Accessing DOS disk with ISC

[Dave McLane]

A while back somebody said they were having troubles accesing DOS
disks under (ISC I think) UNIX. I'd been using VPIX which works OK
for me and I'd been able to mount a DOS disk and access it as UNIX,
but when I went to use dossette I had problems: some of the time it
would work and some of the time it wouldn't.

The main problem was that if I just said:

  $ dossette
  A> dir

The disk read light would flicker on, and (in the beginning
unbeknownst to me) an error message would appear on the console
saying to insert the disk.

I found that if I mounted the DOS disk as root with:

  # mount -f DOS /dev/dsk/f0q15dt /mnt

I/anybody could access it as a UNIX file system but I/anybody
couldn't access it with dossette commands as they gave an error
message.

The solution (workaround?) was to use the following sequence:

  # mount -f DOS /dev/dsk/f0q15dt /mnt
  # umount /dev/dsk/f0q15dt

And then use:

  $ dossette                  ; doesn't access disk
  A> a:                       ; accesses disk
  A>                          ; OK now

As long as the drive door remained closed, anybody can access the
disk (one at a time) with dossette; but the minute the door's been
opened it is necessary to mount/umount the/a disk.

I've made life easy by creating a "floppy" script which I run as root:

  === floppy ====
  mount -f DOS /dev/dsk/f0q15dt /mnt
  umount /dev/dsk/f0q15dt

Seems weird and I would hope there would be better solution, but it
works....

--Dave