrfjd2/Multi-GPT.PNG?dl=1



Resulting Mint 21.1 (grub 2.06) Menu for drive #1
[image]
Note: -
sda4 = 64 MB FAT32 GPT MSDOS71 bootable partition
sda5 = 128 MB ...
sda6 = 256 MB ...
sda7 = 512 MB ...
sda8 = 1024 MB ...
sda9 = 2048 MB ...
sda10 = 4096 MB ...
sda11 = 8192 MB ...
sda12 = 16384 MB ...
sda13 = 32768 MB ...
sda14 = 65536 MB ...
sda15 = 131072 MB ...
sda16 = 262144 MB ...
sda17 = 524287 MB ... NOT BOOTABLE refer disc #0 instead


Partition Management programs used here are Fdisk (FreeDOS), Fdisk (MS-DOS 71) and Ranish (current)


Summary

All Partition software used here do not seem to work for me (properly).

Volume labels are incorrectly referenced (mostly) - apparently. there are TWO locations relating to VOLUME LABELS. The volume labels used are the number of MB for the respective partitions.

Windows 10 app (HxD Hex editor) was used to verify the existence of two volume label locations.


The MS-DOS 71 version of Fdisk works (mostly) but the FreeDOS version does not correctly show partition size for FAT32 GPT.


It was not anticipated that Ranish would work for GPT - but tried it just for fun.

Preliminary Conclusion re MSDOS71 on FAT32 GPT - for any physical disk, the sum of ALL GPT FAT32 MSDOS71 bootable partitions cannot exceed (about) 524287 MB (512 GB). The minimum size, even if only one bootable partition, is 64 MB. As Japheth is already aware (I think), any one MSDOS71 GPT FAT32 bootable partition cannot, it seems, be able to interact with any other partition (e.g. to copy files) - a driver needs to be used.




The following screenshots are included to support my above claims - PLEASE EXIT THIS REPLY NOW - no new information follows





Note - the order of the two Fdisk screen captures is firstly FreeDOS then MS-DOS 7.1 versions


Disc #1



64 MB FAT 32 GPT MS-DOS 71

 Offset: 000  Sector: 260096       [Data]                      CHS: 16/48/33
 
 0000                                       00  02 01 7E 18     X MSDOS5.0   ~
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 F8 03 00            ?
 0020    00 00 02 00  C1 03 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 00 29 2C  7C 01 E8 4E  4F 20 4E 41  4D 45 20 20      ),|  NO NAME
 0050    20 20 46 41  54 33 32 20  20 20                         FAT32   3


 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 260096                      Last LBA: 391167
 Size: 64 MB                            Flags: 0
 Name: Basic data partition

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128 MB FAT 32 GPT MS-DOS 71

 Offset: 000  Sector: 393216       [Data]
 
 0000                                       00  02 02 3E 18     X MSDOS5.0   >
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 00 06 00            ?
 0020    00 00 04 00  E1 03 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 01 29 E9  14 35 EE 4E  4F 20 4E 41  4D 45 20 20      )  5 NO NAME
 0050    20 20 46 41  54 33 32 20  20 20                         FAT32   3

 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 393216                      Last LBA: 655359
 Size: 128 MB                           Flags: 0
 Name: Basic data partition
 

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256 MB FAT 32 GPT MS-DOS 71

 Offset: 000  Sector: 655360       [Data]
 
 0000                                       00  02 04 1E 18     X MSDOS5.0
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 00 0A 00            ?
 0020    00 00 08 00  F1 03 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 01 29 B1  D1 4B 94 4E  4F 20 4E 41  4D 45 20 20      )  K NO NAME
 0050    20 20 46 41  54 33 32 20  20 20                         FAT32   3

 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 655360                      Last LBA: 1179647
 Size: 256 MB                           Flags: 0
 Name: Basic data partition


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512 MB FAT 32 GPT MS-DOS 71

 Offset: 000  Sector: 1179648      [Data]
 
 0000                                       00  02 08 0E 18     X MSDOS5.0
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 00 12 00            ?
 0020    00 00 10 00  F9 03 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 01 29 C1  1C 72 D8 4E  4F 20 4E 41  4D 45 20 20      )  r NO NAME
 0050    20 20 46 41  54 33 32 20  20 20                         FAT32   3
 
 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 1179648                     Last LBA: 2228223
 Size: 512 MB                           Flags: 0
 Name: Basic data partition


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1024 MB FAT 32 GPT MS-DOS 71

 Offset: 000  Sector: 2228224      [Data]                      CHS: 138/178/41
 
 0000                                       00  02 08 0E 10     X MSDOS5.0
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 00 22 00            ?     "
 0020    00 00 20 00  F9 07 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 01 29 35  1D 90 04 4E  4F 20 4E 41  4D 45 20 20      )5   NO NAME
 0050    20 20 46 41  54 33 32 20  20 20                         FAT32   3

 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 2228224                     Last LBA: 4325375
 Size: 1024 MB                          Flags: 0
 Name: Basic data partition


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2048 MB FAT 32 GPT MS-DOS 71

 Offset: 000  Sector: 4325376      [Data]
 
 0000                                       00  02 08 1E 20     X MSDOS5.0
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 00 42 00            ?     B
 0020    00 00 40 00  F1 0F 00 00  00 00 00 00  02 00 00 00      @
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 01 29 B4  AC B6 C0 4E  4F 20 4E 41  4D 45 20 20      )    NO NAME
 0050    20 20 46 41  54 33 32 20  20 20                         FAT32   3

 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 4325376                     Last LBA: 8519679
 Size: 2048 MB                          Flags: 0
 Name: Basic data partition


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4096 MB FAT 32 GPT MS-DOS 71

 Offset: 000  Sector: 8519680      [Data]
 
 0000                                       00  02 08 2E 20     X MSDOS5.0   .
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 00 82 00            ?
 0020    00 00 80 00  E9 1F 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 01 29 34  E4 C8 FC 4E  4F 20 4E 41  4D 45 20 20      )4   NO NAME
 0050    20 20 46 41  54 33 32 20  20 20                         FAT32   3
 
