Re: Dos 3.3 question

[aa382@Freenet.carleton.ca (Marc Sira)]

In a previous article, uerics@mcl.ucsb.edu (Eric D. Shepherd) says:

>Nothing "viral" about it.  When DOS 3.3 puts up a catalog listing, it
>reads the string "DISK VOLUME" from within the DOS image in memory.  If
>that copy of DOS has been modified to have a different string stored
>there, that string will be displayed instead, no matter what disk is in
>the drive.

You're correct of course, it was easy to modify that string (though changing
the volume number was impossible without reinitialising the disk as I recall).
There really were some "virus" versions of 3.3 floating around, though...I
recall one that could be distinguished by a little sweeping sound made by the
disk head at the end of every CATALOG (it was writing the "virus" onto the
disk that had been cataloged). I believe it was by Mark Fleming (or at least
we referred to it as "FlemingDOS" ;).

Some people commented that the disk may have had an optimised version of
3.3 on it with a different interleave...I don't _think_ this would have
prevented the DOS image (first three tracks basically) from being updated.
It might give a slow-booting disk if you changed the interleave, though.
Skew is a logical concept after all; I think the drive would be able to
find the proper sector in any case.

My suspicion is that the original poster either had no clean version of
DOS to run MASTER CREATE with (or manually copy) or he CATALOGed the disk(s)
being repaired while a flaky DOS was still in memory.

-- 
Marc Sira                  |
aa382@freenet.carleton.ca  |  "Your god drinks...p-p-peach nectar."
toh@micor.ocunix.on.ca     '