[net.micro.pc] Disk Error Handler Bug

jkimmelm%bbn-vax@sri-unix.UUCP (04/24/84)

From:  Jeff Kimmelman <jkimmelm@bbn-vax>

I just ran into what I think is a definite bug (feature) of MS-DOS.  I was
performing an operation which required a disk write to a floppy drive which
(accidentally) had a write protected diskette inserted.

I got the usual message and the question Abort, Retry, or Ignore?  I
immediately got out the (backed up) diskette I had intended the write to go
to and inserted it.  Was I ever suprised--after the write my directory had
an exact copy of the directory from the write protected diskette!!!!  Now
come on guys, I know that the directory is just a file which must be read,
updated, and rewritten, but is it so difficult to reread after a diskette
error?  Is there a philosophy behind all this or did they just make a
boo-boo?  Perhaps someone has a patch to avoid crashing the directory of
the disk in such a simple, straightforward manner.  If so I would be very
appreciative if you would help me out.

By the way, I was using Kermit on an Eagle PC-Plus when the bug bit if that
is of any use.

Cheers
--Jeff Kimmelman (=JKIMMELMAN@BBN-UNIX)

[Ed:  This has happened to me, and I for one make it a practice to never
let DOS or any program retry a write under these circumstances.  I don't
know if this is a bug or a "feature"]

jph@whuxle.UUCP (05/14/84)

#R:sri-arpa:-19800:whuxle:22700031:000:458
whuxle!jph    May 10 08:40:00 1984

Your problem was that you `changed' floppies while you had a
file OPENed. There are words in the manual that sya if you
do this, your directory can get messed up. Now true, after
an error, maybe things shoudl be re-read, but what if you
have a program executing that had several files open on the
floppy at once. What happens in this case. So a word to the
`wise' is not to change disks in the middle of an operation.
Instead, restart it from the beginning.