 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 8519680                     Last LBA: 16908287
 Size: 4096 MB                          Flags: 0
 Name: Basic data partition


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8192 MB FAT 32 GPT MS-DOS 71

 Offset: 000  Sector: 16908288     [Data]                      CHS: 1052/125/34

 0000                                       00  02 10 16 20     X MSDOS5.0
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 00 02 01            ?
 0020    00 00 00 01  F5 1F 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 01 29 69  AF E3 F2 4E  4F 20 4E 41  4D 45 20 20      )i   NO NAME
 0050    20 20 46 41  54 33 32 20  20 20                         FAT32   3

 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 16908288                    Last LBA: 33685503
 Size: 8192 MB                          Flags: 0
 Name: Basic data partition


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16384 MB FAT 32 GPT MS-DOS 71

 Offset: 000  Sector: 33685504     [Data]
 
 0000                                       00  02 20 0A 20     X MSDOS5.0
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 00 02 02            ?
 0020    00 00 00 02  FB 1F 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 01 29 FA  A2 F8 68 4E  4F 20 4E 41  4D 45 20 20      )   hNO NAME
 0050    20 20 46 41  54 33 32 20  20 20                         FAT32   3

 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 33685504                    Last LBA: 67239935
 Size: 16384 MB                         Flags: 0
 Name: Basic data partition


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32768 MB FAT 32 GPT MS-DOS 71

 Offset: 000  Sector: 67239936     [Data]
 
 0000                                       00  02 40 04 20     X MSDOS5.0  @
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 00 02 04            ?
 0020    00 00 00 04  FE 1F 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 01 29 3E  7F 21 7A 4E  4F 20 4E 41  4D 45 20 20      )> !zNO NAME
 0050    20 20 46 41  54 33 32 20  20 20                         FAT32   3
 
 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 67239936                    Last LBA: 134348799
 Size: 32768 MB                         Flags: 0
 Name: Basic data partition


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65536 MB FAT 32 GPT MS-DOS 71

 Offset: 000  Sector: 134348800    [Data]
 
 0000                                       00  02 40 20 00     X PKWIN4.1  @
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 00 02 08            ?
 0020    FF FF FF 07  FC 3F 00 00  00 00 00 00  02 00 00 00         ?
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 00 29 98  11 41 0C 36  35 35 33 36  00 00 00 00      )  A 65536
 0050    00 00 46 41  54 33 32 20  20 20                         FAT32   3
 
 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 134348800                   Last LBA: 268566527
 Size: 65536 MB                         Flags: 0
 Name: Basic data partition


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131072 MB FAT 32 GPT MS-DOS 71

 Offset: 000  Sector: 268566528    [Data]

 0000                                       00  02 40 20 00     X PKWIN4.1  @
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 00 02 10            ?
 0020    00 00 00 10  F8 7F 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 00 29 DF  13 41 0C 31  33 31 30 37  32 00 00 00      )  A 131072
 0050    00 00 46 41  54 33 32 20  20 20                         FAT32   3

 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 268566528                   Last LBA: 537001983
 Size: 131072 MB                        Flags: 0
 Name: Basic data partition
/code]

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262144 MB FAT 32 GPT MS-DOS 71
[code]
 Offset: 000  Sector: 537001984    [Data]                      CHS: 33426/211/2

 0000                                       00  02 40 20 00     X PKWIN4.1  @
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 00 02 20            ?
 0020    00 00 00 20  F0 FF 00 00  00 00 00 00  02 00 00 00
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 00 29 A9  17 41 0C 32  36 32 31 34  34 00 00 00      )  A 262144
 0050    00 00 46 41  54 33 32 20  20 20                         FAT32   3
 
 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 537001984                   Last LBA: 1073872895
 Size: 262144 MB                        Flags: 0
 Name: Basic data partition


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524287 MB FAT 32 GPT MS-DOS 71 NOT BOOTABLE refer Disc #0 instead


 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 1073872896                  Last LBA: 2147612671
 Size: 524287 MB                        Flags: 0
 Name: Basic data partition
 
 
 
 
 F1-Help   F2-File   F3-Goto   F4-View   F5-Find   F6-Functions   F7-Save
Your program caused a divide overflow error.
If the problem persists, contact your program vendor.
 
C:\>


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Disc #0

524287 MB FAT 32 GPT MS-DOS 71

 Offset: 000  Sector: 67362816     [Data]                      CHS: 4193/36/4
 
 0000                                       00  02 40 20 00     X PKWIN4.1  @
 0010    02 00 00 00  00 F8 00 00  3F 00 FF 00  00 E0 03 04            ?
 0020    00 F8 FF 3F  E0 FF 01 00  00 00 00 00  02 00 00 00       ?
 0030    01 00 06 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    80 00 29 BF  18 83 0F 35  32 34 32 38  37 00 00 00      )    524287
 0050    00 00 46 41  54 33 32 20  20 20                         FAT32   3
 
 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 67362816                    Last LBA: 1141102591
 Size: 524287 MB                        Flags: 0
 Name: Basic data partition


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If I hold my breath - will M$ fix the issue of two locations in MS-DOS 7.1 for VOLUME LABEL (I claim) - as this is causing great confusion for me? :-)
Richard

08.12.2022, 17:22
(edited by Richard, 09.12.2022, 00:46)

@ Japheth
 

WDe and GPT, booting DOS

Post reply



 0120    66 09 C0 75  4E 66 A1 5C  7C 66 31 D2  66 F7 34 88    f  uNf \|f1 f 4
 0130    D1 31 D2 66  F7 74 04 3B  44 08 7D 37  FE C1 88 C5     1 f t ;D }7
 0140    30 C0 C1 E8  02 08 C1 88  D0 5A 88 C6  BB 00 70 8E    0        Z    p
 0150    C3 31 DB B8  01 02 CD 13  72 1E 8C C3  60 1E B9 00     1      r   `
 0160    01 8E DB 31  F6 BF 00 80  8E C6 FC F3  A5 1F 61 FF       1          a
 0170    26 5A 7C BE  8E 7D EB 03  BE 9D 7D E8  34 00 BE A2    &Z|  }    } 4
 0180    7D E8 2E 00  CD 18 EB FE  47 52 55 42  20 00 47 65    } .     GRUB  Ge
 0190    6F 6D 00 48  61 72 64 20  44 69 73 6B  00 52 65 61    om Hard Disk Rea
 01A0    64 00 20 45  72 72 6F 72  0D 0A 00 BB  01 00 B4 0E    d  Error
 01B0    CD 10 AC 3C  00 75 F4 C3  01 00 00 00  00 00 00 00       < u
 01C0    02 00 EE FF  FF FF 01 00  00 00 EB 66  54 57 00 00               fTW
 01D0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 55 AA                  U
 
