(off-the-laptop-topic, sorry)
Declan,
> As a newbie to Linux, I need to know does Linux have a good disk editor
> for floppies? I need to read a non standard floppy format, and copy
> disks with it.
You could try reading from the "raw" floppy device with the 'dd'
command. This should give you hints about how "PC compatible" the
format of the disks are.
I *believe* (could be mistaken, though) that the /dev/fd devices only
handles "normal" floppy formats, and not ones where, let's say the
tracks are of non-standard length (with non-standard gap lengths).
Anyway, my idea is that using dd, similar to this example;
# dd if=/dev/fd0 of=disk_image.raw bs=72k count=10
would yield error messages (bad sector etc.) if the disk contains a
non-standard ("PC-unreadable") format, and a valid disk image in
the file disk_image.raw if it is just the filesystem that is
unstandard.
In case of the latter, you can write it back to a fresh floppy with
# dd if=disk_image.raw of=/dev/fd0 bs=72k count=10 ; sync
You might want to try different values for the blocksize (bs) and
count parameters, but the result should be the same.
Don't forget to write protect the original disks! :-)
If you manage to create the disk image file, you can use any hex
editor to snoop around and hack it before writing it back to another
disk.
I know way too little about how 3.25" floppy drives work and how
programmable/controllable they are. Is there a way to for instance
change the rotational speed? Do you control the step motor yourself,
or do you just give the drive a track number?
> Although the drive is pc compatible, the
> format certainly isn't. The disk is written by a drive in an external
> box, which talks to his pc through a com port & dongle.
Does the external box that creates the floppies contain a
"PC-compatible" drive too?
Other things to try: amiga and macintosh.
I have a vague memory of the amiga being able to read each MFM bit
from a floppy, and I think the mac spins the floppy at different
speeds depending on where the read head is.
Good luck!
Mattias
