From: ao950 AT FreeNet DOT Carleton DOT CA (Paul Derbyshire)
Newsgroups: comp.os.msdos.djgpp
Subject: Weird crash with bad array
Date: 18 Feb 1997 06:45:18 GMT
Organization: The National Capital FreeNet
Lines: 23
Message-ID: <5ebj5u$meq@freenet-news.carleton.ca>
Reply-To: ao950 AT FreeNet DOT Carleton DOT CA (Paul Derbyshire)
NNTP-Posting-Host: freenet2.carleton.ca
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp



I mallocked a chunk of memory to hold a 300x15 array of short ints. The
way I indexed it, the address was short *baseptr + y*300+x. Thus, a bad x
coordinate would not generally go out of the malloc block but a bad y
coordinate would.
I accidentally wound up trying to access it at y=21... the resulting crash
was spectacular and somewhat alarming. The computer made a popping noise,
then rebooted itself, then froze in mid-reboot with the message "Drive
failure"!

I switched it physically off for a few seconds and on again. It came up
with "drive failure" again but otherwise booted normally and all my disk
drives worked fine. Since then it has never repeated the messgae, at boot
or otherwise.

What could cause such an alarming message?

--
    .*.  Where feelings are concerned, answers are rarely simple [GeneDeWeese]
 -()  <  When I go to the theater, I always go straight to the "bag and mix"
    `*'  bulk candy section...because variety is the spice of life... [me]
Paul Derbyshire ao950 AT freenet DOT carleton DOT ca, http://chat.carleton.ca/~pderbysh