 P Type             Boot Start-CHS   End-CHS     Start-LBA  Size       MB
 ------------------------------------------------------------------------------
 1 EE EFI           00   0/0/2       1023/255/63 1          1465149163 715405
 2 00 Unused        00   0/0/0       0/0/0       0          0          0
 3 00 Unused        00   0/0/0       0/0/0       0          0          0
 4 00 Unused        00   0/0/0       0/0/0       0          0          0
 
 
 F1-Save to File   F2-Restore from File   F3-Change Disk






GPT disk 1 ----------------------------------------------------------------------------------

Using WDE on the second-last attempt of the GPT DOS BOOT experiment, the following applies


(As I do not understand how to use WDE to transfer the MODIFIED MBR partition to the GPT disc, I simply used Windows app to CLONE same.)


Using WDE the modified DOS71 partition was saved as a file DOS71BSG.PAR (541,065,216 bytes) for future use.







<WDE04.txt disc 1 5/12 2:20am>

 Offset: 000  Sector: 0            [MBR]                       CHS: 0/0/1
 0000    EB 63 90 00  00 00 00 00  00 00 00 00  00 00 00 00     c
 0010    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0020    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0030    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0050    00 00 00 00  00 00 00 00  00 00 00 80  78 AD 26 02                x &
 0060    00 00 00 00  FF FA 90 90  F6 C2 80 74  05 F6 C2 70               t   p
 0070    74 02 B2 80  EA 79 7C 00  00 31 C0 8E  D8 8E D0 BC    t    y|  1
 0080    00 20 FB A0  64 7C 3C FF  74 02 88 C2  52 BB 17 04        d|< t   R
 0090    F6 07 03 74  06 BE 88 7D  E8 17 01 BE  05 7C B4 41       t   }     | A
 00A0    BB AA 55 CD  13 5A 52 72  3D 81 FB 55  AA 75 37 83      U  ZRr=  U u7
 00B0    E1 01 74 32  31 C0 89 44  04 40 88 44  FF 89 44 02      t21  D @ D  D
 00C0    C7 04 10 00  66 8B 1E 5C  7C 66 89 5C  08 66 8B 1E        f  \|f \ f
 00D0    60 7C 66 89  5C 0C C7 44  06 00 70 B4  42 CD 13 72    `|f \  D  p B  r
 00E0    05 BB 00 70  EB 76 B4 08  CD 13 73 0D  5A 84 D2 0F       p v    s Z
 00F0    83 D0 00 BE  93 7D E9 82  00 66 0F B6  C6 88 64 FF         }   f    d
 0100    40 66 89 44  04 0F B6 D1  C1 E2 02 88  E8 88 F4 40    @f D           @
 0110    89 44 08 0F  B6 C2 C0 E8  02 66 89 04  66 A1 60 7C     D       f  f `|
 0120    66 09 C0 75  4E 66 A1 5C  7C 66 31 D2  66 F7 34 88    f  uNf \|f1 f 4
 0130    D1 31 D2 66  F7 74 04 3B  44 08 7D 37  FE C1 88 C5     1 f t ;D }7
 0140    30 C0 C1 E8  02 08 C1 88  D0 5A 88 C6  BB 00 70 8E    0        Z    p
 0150    C3 31 DB B8  01 02 CD 13  72 1E 8C C3  60 1E B9 00     1      r   `
 0160    01 8E DB 31  F6 BF 00 80  8E C6 FC F3  A5 1F 61 FF       1          a
 0170    26 5A 7C BE  8E 7D EB 03  BE 9D 7D E8  34 00 BE A2    &Z|  }    } 4
 0180    7D E8 2E 00  CD 18 EB FE  47 52 55 42  20 00 47 65    } .     GRUB  Ge
 0190    6F 6D 00 48  61 72 64 20  44 69 73 6B  00 52 65 61    om Hard Disk Rea
 01A0    64 00 20 45  72 72 6F 72  0D 0A 00 BB  01 00 B4 0E    d  Error
 01B0    CD 10 AC 3C  00 75 F4 C3  01 00 00 00  00 00 00 00       < u
 01C0    02 00 EE FF  FF FF 01 00  00 00 EB 66  54 57 00 00               fTW
 01D0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 55 AA                  U
 
 P Type             Boot Start-CHS   End-CHS     Start-LBA  Size       MB
 ------------------------------------------------------------------------------
 1 EE EFI           00   0/0/2       1023/255/63 1          1465149163 715405
 2 00 Unused        00   0/0/0       0/0/0       0          0          0
 3 00 Unused        00   0/0/0       0/0/0       0          0          0
 4 00 Unused        00   0/0/0       0/0/0       0          0          0
 
