Very Computer

I'm trying to make some extra high capacity ext2 floppies, but some of the
formats don't seem to be working.  This should explain it...

[root:/tmp]# fdformat /dev/fd0H1722
Double-sided, 82 tracks, 21 sec/track. Total capacity 1722 kB.
Formatting ... done
Verifying ... done
[root:/tmp]# fdformat /dev/fd0H1760
Double-sided, 80 tracks, 22 sec/track. Total capacity 1760 kB.
Formatting ... done
Verifying ... read: I/O error
[root:/tmp]# fdformat /dev/fd0H1743
Double-sided, 83 tracks, 21 sec/track. Total capacity 1743 kB.
Formatting ... done
Verifying ... done

it seems that more than 21 sec/track doesn't work.  This disk was a perfectly
good 2M disk under DOS.  Is this a bug in the floppy driver?  I'm using Linux
version 1.1.50 and got the new mtools and floppy utilities package. BTW, this
[root:/tmp]# fdformat /dev/fd0H360
Double-sided, 80 tracks, 9 sec/track. Total capacity 360 kB.

is wrong, it should be SAY single sided.  getfdprm says 720 9 1 80, so it's a
bug in fdformat.

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: I'm trying to make some extra high capacity ext2 floppies, but some of the
: formats don't seem to be working.  This should explain it...
[...]
: [root:/tmp]# fdformat /dev/fd0H1760
: Double-sided, 80 tracks, 22 sec/track. Total capacity 1760 kB.
: Formatting ... done
: Verifying ... read: I/O error
 It was a rather silly error in the drive geometry table... The following
patch should take car of that:
--- linux-1.1.52/drivers/block/floppy.c Thu Oct  6 20:56:59 1994

        { 2080,13,2,80,0,0x1C,0x01,0xCF,0x6C,"D1040" }, /* 21 1.04MB 3.5"   */
        { 2240,14,2,80,0,0x1C,0x19,0xCF,0x6C,"D1120" }, /* 22 1.12MB 3.5"   */
        { 3200,20,2,80,0,0x1C,0x20,0xCF,0x6C,"h1600" }, /* 23 1.6MB 5.25"   */
-       { 3520,22,2,80,0,0x1C,0x08,0xCF,0x6C,"H1760" }, /* 24 1.76MB 3.5"   */
+       { 3520,22,2,80,0,0x1C,0x08,0xCF,0x2e,"H1760" }, /* 24 1.76MB 3.5"   */
        { 3840,24,2,80,0,0x1C,0x20,0xCF,0x6C,"H1920" }, /* 25 1.92MB 3.5"   */
        { 6400,40,2,80,0,0x25,0x5B,0xCF,0x6C,"E3200" }, /* 26 3.20MB 3.5"   */
        { 7040,44,2,80,0,0x25,0x5B,0xCF,0x6C,"E3520" }, /* 27 3.52MB 3.5"   */

(This patch should also work with 1.1.53, the floppy driver didn't change
between the two releases)
 This fixes the problem for 22 sectors, the highest format that uses a
constant sector size, and a positive gap. The formats with bigger capacity
use mixed sector sizes on one track or negative gaps. They can only be made
by the superformat program included in the fdpatches and fdutils packages.

[...]
 Hope this helps,

 Alain