Xref: utzoo comp.sys.ibm.pc:15953 comp.arch:5005 comp.graphics:2576
Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!husc6!linus!mbunix!jcmorris
From: jcmorris@mitre-bedford.ARPA (Joseph C. Morris)
Newsgroups: comp.sys.ibm.pc,comp.arch,comp.graphics
Subject: Re: How did this program burn out two monitors?
Message-ID: <33072@linus.UUCP>
Date: 27 May 88 13:28:35 GMT
References: <10244@agate.BERKELEY.EDU>
Sender: news@linus.UUCP
Reply-To: jcmorris@mbunix (Morris)
Organization: The MITRE Corporation, McLean, VA.
Lines: 17

In a recent article willis@violet.berkeley.edu (Willis Johnson) writes:
>                              When I ran the .exe file, my monitor
>made a high-pitched whine, then the power light went off, and a 
>crackling noise came out of the back until I pulled the power cord.

I don't have any experience with the Hercules board, but it's likely
that you clobbered one of the registers which controls the oscillators
which drive the deflection circuits in the monitor.  The anode voltage
(the really high voltage -- above 20KV in color displays) is derived
from the horizontal deflection circuits, so if you scribbled on the
registers which control horizontal drive you could make the circuit
run in a manner which could cause troubles.

A few packages I've seen include warnings in their documentation that you
need to select the proper video driver or you could damage the display.
You would think that the designers would include protection against 
likely damage, but I guess that's too much to ask...