Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!apple!oliveb!mipos3!omepd!iwarpj!pcm
From: pcm@iwarpj.intel.com (Phil C. Miller)
Newsgroups: comp.os.minix
Subject: Re: Device drivers damaging HW
Message-ID: <4697@omepd.UUCP>
Date: 26 Jul 89 12:16:16 GMT
References: <13679@ea.ecn.purdue.edu>
Sender: news@omepd.UUCP
Reply-To: pcm@iwarpj.UUCP (Phil C. Miller)
Organization: Intel Corp., Hillsboro
Lines: 25

In article <13679@ea.ecn.purdue.edu> jel@ecn.purdue.edu (Jim Lumpp) writes:
>
>I am not very familiar with IBM peripheral hardware and was 
>told it is possible that the drives and monitor of a PC could 
>be damaged by incorrectly written device drivers (i.e., by 
>having students write them).  Is this true?  How susceptible 
>is the IBM hardware to such damage?
>
>
>thanks in advance,
>Jim Lumpp
>

Some Hercules monochrome clone cards (not IBM, but used in IBM machines) get
toasted inadvertantly if you're not careful.  The low-level mechanics of
this are beyond my domain, but it's when you're trying to BLANK the screen
that your problems start.  Hercules (and its clones) is implemented so that
the DARKEST shade results from the HIGHEST voltage, BRIGHTEST shade from the
LOWEST voltage.  If you aren't knowledgable about what you're doing,
something so innocent as blanking the screen can toast your controller, your
display, or both.

Sadder but wiser,

Phil Miller