18 Jul
2001
18 Jul
'01
5:08 p.m.
> I have always reassured my programming students
that nothing that they
> accidentally enter through the keyboard of their computers would actually
> DAMAGE the computer. One wiseguy said, "I entered a Pepsi."
On Wed,
18 Jul 2001, Tony Duell wrote:
More seriously, on a PC with an IBM MDA card and IBM
5151 monitor, what
about a series of port write (output) commands that reprogram the 6845 to
generate a strange horizontal sync frequency. That can let the magic
smoke out of the monitor horizontal output stage.
In "PC-POWER", later renamed "Peeks and Pokes", Brett Salter (who did
the
"Periscope" hardware assisted debugger) had some serious problems when he
demo'd (in BOTH meanings!) the video modes, including some unacceptable
ones.
That is why I had included the word "accidentally" - to cover the few
possible ways of causing damage, that would not occur without extra effort
or intent.
Some modern motherboards will let you "flash" the BIOS, ... potentially
leaving you with a dead machine and no way to boot up to fix it other than
unsoldering and replacing the old BIOS.
And, although it does not cause any HARDWARE damage, you can always erase
the hard disk, and/or wipe the CMOS, so that it needs to be reconfigured.
--
Grumpy Ol' Fred cisin(a)xenosoft.com