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RayeR

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CZ,
08.11.2008, 17:48
 

DOS on Compaq EVO T20 thin client - possible? (Developers)

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I just got Compaq EVO T20 thin client (based on AMD Geode 300MHz + 16MB flashdisk + 32MB RAM) and I'm trying to run FreeDOS on it.
I know how to modify and flash firmware, it contains HDD image which is then probably emulated as normal HDD by BIOS. Original OS on the image was Win NT embedded on NTFS. I made a new hdd image and put freedos on it using bochs - it boots OK. Then I injected it to firmware but it doesn't boot :(
Only message "FreeDOS" is displayed and it hangs. This seems to hang at very beginning of bootsector exec. I patched boot drive at offset 24h to 80h but didn't helped, any idea?

btw on T20 is possible to run patched GRUB for loading Linux from USB flash so I would expect DOS should run also there...

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

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Wroclaw, Poland,
08.11.2008, 18:32

@ RayeR
 

DOS on Compaq EVO T20 thin client - possible?

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Are you sure that the HDD image is partitioned and formatted correctly?

Maybe there is a problem with either LBA or CHS in the INT 13h emulation services? There should be suitable options in SYS to deal with this kind of problems.

Have you tried some other DOS version?

Can you boot (Free)DOS from a USB memory stick or a USB FDD/HDD?
RayeR

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CZ,
09.11.2008, 00:37

@ mht
 

DOS on Compaq EVO T20 thin client - possible?

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> Are you sure that the HDD image is partitioned and formatted correctly?
Not 100%. The only one indicia is the original NTFS bootsector which says that HDD CHS parameters are: 208 heads, 56 sectors/track, 8 cylinders (quite odd but it is suited for the FlashROM size). Here is the orig BS dump:

[image]

Another non-strandard thing is a fact that MBR (and partition) is ignored at all! I can zero it and booting is not affected. BIOS simply reads the 2nd sector, expecting it is bootsector on 1st primary active partition. Of course I did some binary moves after creating my hdd image to match this. In BOCHS it boots properly.

> Maybe there is a problem with either LBA or CHS in the INT 13h emulation
> services? There should be suitable options in SYS to deal with this kind
> of problems.
>
> Have you tried some other DOS version?
FreeDOS hangs in very beginning stage displaying just "FreeDOS" (it should display "FreeDOS" "FAT" "KERNEL" "GO!". I tried also MS-DOS 6.22 and 7.x and they seems to get somewhere futher - end with "Non-System disk or disk error" so it seems did not located system files (but in BOCHS yes). Finally I used bootprep a nd copy NT loader files (ntdetect, ntldr, boot.ini) and it works, bootmenu appeared and finished with missing hal.dll (of course it was not there).

Here is my experimental hdd image with NT loader and dos bootsector image trying to be loaded with NT loader. If someone would check it.

> Can you boot (Free)DOS from a USB memory stick or a USB FDD/HDD?
No this doesn't provide any USB legacy support. So I have to rely on USB mass storage and HID drivers.

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

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CZ,
09.11.2008, 13:09

@ RayeR
 

DOS on Compaq EVO T20 thin client - possible?

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> Here is my experimental hdd image
> with NT loader and dos bootsector image trying to be loaded with NT
> loader. If someone would check it.

I found a strange problem in BOCHS with HDD access. When I copied more files from floppy to hdd image it hangs. Even ndd/scandisk hangs at 2% reading sector 969. It seems that I cannot write/read behind this sector. Maybe a BOCHS bug? Interestning that this number is not on track/head boundary. Maybe I should try another PC emulator?

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

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Wroclaw, Poland,
09.11.2008, 14:36

@ RayeR
 

DOS on Compaq EVO T20 thin client - possible?

