DOS ain't dead - SEEKEXT and enabling unsigned 32-bit DOS int 0x21 fileseeks?

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

posted by Oso2k, 22.10.2021, 00:39

[SNIP]
>
> I was dealing specifically with SFNs, but did of course have the FAT32
> version of DOS (ie, the "unofficial v. 7.1" released with Win 95 OSr2 and
> Win 98). Didn't have any LFN support loaded, however. And, I suspect, as
> you said, the 16-bit DOS programs simply don't know how to deal with
> "negative" file sizes, bombing out on any seek activity, once they see a
> "negative" filesize (> 2 GiB) as an overflow error.
>
> If there is a special flag, I'm unsure how to enable it or if it indeed
> needs to be enabled at compilation and therefore programs need to be
> recompiled in order to enable the flag at runtime.
>
> I thought R. Loew had somehow overcome this problem, but it seems not
> generally via an IO.SYS patch. His FAT32+ utilities and patches seem to
> correctly support unsigned access (correctly only identifying a -1 value
> (0xFFFFFFFF), and thus utilizing the full FAT32 capability, and also
> enabling files of > 4 GiB by means of splitting the files into 4 GiB - 1
> sized chunks. However, I believe these "unsigned" fileseeks are only
> supported via his own utility, and NOT in the general sense of all int 21
> calls.

Are you talking about R. Loew's FILE64 package?

https://rloewelectronics.com/distribute/FILE64/FILE64W/README.TXT

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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