<html><head></head><body>Yes, because of the expo curve it required non-standard (not R-2R) values. They sold the part for experimenters to play with. I wired up my own QuASH on vector board, and at different times used an 8085, 8080A and a PDP-11 to control it.<br>
<br>
As someone else mentioned the PAiA software could also do intelligent voice assignment and ADSR.<br>
<br>
-Dave<br><br><div class="gmail_quote">On January 9, 2018 7:00:46 PM PST, KA4HJH <ka4hjh@gmail.com> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<pre class="k9mail"><br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"> On Jan 9, 2018, at 9:08 PM, David Manley <dlmanley@sonic.net> wrote:<br /> <br /> I can confirm the DAC was exponential, it used a custom resistor network from ??? (insert major US manufacturer of resistor networks - can't recall right now it was in a light blue ceramic package). From memory there's nothing to the QuASH but a 8-bit register to latch the micro writes plus an analog switch demuxing the 'DAC' output to simple capacitor plus TL0xx output buffers. I may still have Simonton's published lab notes somewhere.<br /></blockquote><br /><br />I recall something about a "laser trimmed" resistor network.<br /><br /><br />Terry Bowman, KA4HJH<br />"The Mac Doctor"<br /><br /><br /><hr /><br />Synth-diy mailing list<br />Synth-diy@synth-diy.org<br /><a href="http://synth-diy.org/mailman/listinfo/synth-diy">http://synth-diy.org/mailman/listinfo/synth-diy</a><br /><br /></pre></blockquote></div></body></html>