 
 F1-Help   F2-File   F3-Goto   F4-View   F5-Find   F6-Functions   F7-Save





<WDE06.txt 5/12 2:21am>

 Offset: 000  Sector: 1            [GPT Hdr]                   CHS: 0/0/2
 0000    45 46 49 20  50 41 52 54  00 00 01 00  5C 00 00 00    EFI PART    \
 0010    58 EB 3C 0A  00 00 00 00  01 00 00 00  00 00 00 00    X <
 0020    EB 66 54 57  00 00 00 00  22 00 00 00  00 00 00 00     fTW    "
 0030    CA 66 54 57  00 00 00 00  30 25 A2 B2  98 C9 CC 44     fTW    0%     D
 0040    93 FF 02 B9  25 AE 33 DC  02 00 00 00  00 00 00 00        % 3
 0050    80 00 00 00  80 00 00 00  0E 74 B1 4E  00 00 00 00             t N
 0060    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0070    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0080    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0090    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00A0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00B0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00C0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00D0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0100    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0110    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0120    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0130    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0140    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0150    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0160    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0170    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0180    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0190    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01A0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01B0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01C0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01D0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 
 Signature:            EFI PART         Size GPT Header:       92
 CRC (disk):           0A3CEB58         CRC (calculated):      0a3ceb58
 Current LBA:          1                Backup LBA:            1465149163
 First LBA:            34               Last LBA:              1465149130
 Start GPT:            2                Entries GPT:           128
 Size GPT Entry:       128              CRC GPT Entries:       4EB1740E
 
 
 F1-Help   F2-File   F3-Goto   F4-View   F5-Find   F6-Functions   F7-Save





<WDE07.txt 5/12 2:21am>

 Offset: 000  Sector: 2            [GPT]                       CHS: 0/0/3
 0000    16 E3 C9 E3  5C 0B B8 4D  81 7D F9 2D  F0 02 15 AE        \  M } -
 0010    EF 8F 6D D6  5C B8 CF 45  B1 06 99 C8  A7 1C 03 7C      m \  E       |
 0020    22 00 00 00  00 00 00 00  FF 7F 00 00  00 00 00 00    "
 0030    00 00 00 00  00 00 00 00  4D 00 69 00  63 00 72 00            M i c r
 0040    6F 00 73 00  6F 00 66 00  74 00 20 00  72 00 65 00    o s o f t   r e
 0050    73 00 65 00  72 00 76 00  65 00 64 00  20 00 70 00    s e r v e d   p
 0060    61 00 72 00  74 00 69 00  74 00 69 00  6F 00 6E 00    a r t i t i o n
 0070    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0080    A2 A0 D0 EB  E5 B9 33 44  87 C0 68 B6  B7 26 99 C7          3D  h  &
 0090    48 26 7F 63  2D 71 ED 11  89 71 28 B2  BD F0 65 5D    H& c-q   q(   e]
 00A0    00 80 00 00  00 00 00 00  FF 9F 10 00  00 00 00 00
 00B0    00 00 00 00  00 00 00 00  42 00 61 00  73 00 69 00            B a s i
 00C0    63 00 20 00  64 00 61 00  74 00 61 00  20 00 70 00    c   d a t a   p
 00D0    61 00 72 00  74 00 69 00  74 00 69 00  6F 00 6E 00    a r t i t i o n
 00E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0100    28 73 2A C1  1F F8 D2 11  BA 4B 00 A0  C9 3E C9 3B    (s*      K   > ;
 0110    96 85 1F 07  D1 4A 5B 46  BD 4B 17 D2  A2 A6 4E 6F         J[F K    No
 0120    00 E0 10 00  00 00 00 00  FF FF 13 00  00 00 00 00
 0130    00 00 00 00  00 00 00 00  45 00 46 00  49 00 20 00            E F I
 0140    53 00 79 00  73 00 74 00  65 00 6D 00  20 00 50 00    S y s t e m   P
 0150    61 00 72 00  74 00 69 00  74 00 69 00  6F 00 6E 00    a r t i t i o n
 0160    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0170    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0180    AF 3D C6 0F  83 84 72 47  8E 79 3D 69  D8 47 7D E4     =    rG y=i G}
 0190    90 B5 96 5F  6A DD 49 4A  A6 25 AA E9  C1 3A DD 84       _j IJ %   :
 01A0    00 00 14 00  00 00 00 00  FF 3F 1B 04  00 00 00 00             ?
 01B0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01C0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01D0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 
 Type: {e3c9e316-0b5c-4db8-817d-f92df00215ae}
 First LBA: 34                          Last LBA: 32767
 Size: 15 MB                            Flags: 0
 Name: Microsoft reserved partition
 
 
 
 
 F1-Help   F2-File   F3-Goto   F4-View   F5-Find   F6-Functions   F7-Save










<WDE11.txt 5/12 2:22am>

 Offset: 000  Sector: 3            [GPT]                       CHS: 0/0/4
 0000    A2 A0 D0 EB  E5 B9 33 44  87 C0 68 B6  B7 26 99 C7          3D  h  &
 0010    06 06 1D B3  96 6C C5 43  8D 98 58 4D  05 03 B4 05         l C  XM
 0020    00 40 1B 04  00 00 00 00  FF 57 54 57  00 00 00 00     @       WTW
 0030    00 00 00 00  00 00 00 00  42 00 61 00  73 00 69 00            B a s i
 0040    63 00 20 00  64 00 61 00  74 00 61 00  20 00 70 00    c   d a t a   p
 0050    61 00 72 00  74 00 69 00  74 00 69 00  6F 00 6E 00    a r t i t i o n
 0060    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0070    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0080    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0090    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00A0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00B0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00C0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00D0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0100    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0110    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0120    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0130    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0140    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0150    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0160    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0170    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0180    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0190    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01A0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01B0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01C0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01D0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 
 Type: {ebd0a0a2-b9e5-4433-87c0-68b6b72699c7}
 First LBA: 68894720                    Last LBA: 1465145343
 Size: 681763 MB                        Flags: 0
 Name: Basic data partition
 
 
 
 
 F1-Auto  F2-MBR  F3-Boot Sector  F4-Fat12  F5-Fat16  F6-Fat32  F7-Directory





<WDE12.txt 5/12 2:23am>

 Offset: 000  Sector: 4            [GPT]                       CHS: 0/0/5
 0000    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0010    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0020    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0030    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0050    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0060    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0070    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0080    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0090    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00A0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00B0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00C0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00D0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 00F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0100    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0110    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0120    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0130    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0140    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0150    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0160    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0170    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0180    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0190    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01A0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01B0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01C0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01D0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 
 Type: {00000000-0000-0000-0000-000000000000}
 First LBA: 0                           Last LBA: 0
 Size: 0 MB                             Flags: 0
 
