Vector Imagery

[Philip Pemberton]

Don Y wrote:
> Sound card sure seems easier!  :>
> Build a WAV file and just have it "play" endlessly.

I'd have thought the AC coupling hardware would have caused problems with 
that, and you'll have a maximum frequency limit of about 20kHz due to the 
low-pass filters on most sound cards.
And I doubt the parallel port would be fast enough. Best plan would be a pair 
of DACs, a counter and a 16-bit EPROM (or a pair of 8-bits). Program the ROM 
with the pattern data, hook up a display and have fun. Could even add a few 
more ROMs and have colour output and/or intensity control as well.

Heck, the simplest DAC is a bank of 20 resistors (R-2R ladder). Cheap too - a 
penny a resistor, total cost of 20 British New Pence. I don't think ADI or 
Maxim have anything cheaper...

-- 
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