1 Jul
2006
1 Jul
'06
2 p.m.
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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