 
 
 
 
 F1-Auto  F2-MBR  F3-Boot Sector  F4-Fat12  F5-Fat16  F6-Fat32  F7-Directory








<WDE14.txt 5/12 2:23am>

 Offset: 000  Sector: 0            [MBR]                       CHS: 0/0/1
 0000    EB 63 90 00  00 00 00 00  00 00 00 00  00 00 00 00     c
 0010    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0020    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0030    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0050    00 00 00 00  00 00 00 00  00 00 00 80  78 AD 26 02                x &
 0060    00 00 00 00  FF FA 90 90  F6 C2 80 74  05 F6 C2 70               t   p
 0070    74 02 B2 80  EA 79 7C 00  00 31 C0 8E  D8 8E D0 BC    t    y|  1
 0080    00 20 FB A0  64 7C 3C FF  74 02 88 C2  52 BB 17 04        d|< t   R
 0090    F6 07 03 74  06 BE 88 7D  E8 17 01 BE  05 7C B4 41       t   }     | A
 00A0    BB AA 55 CD  13 5A 52 72  3D 81 FB 55  AA 75 37 83      U  ZRr=  U u7
 00B0    E1 01 74 32  31 C0 89 44  04 40 88 44  FF 89 44 02      t21  D @ D  D
 00C0    C7 04 10 00  66 8B 1E 5C  7C 66 89 5C  08 66 8B 1E        f  \|f \ f
 00D0    60 7C 66 89  5C 0C C7 44  06 00 70 B4  42 CD 13 72    `|f \  D  p B  r
 00E0    05 BB 00 70  EB 76 B4 08  CD 13 73 0D  5A 84 D2 0F       p v    s Z
 00F0    83 D0 00 BE  93 7D E9 82  00 66 0F B6  C6 88 64 FF         }   f    d
 0100    40 66 89 44  04 0F B6 D1  C1 E2 02 88  E8 88 F4 40    @f D           @
 0110    89 44 08 0F  B6 C2 C0 E8  02 66 89 04  66 A1 60 7C     D       f  f `|
 0120    66 09 C0 75  4E 66 A1 5C  7C 66 31 D2  66 F7 34 88    f  uNf \|f1 f 4
 0130    D1 31 D2 66  F7 74 04 3B  44 08 7D 37  FE C1 88 C5     1 f t ;D }7
 0140    30 C0 C1 E8  02 08 C1 88  D0 5A 88 C6  BB 00 70 8E    0        Z    p
 0150    C3 31 DB B8  01 02 CD 13  72 1E 8C C3  60 1E B9 00     1      r   `
 0160    01 8E DB 31  F6 BF 00 80  8E C6 FC F3  A5 1F 61 FF       1          a
 0170    26 5A 7C BE  8E 7D EB 03  BE 9D 7D E8  34 00 BE A2    &Z|  }    } 4
 0180    7D E8 2E 00  CD 18 EB FE  47 52 55 42  20 00 47 65    } .     GRUB  Ge
 0190    6F 6D 00 48  61 72 64 20  44 69 73 6B  00 52 65 61    om Hard Disk Rea
 01A0    64 00 20 45  72 72 6F 72  0D 0A 00 BB  01 00 B4 0E    d  Error
 01B0    CD 10 AC 3C  00 75 F4 C3  01 00 00 00  00 00 00 00       < u
 01C0    02 00 EE FF  FF FF 01 00  00 00 EB 66  54 57 00 00               fTW
 01D0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 55 AA                  U
 
 Bytes per Sector:     0                Sectors per Cluster:   0
 Reserved Sectors:     0                FATs:                  0
 Maximum Root Entries: 0                Media Descriptor:      0
 Sectors per Fat:      0                Partition Start:       0
 Sectors in Partition: 0                Hard Disk Number:      0
 Root Start Cluster:   0                FSInfo Sector Number:  0
 Backup B.S. Location: 0                Signature:             AA55
 
 F1-Auto  F2-MBR  F3-Boot Sector  F4-Fat12  F5-Fat16  F6-Fat32  F7-Directory
Richard

08.12.2022, 17:24
(edited by Richard, 09.12.2022, 00:40)

@ Japheth
 

WDe and GPT, booting DOS

Post reply

<WDE15.txt 5/12 2:24am>

 Offset: 000  Sector: 0            [MBR]                       CHS: 0/0/1
 0000    EB 63 90 00  00 00 00 00  00 00 00 00  00 00 00 00     c
 0010    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0020    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0030    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0050    00 00 00 00  00 00 00 00  00 00 00 80  78 AD 26 02                x &
 0060    00 00 00 00  FF FA 90 90  F6 C2 80 74  05 F6 C2 70               t   p
 0070    74 02 B2 80  EA 79 7C 00  00 31 C0 8E  D8 8E D0 BC    t    y|  1
 0080    00 20 FB A0  64 7C 3C FF  74 02 88 C2  52 BB 17 04        d|< t   R
 0090    F6 07 03 74  06 BE 88 7D  E8 17 01 BE  05 7C B4 41       t   }     | A
 00A0    BB AA 55 CD  13 5A 52 72  3D 81 FB 55  AA 75 37 83      U  ZRr=  U u7
 00B0    E1 01 74 32  31 C0 89 44  04 40 88 44  FF 89 44 02      t21  D @ D  D
 00C0    C7 04 10 00  66 8B 1E 5C  7C 66 89 5C  08 66 8B 1E        f  \|f \ f
 00D0    60 7C 66 89  5C 0C C7 44  06 00 70 B4  42 CD 13 72    `|f \  D  p B  r
 00E0    05 BB 00 70  EB 76 B4 08  CD 13 73 0D  5A 84 D2 0F       p v    s Z
 00F0    83 D0 00 BE  93 7D E9 82  00 66 0F B6  C6 88 64 FF         }   f    d
 0100    40 66 89 44  04 0F B6 D1  C1 E2 02 88  E8 88 F4 40    @f D           @
 0110    89 44 08 0F  B6 C2 C0 E8  02 66 89 04  66 A1 60 7C     D       f  f `|
 0120    66 09 C0 75  4E 66 A1 5C  7C 66 31 D2  66 F7 34 88    f  uNf \|f1 f 4
 0130    D1 31 D2 66  F7 74 04 3B  44 08 7D 37  FE C1 88 C5     1 f t ;D }7
 0140    30 C0 C1 E8  02 08 C1 88  D0 5A 88 C6  BB 00 70 8E    0        Z    p
 0150    C3 31 DB B8  01 02 CD 13  72 1E 8C C3  60 1E B9 00     1      r   `
 0160    01 8E DB 31  F6 BF 00 80  8E C6 FC F3  A5 1F 61 FF       1          a
 0170    26 5A 7C BE  8E 7D EB 03  BE 9D 7D E8  34 00 BE A2    &Z|  }    } 4
 0180    7D E8 2E 00  CD 18 EB FE  47 52 55 42  20 00 47 65    } .     GRUB  Ge
 0190    6F 6D 00 48  61 72 64 20  44 69 73 6B  00 52 65 61    om Hard Disk Rea
 01A0    64 00 20 45  72 72 6F 72  0D 0A 00 BB  01 00 B4 0E    d  Error
 01B0    CD 10 AC 3C  00 75 F4 C3  01 00 00 00  00 00 00 00       < u
 01C0    02 00 EE FF  FF FF 01 00  00 00 EB 66  54 57 00 00               fTW
 01D0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 55 AA                  U
 
