25 Sep
2001
25 Sep
'01
4:02 a.m.
--- Tony Duell <ard(a)p850ug1.demon.co.uk> wrote:
I am, of course, rather more excited by the ability to
display an
arbitrary pattern on a row of LEDs connected to a (static) output port
than being able to display text on a CRT screen. Because even in the
worst case I can replace said LEDs with the LED side of some
opto-isolators. And use those to control triacs or relays. And the
'Control the World' :-)
I have some programs for the PET that did just that. It was for an
energy conservation exhibit at a local science museum (COSI) in the
late 1970s. There were lights, a la "The Price is Right", in the
backdrop of the exhibit that flashed under computer control. They had
an attract mode, and several patterns while the person was playing
the energy conservation game. I don't know exactly how the hardware
was hooked up, but I know it was driven off the user port. Probably
just 8 triacs and multiple bulbs per bit to achieve chase-light effects.
At the time, I was more fascinated by the text animations done in
assembler - smooth for the day, especially compared to the stuff I
was writing at age 12 in BASIC. :-)
-ethan
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