3 Jun
1998
3 Jun
'98
7:05 p.m.
At 06:44 PM 6/2/98 +0100, you wrote:
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.
--------------------------------------------------------------------- O-
Uncle Roger "There is pleasure pure in being mad
roger(a)sinasohn.com that none but madmen know."
Roger Louis Sinasohn & Associates
San Francisco, California http://www.sinasohn.com/
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.