    09063EB ------- ------- ------- ------- ------- ------- ------- -------
    ------- ------- ------- ------- ------- ------- ------- ------- -------
    ------- ------- ------- ------- ------- ------- ------- ------- -------
    ------- ------- ------- ------- ------- ------- ------- ------- -------
    ------- ------- ------- ------- ------- ------- ------- ------- -------
    ------- ------- ------- ------- ------- ------- ------- ------- -------
    ------- ------- ------- ------- ------- ------- ------- ------- -------
 
 F1-Auto  F2-MBR  F3-Boot Sector  F4-Fat12  F5-Fat16  F6-Fat32  F7-Directory



<WDE16.txt 5/12 2:24am>

 Offset: 000  Sector: 0            [MBR]                       CHS: 0/0/1
 0000    EB 63 90 00  00 00 00 00  00 00 00 00  00 00 00 00     c
 0010    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0020    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0030    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0040    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 0050    00 00 00 00  00 00 00 00  00 00 00 80  78 AD 26 02                x &
 0060    00 00 00 00  FF FA 90 90  F6 C2 80 74  05 F6 C2 70               t   p
 0070    74 02 B2 80  EA 79 7C 00  00 31 C0 8E  D8 8E D0 BC    t    y|  1
 0080    00 20 FB A0  64 7C 3C FF  74 02 88 C2  52 BB 17 04        d|< t   R
 0090    F6 07 03 74  06 BE 88 7D  E8 17 01 BE  05 7C B4 41       t   }     | A
 00A0    BB AA 55 CD  13 5A 52 72  3D 81 FB 55  AA 75 37 83      U  ZRr=  U u7
 00B0    E1 01 74 32  31 C0 89 44  04 40 88 44  FF 89 44 02      t21  D @ D  D
 00C0    C7 04 10 00  66 8B 1E 5C  7C 66 89 5C  08 66 8B 1E        f  \|f \ f
 00D0    60 7C 66 89  5C 0C C7 44  06 00 70 B4  42 CD 13 72    `|f \  D  p B  r
 00E0    05 BB 00 70  EB 76 B4 08  CD 13 73 0D  5A 84 D2 0F       p v    s Z
 00F0    83 D0 00 BE  93 7D E9 82  00 66 0F B6  C6 88 64 FF         }   f    d
 0100    40 66 89 44  04 0F B6 D1  C1 E2 02 88  E8 88 F4 40    @f D           @
 0110    89 44 08 0F  B6 C2 C0 E8  02 66 89 04  66 A1 60 7C     D       f  f `|
 0120    66 09 C0 75  4E 66 A1 5C  7C 66 31 D2  66 F7 34 88    f  uNf \|f1 f 4
 0130    D1 31 D2 66  F7 74 04 3B  44 08 7D 37  FE C1 88 C5     1 f t ;D }7
 0140    30 C0 C1 E8  02 08 C1 88  D0 5A 88 C6  BB 00 70 8E    0        Z    p
 0150    C3 31 DB B8  01 02 CD 13  72 1E 8C C3  60 1E B9 00     1      r   `
 0160    01 8E DB 31  F6 BF 00 80  8E C6 FC F3  A5 1F 61 FF       1          a
 0170    26 5A 7C BE  8E 7D EB 03  BE 9D 7D E8  34 00 BE A2    &Z|  }    } 4
 0180    7D E8 2E 00  CD 18 EB FE  47 52 55 42  20 00 47 65    } .     GRUB  Ge
 0190    6F 6D 00 48  61 72 64 20  44 69 73 6B  00 52 65 61    om Hard Disk Rea
 01A0    64 00 20 45  72 72 6F 72  0D 0A 00 BB  01 00 B4 0E    d  Error
 01B0    CD 10 AC 3C  00 75 F4 C3  01 00 00 00  00 00 00 00       < u
 01C0    02 00 EE FF  FF FF 01 00  00 00 EB 66  54 57 00 00               fTW
 01D0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01E0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00
 01F0    00 00 00 00  00 00 00 00  00 00 00 00  00 00 55 AA                  U
 
     Name:  c
  Created: 01-01-1980 00:00:00.0        Attributes: ------
 Accessed: 01-01-1980                      Cluster: 0000
 Modified: 01-01-1980 00:00:00                Size: 0
 
 
 
 
 F1-Auto  F2-MBR  F3-Boot Sector  F4-Fat12  F5-Fat16  F6-Fat32  F7-Directory





COMPARISONS

<Clone vs DOS71BSG.BIN(original)>
[image]


HIGH-RESOLUTION
https://www.dropbox.com/s/7xe464nu2b7sibk/CLONE%20vs%20DOS71BSG.BIN%28original%29.PNG?dl=1






<INITIAL BOOT-reserved vs Modified BOOT-reserved>

HIGH-RESOLUTION
https://www.dropbox.com/s/gr79nyzo3ygj1c3/INITAL%2...ved%20%20vs%20Modified%20BOOT-reserved.PNG?dl=1










GRUB setup

Using the CLONED modified partiton (Windows placed onto the GPT style disc)

LINUX MINT 21 was installed - which for some reason was not reproducable.
Out of about a dozen attempts to install MINT - only 2 instances had the option
"Install Linux Mint alongside MS-DOS 5.x/6.x/Win3.1"
but on both occassions the MINT install "locked up".
Finally, via another way - MINT was manually installed -
but sudo update-grub FAILED to add the MSDOS71 to the menu.



