At 11:35 PM 7/22/99 +0100, Brian J. Beesley wrote:
>Back more or less to topic -
Oh, this is very much on topic!
> when I was a computing neophyte, a
>quarter of a century ago, I was told a story by an engineer working
>for a major mainframe supplier. For a laugh, the development team
>wired up a loudspeaker (presumably through a buffer and amplifier of
>some sort) to one of the bits in a CPU shift register. (This was
>easily done in the days when everything was discrete components!)
>The trick was then to code your program so that it performed to
>specification, but, by insertion of extra instructions to tweak this
>particular bit at suitable times, played interesting tunes whilst
>doing so!
Alex Hurwitz loves this story. They did just that on the SWAC. It
was captured for prosperity in the film 'Magnetic Monster'. I once
made some MPegs and put them on the wwweb. I wonder if they are
still there? Alex says the sounds in the movie were produced by LL
tests.
I recall the CDC 3150 was so wired from the factory. There was
even a volume control on the operator's console. Probably a very
helpful debug tool as you could not see the console when you were
across the room with your head inside a 32 KB memory bank the size
of a refrigerator, poking away looking for faulty a core memory.
--Luke
_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
