MIDI-CV converters (was: Building my first synth...)

Christopher List Christopher_List at sonymusic.com
Tue Feb 6 09:33:53 CET 1996

>     I just had an idea - I have an old XT laying around, with an original 
>     MPU-401 in it. If I made a D/A circuit board, and it was controlled by 
>     the PC hardware, it should be possible to develop the code on the PC 
>     and run it to make a very high-powered MIDI-to-CV controller. The D/A 
>     could be an 8- or 16-bit discrete R-2R ladder, driving an big analog 
>     mux into a bunch of S & H's, with some gate latches as well. It would 
>     probably be easy to go to sixteen or thirty-two analog voltages. The 
>     software could do all of the demux scanning probably, reducing the 
>     hardware requirements. There could be a graphic user interface for 
>     setting up the channels etc. This all could probably be done in 
>     something easy like Visual Basic or Visual C....

Sounds brilliant, Gene! I don't know why, with all these companies (OK, so 
there's only 1 or 2 of 'em) making MIDI to CV converters, someone hasn't 
already done this! In fact (total brain storm here) a sound card with an 
amplifier could be used as a one-channel midi-CV converter - Left for the gate, 
right for the CV... - Sorry, I'm getting crazy... 

Back to the original topic. The cool thing would be to have a utility type 
program that could run on your PC or Mac which commandeers the parallel port 
and one of your MIDI output ports. The utility would have a little patch-bay 
kinda setup thing, like all device drivers, and could route the midi data from 
one (or more?) midi out ports to the various CV channels. - Then you could just 
route your sequencing software to the out-port assigned to the converter - or 
use midi mapper to route an input port to the converter output port. I bet the 
software would be totally easy to write and could have all kinds of features 
that would be a real drag to put into a hardware-based Midi-CV converter. 

Now THIS is a seriously marketable product! 

Unfortunately, I've never done any device driver or serial / parallel port 
coding. Although I've seen some decent books on the subject.

I gotta go on some kind of "Unlimited Power" wheat-grass juice diet plan or 
something so that I can get by on only 3 hours of sleep a night and work on all 
these projects (sigh)...


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