On running the GPT style disc (on 4 different computers),
get the error

error:file /boot/grub/i386-pc/normal.mod not found
Entering rescue mode ...
grub rescue>





IMPROVEMENTS TO WDE

- show drive (e.g. 0, 1, C, D ...)

- show last few keystrokes to get to the current screen (e.g. "F6 FAT32")
RayeR

Homepage

CZ,
15.12.2022, 19:49

@ tom
 

WDe and GPT, booting DOS

Post reply

> did you re-invent "Hybrid GPT" by writing a MBR into the boot sector?
I'm also curious why not to go this way. AFAIK GPT can have a "protective" MBR that does nothing useful just stops old disk tools to not screw the data as they don't understand GPT. By GPT-aware OSes and tools the MBR part should be ignored so I don't see reason why the MBR cannot be old good functional one that can load other boot sector within 2TB limit. Then any DOS should not complain if it found MBR on right place. Am I wrong?

---
DOS gives me freedom to unlimited HW access.
tom

Homepage

Germany (West),
15.12.2022, 20:14
(edited by tom, 15.12.2022, 21:31)

@ RayeR
 

WDe and GPT, booting DOS

Post reply

> > did you re-invent "Hybrid GPT" by writing a MBR into the boot sector?
>
> I'm also curious why not to go this way. AFAIK GPT can have a "protective"
> MBR that does nothing useful just stops old disk tools to not screw the
> data as they don't understand GPT. By GPT-aware OSes and tools the MBR part
> should be ignored so I don't see reason why the MBR cannot be old good
> functional one that can load other boot sector within 2TB limit. Then any
> DOS should not complain if it found MBR on right place. Am I wrong?
you are probably right.
the problem here is this 'probably'.

a "Hybrid GPT" is probably way more 'idiot proof' than Japhets 'you have to know every boot sector byte by its first name' method.

replacing a protective MBR (meaning "nothing to be seen here") with something like "a couple of small partitions, one 100GB FAT32 partition, then more of "nothing to be seen here") shouldn't result in problems.
tom

Homepage

Germany (West),
24.10.2022, 18:15

@ Japheth
 

WDe and GPT, booting DOS

Post reply

> And - does FreeDOS or DR-DOS behave better?
when booted from floppy,
www.drivesnapshot.de/download/kernel.sys should even show existing FAT/FAT32 partitions if they are below 2TB.

there is also a realistic chance that it works after being loaded by GRUB

Update 2023-01-04 by user 'rr': Fixed download link by adding http://
Zyzzle

25.10.2022, 02:55

@ tom
 

WDe and GPT, booting DOS

Post reply

> > And - does FreeDOS or DR-DOS behave better?
>
> when booted from floppy,
> www.drivesnapshot.de/download/kernel.sys
> should even show existing FAT/FAT32 partitions if they are below 2TB.
>
> there is also a realistic chance that it works after being loaded by GRUB
How about booting from a USB memory stick (formatted in FAT32, and with a BIOS that supports USB booting) instead of floppy? Assuming the FreeDOS io.sys is present, I think this should work, but I couldn't get FreeDOS to see GPT-partitioned drives via this method, either. FAT32 partitions showed up OK.
tom

Homepage

Germany (West),
25.10.2022, 13:39

@ Zyzzle
 

WDe and GPT, booting DOS

Post reply

> > > And - does FreeDOS or DR-DOS behave better?
> >
> > when booted from floppy,
> >
> www.drivesnapshot.de/download/kernel.sys
> > should even show existing FAT/FAT32 partitions if they are below 2TB.
> >
> > there is also a realistic chance that it works after being loaded by
> GRUB
>
> How about booting from a USB memory stick (formatted in FAT32, and with a
> BIOS that supports USB booting) instead of floppy?
 this should work identically.

> Assuming the FreeDOS io.sys is present,
 there is no such thing

> I think this should work, but I couldn't get FreeDOS to
> see GPT-partitioned drives via this method, either. FAT32 partitions showed
> up OK.
 you are not clear enough (for me) about what happens, and what not.

the kernel above intends to mount "Microsoft basic data " partitions, but don't touch EFI, Windows RE and other stuff (which would be trivial to change).

thus FAT32/FAT16 partitions would show up, but nothing else.

if your machine behaves differently, how exactly?

is this a virtual machine I could download?
tom

Homepage

Germany (West),
03.01.2023, 17:14

@ tom
 

WDe and GPT, booting DOS

Post reply

as was mentioned earlier

> > And - does FreeDOS or DR-DOS behave better?
>
> when booted from floppy,
> www.drivesnapshot.de/download/kernel.sys
> should even show existing FAT/FAT32 partitions if they are below 2TB.
>
> there is also a realistic chance that it works after being loaded by GRUB
this is a special freedos kernel that should detect GPT *data* partitions.

Update 2023-01-04 by user 'rr': Fixed download link by adding http://
Richard

03.01.2023, 17:44

@ tom
 

WDe and GPT, booting DOS

Post reply

> as was mentioned earlier
>
> > > And - does FreeDOS or DR-DOS behave better?
> >
> > when booted from floppy,
> >
> www.drivesnapshot.de/download/kernel.sys
> > should even show existing FAT/FAT32 partitions if they are below 2TB.
> >
> > there is also a realistic chance that it works after being loaded by
> GRUB
>
> this is a special freedos kernel that should detect GPT *data* partitions.



