On Thu, 4 Jun 1998, Uncle Roger wrote:
It was just two precision resistor networks
connected through
CMOS drivers to the address lines of the C64. One network for
the lower 8 address lines and one for the upper 8. When the two
networks were connected to the XY inputs of a oscilloscope, you
had a 256 by 256 pixel display of where in memory the 6510
was executing.
That wasn't the first time that trick had been published in Byte. Steve
Ciarcia used it in one of his earlier Circuit Cellar articles. But it's a
very useful trick, and deserves to be shown again.
There was a guy who was selling videos of (I guess) the same sort of thing
for the Mac at the first VCF. Sam can probably get you info. I thought it
was neat, but being perpetually broke, didn't go for it.
Well, the guy at VCF mapped the address, data and register lines of a
Pentium (or 486, can't remember) to an oscilloscope. The scope would jump
all over the place based on what was being done inside the CPU.
I ended up with a copy of the video. It's cool to watch for about the
first 10 seconds and then you've seen it all. The video goes on for about
an hour showing the operator of a windows PC do different things. Yeeha.
Sam Alternate e-mail: dastar(a)siconic.com
-------------------------------------------------------------------------------
Ever onward.
September 26 & 27...Vintage Computer Festival 2
See
http://www.siconic.com/vcf for details!
[Last web page update: 05/30/98]