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I have strange problems with downloading entire image. Can you post just the partition table and boot sectors (NT and DOS), or simply send them directly to me? (The partition table, even if ignored by your BIOS at boot, is needed later by DOS when it assigns drive letters. MS-DOS 7 looks at the partition table even earlier, in the boot sector loader.)
RayeR

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CZ,
09.11.2008, 16:36
(edited by RayeR, 09.11.2008, 20:42)

@ mht
 

DOS on Compaq EVO T20 thin client - possible?

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> I have strange problems with downloading entire image. Can you post just
> the partition table and boot sectors (NT and DOS), or simply send them
> directly to me? (The partition table, even if ignored by your BIOS at
> boot, is needed later by DOS when it assigns drive letters. MS-DOS 7 looks
> at the partition table even earlier, in the boot sector loader.)
Yes I can send it to you (its 0.5MB packed) but I don't see your mail anywhere. Mail me at rayer ^ seznam * cz.
BTW I saw you have Compaq EVO N600 notebook too. Did you succed with sound under DOS? It has ESS1869 PCI soudchip which should be some way SB compatible. I was fiddling with many drivers but I made working only the FM sythesis not WAVE soud. Often it hangs. Only MPX play and one version of DOS DOOM engine can play. The same in windows 98. So I'm stucked on emulators :(

Note: I tried VMWare but it cannot setup HDD with more than 16 heads so it very limits usable capacity.

EDIT:

I put to bootsector a simple&dirty code to get BIOS HDD params:

        mov ah,8
        mov dl,80h
        int 13h           

        push dx   ; vypis CH-CL-DH-DL
        push cx
        mov ah,0eh
        mov bl,7

        pop dx ;cx

        mov al,dh ;ch.h
        shr al,4
        add al,'0'
        int 10h

        mov al,dh ;ch.l
        and al,0Fh
        add al,'0'
        int 10h

        mov al,'-'
        int 10h

        mov al,dl ;cl.h
        shr al,4
        add al,'0'
        int 10h

        mov al,dl ;cl.l
        and al,0Fh
        add al,'0'
        int 10h

        mov al,'-'
        int 10h

        pop dx ;dx

        mov al,dh ;dh.h
        shr al,4
        add al,'0'
        int 10h

        mov al,dh ;dh.l
        and al,0Fh
        add al,'0'
        int 10h

        mov al,'-'
        int 10h

        mov al,dl ;dl.h
        shr al,4
        add al,'0'
        int 10h

        mov al,dl ;dl.l
        and al,0Fh
        add al,'0'
        int 10h

        int 20h

The resul was:
CH=02, CL=38, DH=CF, DL=01 > CYL=2, MAXSEC=56, MAXHD=207, DRIVES=1
so my HDD image params are OK. I still cannot figure why I have problems accessing largers sectors of image in Boch. I tried linux version too. And Qemu is limited to 16 heads.

EDIT2:
I also tried SysLinux 3.72 but it quickly end up with "Boot error" on T20 :(

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

11.11.2008, 09:31

@ RayeR
 

DOS on Compaq EVO T20 thin client - possible?

Post reply

> BTW I saw you have Compaq EVO N600 notebook too. Did you succed with sound
> under DOS? It has ESS1869 PCI soudchip which should be some way SB
> compatible. I was fiddling with many drivers but I made working only the
> FM sythesis not WAVE soud. Often it hangs. Only MPX play and one version
> of DOS DOOM engine can play. The same in windows 98. So I'm stucked on
> emulators :(
I can remember from my early Linux day that some ESS chips worked better in WSS (windows sound system) mode than in SB mode.
RayeR

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CZ,
11.11.2008, 16:58

@ RayeR
 

DOS on Compaq EVO T20 thin client - possible?

