#115 format error in FAT32 kernel


Boot FAT32 kernel (ex. ke2041_86f32) from A: and "format b: /u", then an error occurs.

A:>format b: /u
Insert new diskette for drive B:
Press ENTER when the right disk is in drive...
Using drive default: 1440k (Cyl=80 Head=2 Sec=18)
Please enter volume label (max. 11 chars):
No label, disk will have no creation timestamp.
Full Formatting (wiping all data)
100 percent completed.
Preparing FAT area...
Drive_IO(WRITE 1, count 1 ) [FAT12/16] [drive B*]

Critical error during DOS disk access
DOS driver error (hex): 01
Description: unknown unit for driver
Program terminated.
[Error 129]

Format uses INT26, and this error occurs in kernel.
When "dir b:" before format, then this error does not occur.


  • 7shi

    I reply to the answer on the mailing list.

    Does this only happen with the FAT32 kernel?


    Does this only happen with a FreeDOS kernel?

    Does it mean other DOS, for example, MS-DOS?
    I've tested only with FreeDOS.

    Are your A: and B: actually 2 distinct physical drives?

    Yes, but not with a real machine. I've tested in QEMU.
    I've created a boot floppy "fd1.img" with ke2041_86f32.

    $ dd if=/dev/zero of=fd2.img bs=512 count=2880
    $ qemu -fda fd1.img -fdb fd2.img
    Starting SeaBIOS ...
    FreeCom version 0.82 pl 3 [Dec 10 2003 06:54:37]
    A:\>format b: /u

    Does this only happen with /U or also with other modes?

    Without /U, only in first (unformatted) the error occurs.
    With /U, always the error occurs.

    Can you try with other FORMAT tools?

    No, I don't know other FORMAT tools for FreeDOS.

    If you do DIR B: before format, what will happen?
    Is the disk already formatted before you format it?

    A:\>dir b:
     Volume in drive B has no label
     Volume Serial Number is EF27-3654
    File not found.
    A:\>dir b:
     Volume in drive B has no label
     Volume Serial Number is 3970-18E7
    File not found.

    Can you add the /D option to get more verbose messages?

    I've attached the log.

  • haruteru_f

    Hi All,
    I tried other DOS.

    1.DR-DOS 7.01.07 WIP (24.11.2004)
    => no problem
    2.DR-DOS 8.0
    => no problem
    3.Windows ME boot disk
    => no problem

  • haruteru_f

    I try some case.
    Thanks :-)
    case1. DR-DOS 7.01.07 WIP (24.11.2004)
    -> no problem
    case2. DR-DOS 8.0
    -> no problem
    case3. Windows ME boot disk
    -> no problem

    All with the same FreeDOS FORMAT tool?
    Then it might indeed be kernel-related.

    Yes, all the same FreeDOS format.exe (byte size = 31216)
    * "format.exe" version
    FreeDOS Format Version 0.91v
    Written by Brian E. Reifsnyder, Eric Auer and others.
    Copyright 1999 - 2006 under the terms of the GNU GPL, Version 2.