Xref: utzoo rec.humor:19749 comp.misc:5438
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From: mlloyd@maths.tcd.ie (Michael Lloyd)
Newsgroups: rec.humor,comp.misc
Subject: Re: Looking for Computer Folklore
Message-ID: <669@maths.tcd.ie>
Date: 10 Mar 89 18:56:52 GMT
References: <864@jato.Jpl.Nasa.Gov> <2047@tank.uchicago.edu> <36549@vax1.tcd.ie>
Reply-To: mlloyd@maths.tcd.ie (Michael Lloyd)
Organization: Maths Dept., Trinity College, Dublin
Lines: 32

In article <36549@vax1.tcd.ie> belld@vax1.tcd.ie writes:
>
>		I remember hearing that an early version of the Commodore
>Pet would catch fire if certain addresses had certain contents. Something
>about the clock being forced to run at too high a speed. (Can anyone confirm/
>deny this?)
>-- 

Nah, Nah, Nah - yer got it all wrong, squire.
The story goes (and this one is true) that the Commodore Pet early versions
not only had integral monitors (all one big box, y'know) but the software
had a _certain_ amount of control over the screen.  This meant that, if you
REALLY knew what you were doing you could
  (i) disable the refresh interrupt where the raster beam (the thing that
      scans down a monitor at huge speeds to make the picture) retraces to
      the top left corner
  (ii) stop the beam in its place

result: one VERY BRIGHT SPOT in the middle of the screen somewhere, which if
        left will burn clean through the monitor, causing irreprable damage.

This contradicted the first law of such machines: nothing you can type at the
keyboard could do any PHYSICAL damage to the machine.  I wonder if anyone
else has examples of this sort of behaviour?  (not wishing to drag out
an already overlong theme ;-) )

Mike.

Mike Lloyd, Dept of Statistics, |
Trinity College, Dublin,        |      "COGITO, ERGO CHICO & ZEPPO"
Ireland.                        |          Tonio K.
(mlloyd@maths.tcd.ie)           |