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I found a way how to overcome problem with accessing disk image in BOCHS. When I temporarly switch partition type from 04 to 0Eh I can access entire image. But it doesn't work on T-20 because BIOS probably doesn't support LBA INT 13h BIOS extension. Here's my bochsrc.txt for image posted above and error log when hanged accessing sector >969

I did some further experiemnts:
1) I used GRUB4DOS 0.4.4 to boot directly freedos kernel.sys
- failed on init disk phase
[image]
2) I used GRUB4DOS 0.4.4 to load 1,44M FD image with freedos
- failed due to missing INT 15h BIOS service
[image]
3) I used GRUB4DOS 0.4.4 to load memdisk (syslinux 3.72) and
then load 1,44M FD image
- failed with some strange error
[image]
I also tried HDD image harddisk=0 c=150 h=4 s=17 (tested
in bochs) and memdisk loaded it but didn't run, ended
with "loading boots ector... booting..."

I used this hellchain: NTBootSector->NTLDR->GRLDR->MEMDISK->kernel|image

Maybe the only way will be compile own FD kernel with HDD geometry hardcoded...

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

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Berlin, Germany,
11.11.2008, 20:31

@ RayeR
 

DOS on Compaq EVO T20 thin client - possible?

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> Maybe the only way will be compile own FD kernel with HDD geometry
> hardcoded...
Did you already ask Eric Auer for some advice?

---
Forum admin
Rugxulo

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Usono,
11.11.2008, 20:48

@ rr
 

DOS on Compaq EVO T20 thin client - possible?

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> > Maybe the only way will be compile own FD kernel with HDD geometry
> > hardcoded...
>
> Did you already ask Eric Auer for some advice?
I'm pretty sure he'd tell you to first get a newer FreeDOS kernel than 2035. For instance, here (and srcs here, taken from SVN).
RayeR

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CZ,
11.11.2008, 21:18

@ Rugxulo
 

DOS on Compaq EVO T20 thin client - possible?

Post reply

> I'm pretty sure he'd tell you to first get a newer FreeDOS kernel than
> 2035. For instance,
I tried 2038 dated this year (maybe it is from your floppy :) I don't remember) but it also don't work. I'll ask Eric but didn't see him on icq longer time.

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

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Berlin, Germany,
11.11.2008, 21:40

@ RayeR
 

DOS on Compaq EVO T20 thin client - possible?

Post reply

> I tried 2038 dated this year (maybe it is from your floppy :) I don't
> remember) but it also don't work. I'll ask Eric but didn't see him on icq
> longer time.
AFAIK he's in Berlin now? So better try mailing him.

---
Forum admin
Rugxulo

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Usono,
12.11.2008, 00:24

@ RayeR
 

DOS on Compaq EVO T20 thin client - possible?

Post reply

> > I'm pretty sure he'd tell you to first get a newer FreeDOS kernel than
> > 2035. For instance,
>
> I tried 2038 dated this year (maybe it is from your floppy :) I don't
> remember) but it also don't work. I'll ask Eric but didn't see him on icq
> longer time.
Then also try 2037 or 2036 (both available on my page among other versions).

But yes, e-mailing Eric is best. He's (still?) moving to Berlin, as rr said.
mht

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Wroclaw, Poland,
12.11.2008, 17:44

@ RayeR
 

DOS on Compaq EVO T20 thin client - possible?

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All this looks very strange!

Maybe you should also test AH and CF returned by INT 13h/08h, and see what is reported by INT 13h/15h. You can also try to read subsequent sectors to see when a problem occurs. Maybe filling the remaining sectors of the image with simple data, as sector numbers, would be helpful in verifying if BIOS is doing in INT 13h exactly what it is asked for...
RayeR

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CZ,
14.11.2008, 22:10

@ mht
 

DOS on Compaq EVO T20 thin client - possible?

Post reply

> All this looks very strange!
>
> Maybe you should also test AH and CF returned by INT 13h/08h, and see what
> is reported by INT 13h/15h. You can also try to read subsequent sectors to
> see when a problem occurs. Maybe filling the remaining sectors of the
> image with simple data, as sector numbers, would be helpful in verifying
> if BIOS is doing in INT 13h exactly what it is asked for...
I think there shouldn't be problem with reading sectors of image because ntrld+grub4dos can load quite large files (like linux kernel and initrd) from the drive without any corruption.
But I'm very confused why loading HD image via memdisk don't work. Image that I'm loading use standard geometry and mbr/dbr placement and memdisk should provide own int 13h services for it but doesn't work. It's very time consuming make this tries when you must encapsulate more images together upload and reflash it...

