DOS ain't dead - DOS API extension for files

DOS API extension for files > 4 GB (Developers)

posted by Japheth , Germany (South), 22.12.2007, 10:28
(edited by Japheth on 22.12.2007, 10:50)

> If, say, a DOS EXE > 4GB is seen as multiple files, how would it be
> executed in Windows?

an error is reported, sort of "invalid .EXE", of course. Not a problem at all.

> Might it be best to accept a max. size of (4G-1) bytes as the price of
> being able to use files in multiple OSes?

No. Even without FAT32+ DOS is missing an API to position at file offsets > 4 GB. With NTFS4DOS, the Paragon drivers or similar things such large files are accessible for DOS apps. So the "API extension" part of FAT32+ is important, even if FAT32+ itself might be crappy.

btw: IMO it might be a good idea to redesign even the API part of FAT32+, since the API extension has been placed into DOS' LFN function group (int 21h, ax=7142h), where it doesn't belong at all. A better place possibly would have been the FAT32 extensions (int 21h, ax=73xxh). And in the FAT32+ concept, the API needs a pointer to a 64bit value, which makes such a call unnecessary complicated for DOS extended programs. A simple int 21h call with the offset hold in registers (SI:DI:DX:CX? or maybe just DI:DX:CX?) would have been preferable.

---
MS-DOS forever!

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Complete thread:

GetFileSizeEx / Read&Write performance / Wiping - DOS386, 21.12.2007, 03:40 (Developers)
- GetFileSizeEx / Read&Write performance / Wiping - Steve, 21.12.2007, 05:38
- The Death Of FAT32+ - Japheth, 21.12.2007, 07:24
  - --- DEATH --- - DOS386, 21.12.2007, 22:13
    - --- DEATH --- - sol, 21.12.2007, 22:30
      - --- DEATH --- - DOS386, 21.12.2007, 22:46
        --- DEATH --- - Steve, 21.12.2007, 23:22
    - Rest in Peace, Fat32+! No Resurrection possible! - Japheth, 21.12.2007, 23:12
      - -- DEATH -- (anyone has a solution for >4GiB files in DOS ?) - DOS386, 21.12.2007, 23:46
        First get all facts! - Japheth, 22.12.2007, 00:15
        --- DEATH --- - DOS386, 22.12.2007, 00:24
        --- DEATH --- - sol, 22.12.2007, 05:17
        --- DEATH --- - Japheth, 22.12.2007, 09:45
        --- DEATH --- - Steve, 22.12.2007, 10:08
        DOS API extension for files > 4 GB - Japheth, 22.12.2007, 10:28
        --- DEATH --- - sol, 23.12.2007, 23:29
        --- DEATH --- - Matjaz, 24.12.2007, 10:03
        DOS File System efforts - Japheth, 24.12.2007, 17:06
        DOS File System efforts - Rugxulo, 24.12.2007, 19:53
        DOS File System efforts - sol, 25.12.2007, 02:17
        DOS File System efforts - Japheth, 25.12.2007, 09:10
        DOS File System efforts - Rugxulo, 26.12.2007, 21:34
        HPFS for DOS - Rugxulo, 09.09.2008, 22:48
        --- DEATH --- - Japheth, 22.12.2007, 08:57
  - 1 a later, DOS fs enh committee, please report what you got - DOS386, 29.12.2008, 02:41
    - Just noise? - Japheth, 29.12.2008, 08:07
      - NOISE-FS outperforms them all !!! - DOS386, 30.12.2008, 23:06
        NOISE-FS outperforms them all !!! - Japheth, 31.12.2008, 11:46
        NOISE-FS outperforms them all !!! - sol, 02.01.2009, 01:59
        NOISE-FS outperforms them all !!! - Rugxulo, 02.01.2009, 04:25
    - better DOS file system? - Rugxulo, 29.12.2008, 23:16
      - better DOS file system? - ecm, 30.12.2008, 21:48
    - 1 a later, DOS fs enh committee, please report what you got - Steve, 02.01.2009, 07:01
- GetFileSizeEx / Read&Write performance / Wiping - Laaca, 11.01.2009, 14:14
  - exFAT - ecm, 11.01.2009, 17:30
  - GetFileSizeEx / Read&Write performance / Wiping - Rugxulo, 12.01.2009, 19:25
    - GetFileSizeEx / Read&Write performance / Wiping - sol, 15.01.2009, 05:26
      - GetFileSizeEx / Read&Write performance / Wiping - Rugxulo, 15.01.2009, 06:13
        GetFileSizeEx / Read&Write performance / Wiping - sol, 15.01.2009, 06:24
        GetFileSizeEx / Read&Write performance / Wiping - Rugxulo, 16.01.2009, 01:49
        GetFileSizeEx / Read&Write performance / Wiping - sol, 16.01.2009, 07:03
        GetFileSizeEx / Read&Write performance / Wiping - Rugxulo, 18.01.2009, 00:14
        4desasters 4u, DOSsers - DOS386, 24.01.2009, 09:42
        FAT+/FAT/patents - ecm, 24.01.2009, 13:59
        4desasters 4u, DOSsers - Japheth, 24.01.2009, 21:01
        GetFileSizeEx / Read&Write performance / Wiping - Laaca, 14.02.2009, 13:59
        exFAT supported in XP (SP2, SP3) - Rugxulo, 19.02.2009, 02:41
        exFAT supported in XP (SP2, SP3) - Japheth, 20.02.2009, 09:07
        exFAT supported in XP (SP2, SP3) - Laaca, 20.02.2009, 20:16
        exFAT supported in XP (SP2, SP3) - Zyzzle, 21.02.2009, 01:56
        exFAT supported in XP (SP2, SP3) - sol, 21.02.2009, 05:32
        exFAT supported in XP (SP2, SP3) - Rugxulo, 21.02.2009, 05:40
        exFAT supported in XP (SP2, SP3) - Laaca, 21.02.2009, 15:57
        exFAT in FreeDOS unlikely (but FD fixed 4 GB files) - Rugxulo, 15.03.2009, 15:55
        exFAT in FreeDOS unlikely (but FD fixed 4 GB files) - ecm, 15.03.2009, 20:36
        exFAT in FreeDOS unlikely (but FD fixed 4 GB files) - Rugxulo, 17.03.2009, 00:28
        exFAT specification - tom, 17.03.2009, 19:31
        exFAT specification - Laaca, 21.03.2010, 15:42
        former-FAT - DOS386, 22.03.2010, 08:15