When I tried the link mentioned above, I got this

[image]


Any other link I could try?
fritz.mueller

Homepage

Munich, Germany,
03.01.2023, 18:17

@ Richard
 

WDe and GPT, booting DOS

Post reply

HI Richard,
Hi Richard,
guess what is wrong here:

https://www.bttr-software.de/forum/www.drivesnapshot.de/download/kernel.sys
Willi


> > as was mentioned earlier
> >
> > > > And - does FreeDOS or DR-DOS behave better?
> > >
> > > when booted from floppy,
> > >
> >
> www.drivesnapshot.de/download/kernel.sys
> > > should even show existing FAT/FAT32 partitions if they are below 2TB.
> > >
> > > there is also a realistic chance that it works after being loaded by
> > GRUB
> >
> > this is a special freedos kernel that should detect GPT *data*
> partitions.
>
>
>
>
> When I tried the link mentioned above, I got this
>
> [image]
>
>
> Any other link I could try?
Richard

03.01.2023, 18:28

@ fritz.mueller
 

WDe and GPT, booting DOS

Post reply

Have downloaded KERNEL.sys (45,826 bytes) just now - achieved this by simply pasting the URL into the Microsoft EDGE browser (very top field).


Do not understand why clicking on the link did not work though (but it does not matter since I have the KERNEL.SYS file now).


Now to try to use the file...
glennmcc

Homepage E-mail

North Jackson, Ohio (USA),
03.01.2023, 22:10

@ Richard
 

WDe and GPT, booting DOS

Post reply

> Have downloaded KERNEL.sys (45,826 bytes) just now - achieved this by
> simply pasting the URL into the Microsoft EDGE browser (very top field).
>
>
> Do not understand why clicking on the link did not work though (but it does
> not matter since I have the KERNEL.SYS file now).
>
>
> Now to try to use the file...
The link _should_ be... http://www.drivesnapshot.de/download/kernel.sys

---
--
http://glennmcc.org/
glennmcc

Homepage E-mail

North Jackson, Ohio (USA),
24.10.2022, 19:09

@ Japheth
 

WDe and GPT, booting DOS

Post reply

> Hello,
>
> recently I added support for GPT to WDe ( no binary available yet ).
>
> I tried to boot MS-DOS 7.1 from a GPT-partitioned disk ( via GRUB ), but
> that failed. Elaborating the problem one can "see" that the boot sector(s)
> of the FAT32 partition run correctly, IO.SYS is found and some sectors of
> it are loaded at the correct address, but after IO.SYS has taken over, the
> boot process stops.
>
> Is there a known solution to this little problem?
>
> And - does FreeDOS or DR-DOS behave better?
>
>
>
>
> P.S: Please don't ask why I would want to do such things!
No need to ask... the answer is the same as was this...

https://www.linuxquestions.org/questions/slackware...-it-%2Acould%2A-be-done-4175709646/#post6339673

;-)

---
--
http://glennmcc.org/
rr

Homepage E-mail

Berlin, Germany,
24.10.2022, 20:19

@ Japheth
 

WDe and GPT, booting DOS

Post reply

> I tried to boot MS-DOS 7.1 from a GPT-partitioned disk ( via GRUB ), but
> that failed. Elaborating the problem one can "see" that the boot sector(s)
> of the FAT32 partition run correctly, IO.SYS is found and some sectors of
> it are loaded at the correct address, but after IO.SYS has taken over, the
> boot process stops.
>
> Is there a known solution to this little problem?
>
> And - does FreeDOS or DR-DOS behave better?
I moved your post to the "Users" category, because your questions are not a "How To" guide. :-D

---
Forum admin
Japheth

Homepage

Germany (South),
25.10.2022, 05:14

@ rr
 

WDe and GPT, booting DOS

Post reply

> I moved your post to the "Users" category, because your questions are not a
> "How To" guide. :-D
Perhaps that's a bit hasty. You can't know yet how this thread is evolving. If there are smart and intelligent replies (:-D) coming ... it might evolve to a "de facto how-to".

---
MS-DOS forever!
Japheth

Homepage

Germany (South),
14.11.2022, 10:35

@ Japheth
 

WDe v1.0

Post reply

> recently I added support for GPT to WDe ( no binary available yet ).
I uploaded a binary - it's v1.0.

https://github.com/Baron-von-Riedesel/WDe

---
MS-DOS forever!
boeckmann

Aachen, Germany,
14.11.2022, 22:00

@ Japheth
 

WDe v1.0

Post reply

> > recently I added support for GPT to WDe ( no binary available yet ).
>
> I uploaded a binary - it's v1.0.
>
> https://github.com/Baron-von-Riedesel/WDe
Nice tool :-) Already used it to debug some boot sector related error.
Zyzzle

15.11.2022, 02:38

@ Japheth
 

WDe v1.0

Post reply

> > recently I added support for GPT to WDe ( no binary available yet ).
>
> I uploaded a binary - it's v1.0.
>
> https://github.com/Baron-von-Riedesel/WDe
 Fabulous! One of the most useful tools out there. Really thankful for your work in making WDe so useful and great.
Japheth

Homepage

Germany (South),
15.11.2022, 20:10

@ Zyzzle
 

WDe v1.0

Post reply

> > > recently I added support for GPT to WDe ( no binary available yet ).
> >
> > I uploaded a binary - it's v1.0.
> >
> > https://github.com/Baron-von-Riedesel/WDe
> Fabulous! One of the most useful tools out there. Really thankful for your
> work in making WDe so useful and great.
Thanks! IMO WDe always was an undervalued little gem - of course now even more than 18 years ago ... :-D

---
MS-DOS forever!
RayeR

Homepage

CZ,
15.12.2022, 19:41

@ Japheth
 

WDe v1.0

Post reply

I use Norton Disk Editor from Norton Utilities pack (newer version supports LBA) for messing with disk data, I'll have a look what's new in WD...

---
DOS gives me freedom to unlimited HW access.
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