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

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Wroclaw, Poland,
17.11.2008, 09:45

@ RayeR
 

DOS on Compaq EVO T20 thin client - possible?

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The problem with memdisk may be related to some problem with INT 13/08.

The flash disk geometry is not necessarily fixed, BIOS may try to adjust it somehow (by looking into Partition Table? or Partition Boot Record?)...

By the way, DOS memory managers may have problems with recognizing extended memory due to lack of some related functions.
RayeR

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CZ,
24.11.2008, 23:28

@ mht
 

DOS on Compaq EVO T20 thin client - possible?

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> The problem with memdisk may be related to some problem with INT 13/08.
But I though that memdisk install its own int 13h handler so when accessing the image loaded by memdisk it shouldn't call old BIOS service and use memdisk one instead.

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

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CZ,
29.11.2008, 22:20

@ mht
 

Yes, dynamic CHS!

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> The flash disk geometry is not necessarily fixed, BIOS may try to adjust
> it somehow (by looking into Partition Table? or Partition Boot
> Record?)...
Yes you got point, the CHS is not hardcoded but T20 BIOS will asign it according partition table or bootsector BPB. I just tried to make a new image with different CHS=140/16/32 (now any problems in BOCHS) and flashed it with new fw. I load my HDD BIOS info via GROB4DOS and it displayed:

[image]
heads=16, cyls=139, spt=32
drive type=HDD, sectors=0x16000001 (369098753) - bullshit

And for comparison here's output from BOCHS:

  Booting 'FreeDOS kernel 2038'

INT 13h/08h (DH=heads-1, CX15:6=cyls-1, CX5:0=sec/track-1):
F=0206 CS=0000 SS=0000 ES=0000 DS=0000 DI=7C00 SI=0142 BP=1ED8 SP=1E5A
BX=8107 DX=0F01 CX=8A20 AX=0000

INT 13h/15h (AH=type [3=HDD], CX:DX=sectors):
F=0206 CS=0000 SS=0000 ES=0000 DS=0000 DI=7C00 SI=017E BP=1ED8 SP=1E5A
BX=8107 DX=1600 CX=0001 AX=0300

heads=16, cyls=139, spt=32
drive type=HDD, sectors=0x00011600 (71168 = 139*16*32)

As you can see CHS is the same, so T20 BIOS was adapted to new geometry. But there's an obvios bug in functiom 15h where CX:DX is swapped! I don't know if this can confuse FD kernel. But FD krernel (2038cvs) still fails boot and halt after INITDISK. BTW I tried both version compiled by WC and TC and it behaves different. WC version stops with interrupt divide by zero and TC version starts to endlessly flood the screen by missing command interpretter or so.
BTW as I said before, GRUB and NTLDR can read large files (like linux kernel) without any corruption why FD kernels read it different?

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

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Düsseldorf, Germany,
30.11.2008, 12:49
(edited by cm, 30.11.2008, 13:00)

@ RayeR
 

Yes, dynamic CHS!

Post reply

> BTW as I said before, GRUB and NTLDR can read large files (like linux
> kernel) without any corruption why FD kernels read it different?
Does the BIOS provide LBA disk access as well? Possibly they both use LBA ignoring all the CHS crap.

---
l
RayeR

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CZ,
30.11.2008, 18:13

@ ecm
 

Yes, dynamic CHS!

Post reply

> Does the BIOS provide LBA disk access as well? Possibly they both use LBA
> ignoring all the CHS crap.
Hehe, but T20 BIOS doesn't support LBA services (why when it use only a small flashdisk).
Anyway yesterday night I spent with messing with FD kerner 2038cvs sources,
I enabled debug output to see whats happening, I fixed some bugs
in printing and total sectors calculation and the most important I had
to hardcode nUnits = 3 in initdisk.c because it accidentally rised to 551 -
I have no idea why but then it works!

