DOS ain't dead

SEEKEXT and enabling unsigned 32-bit DOS int 0x21 fileseeks? (Users)

posted by Rugxulo , Usono, 20.10.2021, 11:10

I'm not sure from first-hand experience, only crumbs of hints from third-party info.

I don't think NTVDM implements 4 GB files for DOS. I think it was only FAT32 (as you mentioned, Win95 OSR2 or whatever) exclusively via int 21h, 716Ch. You might want to ask on news://comp.os.msdos.djgpp since I think there was some (??) support in /beta/ 2.04 and newer (e.g. /current/ 2.05). Actually, I remember that their port (2.04 or newer) of *nix DF.EXE would only use FAT32 routines (int 21h, 7303h ?) if the DOS version reported was 7.

So even that I only barely understand, sorry. (There's also "signed int bugs" as I think Eric called it in the FreeDOS kernel that keep all files 2 GB and less. Similarly, DJGPP makes some hardcoded assumptions about 2 GB address space, last I heard.

7-Zip works? Which version and compile? You mean M.K.'s build of 7z.exe 16.02 or whatever?

Complete thread:

• SEEKEXT and enabling unsigned 32-bit DOS int 0x21 fileseeks? - Zyzzle, 20.10.2021, 05:00 (Users)
  • SEEKEXT and enabling unsigned 32-bit DOS int 0x21 fileseeks? - Rugxulo, 20.10.2021, 11:10
    • SEEKEXT and enabling unsigned 32-bit DOS int 0x21 fileseeks? - Zyzzle, 20.10.2021, 14:37
      • SEEKEXT and enabling unsigned 32-bit DOS int 0x21 fileseeks? - KormaX, 25.11.2021, 17:42
  • SEEKEXT and enabling unsigned 32-bit DOS int 0x21 fileseeks? - ecm, 20.10.2021, 12:50
    • SEEKEXT and enabling unsigned 32-bit DOS int 0x21 fileseeks? - Zyzzle, 20.10.2021, 14:51
      • SEEKEXT and enabling unsigned 32-bit DOS int 0x21 fileseeks? - Oso2k, 22.10.2021, 00:39
        • SEEKEXT and enabling unsigned 32-bit DOS int 0x21 fileseeks? - Zyzzle, 22.10.2021, 02:45
    • SEEKEXT and enabling unsigned 32-bit DOS int 0x21 fileseeks? - KormaX, 26.11.2021, 10:31