Minor fix to Mtools patch for 3.5" disks

[John B. Milton]

In article <56 at gnosys.UUCP> gst at gnosys.UUCP (Gary S. Trujillo) writes:
>In article <611 at bacchus.UUCP> darren at bacchus.UUCP (Darren Friedlein) writes:
>>...
>>One thing I'd like to find is a program like MsdosF.sh that will format
>>3.5" disks.  Anyone know how to do this?
>
>For that matter, does anyone know how to format 5.25" floppies at 360K?
>Far as I know, /usr/bin/MsdosF.sh will only format 320K (8-sector) disks.

Well, too bad. The UNIX driver will only format (or use) an even number of
sectors. One way is to format 10 sector and only use 9. You're right, some
times it won't work. In theory, one could be written since the ioctl level
of the floppy driver allow direct commands to the FDC chip. I will take a peak
at it tonight and post a followup.

What I do is just format a bunch of "fresh" (never EVER been formatted) disks
on an AT HD drive in low density. These can be read on an system, and written
just fine on the UNIXpc. If you need to write on the PC side, that's different.

Digression:
 Any time you write to a disk with a 48 tpi drive, you create a wide data track
 on the disk. As long as you never try to write thin (96 tpi) data into an area
 that already has ANY kind of wide (48 tpi) data, you're ok.

 Now everyone is going to post back to the net "well it works fine for me...".
 Well, DON'T! unless you have something significant to add or I goofed :)
 If it worked for you, you've just been lucky. 

If you are doing only 48tpi to 48tpi, never mind!

One thing that is missing (I am assuming now that EVERYONE has Emmet Gray's
mtools) is a command "minit" that will write an empty boot block, FAT (switch
for size code), DIR, and optional volume label. Once we have this tool, we can
convert any UNIXpc disk to an MS-DOS disk quickly. We can also fix one that
got trashed.

I'll get back.

John
-- 
John Bly Milton IV, jbm at uncle.UUCP, n8emr!uncle!jbm at osu-cis.cis.ohio-state.edu
home: (614) 294-4823, work: (614) 459-7641; CP/M to MP/M, MS-DOS to OS/2