[image]

I'm in contact with Eric Auer so I hope he give me some explanation
and fix it much better.

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

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Düsseldorf, Germany,
30.11.2008, 20:34

@ RayeR
 

Yes, dynamic CHS!

Post reply

> > Does the BIOS provide LBA disk access as well? Possibly they both use
> LBA
> > ignoring all the CHS crap.
>
> Hehe, but T20 BIOS doesn't support LBA services (why when it use only a
> small flashdisk).

It would be useful especially for flashdisks because you otherwise have to create those CHS values. The T20 BIOS apparently does this by reading the MBR or BPB - that's a really bad idea for the BIOS. LBA calls are just easier to use and, I presume, easier to translate in the BIOS if you're addressing a flashdisk.

---
l
RayeR

Homepage

CZ,
30.11.2008, 22:34

@ ecm
 

Yes, dynamic CHS!

Post reply

> It would be useful especially for flashdisks because you otherwise have to
> create those CHS values. The T20 BIOS apparently does this by reading the
> MBR or BPB - that's a really bad idea for the BIOS. LBA calls are just
> easier to use and, I presume, easier to translate in the BIOS if you're
> addressing a flashdisk.
OK, but it has no sense imagine "what would be if". BIOS is written and I cannot do large mods to it.

But now I have patched FreeDOS kernel well to successfull boot (there was some problem with uninitialized variable, maybe due to my Watcom 11.x compiler, dunno but it's solved) Step 2 completted, but there's next challenge with USB keyboard support, see new thread.

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

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Germany (West),
02.12.2008, 13:34

@ RayeR
 

Yes, dynamic CHS!

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> But now I have patched FreeDOS kernel well to successfull boot (there was
> some problem with uninitialized variable, maybe due to my Watcom 11.x
> compiler, dunno but it's solved)

now it would be kind if you shared your insight about uninitialized variables and your patches with the rest of the world.
RayeR

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CZ,
02.12.2008, 17:14

@ tom
 

Yes, dynamic CHS!

Post reply

> now it would be kind if you shared your insight about uninitialized
> variables and your patches with the rest of the world.
I already sent it to Eric Auer, I'm not FD kernel maintaner.

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

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CZ,
03.12.2008, 04:21

@ RayeR
 

DOS demo show on T20!

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http://rayer.ic.cz/350d/t20boot.avi

Yeah, it's booting and it's playing! Onboard sound seems to be SB16 compatible (some kind of SW emulation embedded in BIOS with HW support via legacy res. trapping to SMI). But the USB keyboard is the killer :(

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

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Usono,
06.12.2008, 12:13

@ RayeR
 

DOS demo show on T20!

Post reply

> http://rayer.ic.cz/350d/t20boot.avi
>
> Yeah, it's booting and it's playing! Onboard sound seems to be SB16
> compatible (some kind of SW emulation embedded in BIOS with HW support via
> legacy res. trapping to SMI). But the USB keyboard is the killer :(
You'll probably have more luck (and supporters) getting GNU/Linux or one of the BSDs to run instead. (Ah, I see in the other thread that you're running Debian.)

P.S. Compaq is now owned by HP, so maybe they can help?? EDIT: Dunno who would be best to contact, though. But they are huge, so they're bound to have somebody in the know.
RayeR

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CZ,
07.12.2008, 13:34

@ Rugxulo
 

DOS demo show on T20!

Post reply

> P.S. Compaq is now owned by HP, so maybe they can help?? EDIT: Dunno who
> would be best to contact, though. But they are huge, so they're bound to
> have somebody in the know.
Hehe good joke. I have some experiences with technical support around hp ipaq 214 (the latest model) and I was very disappointed by they work (but this is another story). I doubt they would support such old hardware and even could answer such low level things about bios. BTW BIOS was written by WYSE (and all HW seems to be made by them) so HP wouldn't know they just stick the logo :)

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

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Berlin, Germany,
07.12.2008, 16:56

@ RayeR
 

DOS demo show on T20!

