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  • USB stick boot like a floppy

    From Kerr-Mudd,John@21:1/5 to Wildman on Sat May 9 19:07:15 2020
    XPost: alt.os.development

    On Sat, 09 May 2020 15:19:40 GMT, Wildman <best_lay@yahoo.com> wrote:

    On Sat, 09 May 2020 10:16:39 -0500, Wildman wrote:

    I used WinImage to extrace the boot sectors from
    the actual discs or images.

    Should have been extract. LOL

    Gosh; it was Nortons Utilities in my day. Till I wrote my own.

    Oh dear, an embarrassing 213 bytes with some of my home-grown routines.
    (still, it's olde DOS only, direct disk access by int 13 is disallowed
    under NT upwards)


    --
    Bah, and indeed, Humbug.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From T. Ment@21:1/5 to T. Ment on Mon May 11 06:08:56 2020
    XPost: alt.os.development

    On Fri, 08 May 2020 03:41:53 +0000, T. Ment wrote:

    Sectors per track is still 18, but heads is now 64.
    Sectors per cluster is 8 instead of 1. Total sectors changed
    from 2880 to 32520.

    27 sectors per track seems to work better. Heads is still 64.

    Instead of calculating total sectors by hand, now I set it to 0FFFFh (at
    offset 13h). Then reboot into DOS and:

    format b: /s

    Don't use /u. The invalid 0FFFFh total sector count makes DOS resize the volume. You get a prompt saying it can't be unformatted. That's what you
    want to see.

    Different USB sticks get different sizes. Not sure why, maybe firmware
    in the stick.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From T. Ment@21:1/5 to T. Ment on Mon May 11 15:37:31 2020
    XPost: alt.os.development

    On Fri, 08 May 2020 12:34:05 +0000, T. Ment wrote:

    I never got it to boot as an A: drive with FAT16. FAT12 is the only way
    it worked.

    I tried RMPrepUSB. Their website is nearly useless because of ads, and
    they want a donation for an ad-free URL. But I found another web site to download their tool.

    They use FreeDOS to create a FAT16 bootable A: drive. But when I reboot
    to DOS 6.22 on my C: drive, I still can't see the USB drive that has
    FreeDOS. So it's DOS 6.22 that can't handle a FAT16 A: (or B:) drive.

    And I need DOS 6.22. So FAT12 it is.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From T. Ment@21:1/5 to T. Ment on Mon May 11 15:55:10 2020
    XPost: alt.os.development

    On Mon, 11 May 2020 06:08:56 +0000, T. Ment wrote:

    27 sectors per track seems to work better. Heads is still 64.

    ZIP disk geometry is 32 sectors per track. I tried that, but the DOS
    6.22 format command fails.

    ZIP disk geometry is 64 heads. Other values format OK, but an old Award
    BIOS sees garbage in the files when booting.

    So for DOS 6.22 and FAT12, 27 sectors and 64 heads are magic numbers.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)