Date   : Sat, 21 Jan 1984 01:54:00 EST
From   : Jerry E. Pournelle <POURNE@mit-mc>
Subject: How to mangle a disk.

thanks; yet (and I have to rely on what others tell me for this)
I am told that using 13 is safe; I do know that we have done
what looks like what you describe with no bad consequences; the
BIOS checks for it.  One thing we do a lot is change disks while
fioles are in the text editor; this makes backup copies.  At one
time the system used to go to the A disk once, then stay with
the b; the double klunk was a bit slow, so Tony tried to
eliminate it by using 37; no disasters with us, but we did get a
hang conditin once.  He looked into it; then we installed the
program on MPM 8/16 systems, and there was a furious rewrite,
and now it klunks to the A disk, then to the logged on disk,
then the A gain, then writesd to the logged on. I ain't sure
what's happening, but it is completely bulletproof; not even
Alex can crash it and he can crash almost anything.
       It was then I was told that 37 could cause disasters,
and after I became sensitized to listen for fn 37 horror stories
I heard more; and now our wizards refuse to use 37; that is
about my last comment on the subject, since I am reporting what
others tell me, not what I really know.  I have tried to study
the documentation for those functions,a and they don't trell me
a lot.