Post reply

> Hehe good joke. I have some experiences with technical support around hp
> ipaq 214 (the latest model) and I was very disappointed by they work (but
> this is another story).
My experiences with HP support are good. I had problems finding the correct modem driver for my Evo N620c. My chat partner at HP was very obliging and helpful.

---
Forum admin
mht

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Wroclaw, Poland,
08.12.2008, 20:31

@ RayeR
 

DOS demo show on T20!

Post reply

> Hehe good joke. I have some experiences with technical support around hp
> ipaq 214 (the latest model) and I was very disappointed by they work (but
> this is another story).

(off-topic) What is your experience with iPAQ 214 itself? I was recently asked for advice whether it is worth buying or not, so your opinion would be very helpful.
RayeR

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CZ,
08.12.2008, 21:06
(edited by RayeR, 08.12.2008, 21:20)

@ mht
 

DOS demo show on T20!

Post reply

> (off-topic) What is your experience with iPAQ 214 itself? I was recently
> asked for advice whether it is worth buying or not, so your opinion would
> be very helpful.
Good and bad. I used previously ipaq h2210 so I compared 214 to it.
some highlighted pros/cons:
+much better display (640x480 gives pretty fine image, good for maps)
+strong backlight with optional ambient sensor auto adjust
+keep both CF and SD slot
+wifi
+USB host capability
+battery lifetime
+enough power for playing divx 640x480
+plenty of ram, and some internal flash

-missing IrDA (h2210 can be used as universal remore controller for home A/V)
-missing serial port on system connector but you can use FTDI232 USB adapter
-is larger (it could be made smaller keeping LCD size)
-plastic body (compared to older hx4700) but when you take a care it's not problem
-too thin stylus
-worse audio output (clicking when audio turned on/off, weak background noise)
-older series has poorly assembled LCD and protective foild and it was very hard to tap on screen (I got replaces entire PCB and LCD so now it's much better, I don't use aditional scr. protector)
-CF slot power management is some way HW or SW buggy. I got battery drain when CF insterted even during power off state. I contacted hp support and they tried to make me idiot to belive this is right. But after some effort on second visit of service center I got replaced PCB and LCD. But problem still partially persist. I can avoid it when I press reset button and then turn off PDA it will not drain the battery and it can stay many days with minimal droop. But once I access CF and turn it off it will get drained. I had bought 16GB CF which I also share with my digicam (EOS 350D) but if you don't need CF I strongly reccomend use SDHC which doesn't suffer this problem.
-OS (WM6.0) speed doesn't match much higher CPU speed (when I hold 1st time an iphone I wonder how perfectly smooth moving GUI can be made on slower system - shame on micro$of) -OS doesn't utilize the potential of large screen resolution, you just get big smooths icons instead of more objects on screen (there's a way to switch to true VGA mode but it may be too small)
-hp will probably not upgrade ROM to further WM

Despite a lot of minus (I can say it freely coz I'm not paid for a review :) at finally after about 1/2 years of using 214 I think it's quite good PDA and I will never return to h2210. I mostly utilized the better LCD (reading books, Ozi maps, GPS testing...) and WiFi and battery life. I also did soldered homemade USB host cable so I can connect FTDI serial adapter when needed, big PC keyboard and more...

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

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Wroclaw, Poland,
08.12.2008, 21:28

@ RayeR
 

DOS demo show on T20!

Post reply

Many thanks! Just one more question: Is it possible to configure its screen in "landscape" mode?
RayeR

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CZ,
09.12.2008, 11:55

@ mht
 

DOS demo show on T20!

Post reply

> Many thanks! Just one more question: Is it possible to configure its screen
> in "landscape" mode?
I don't know if WM itself can, I never needed it. But e.g. Coreplayer of course can.

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