I did it. I wasn’t supposed to and told myself, “Some time later in life… you don’t have the space for this right now.” Alas, the more curious angels of my nature took hold and I built my first modular synthesizer out of some electrical box covers and some spare wood. But, that’s not what this post is about.
This post is about the fact that I can play that synthesizer with my Apple II Plus computer. THAT was the true breakthrough moment worth writing about in that I had not expected such an interface to so quickly materialize. But, after one night of stewing over what I had just built in my synth rack, I realized I had the know-how and a special piece of equipment that would allow it.
Pictured above is a microcontroller kit with requisite DAC (digital-to-analog converter) pack. This handy device plugs into the Apple II slot system and allows for some cool outside control of devices and apparatuses.
The DAC provided, made by now-defunct chip maker Ferranti, has an 8-bit resolution which can span 0-2.55 analog volts. THAT little spec right there was the ‘a-ha’ moment in realizing I could use that signal to play my synth through its volt/oct parameter.
Just plug in the DAC to the Apple II. Take the analog output and connect it to the synth’s volt/oct CV (control voltage) and presto—we can make a range of notes across two and a half octaves!
This concept happens to be the inaugural concept I cover in my new YouTube channel Joshua Coleman Makes. I made a pretty extensive insight into the hardware and software configurations even going so far as to list out a couple BASIC programs which we use to play the song Mary Had a Little Lamb and we use the Apple II keyboard as a musical keyboard which plays the synth.
Go check out the video for more on this fascinating concept and fascinating little modular microcontroller setup from DCP Microdevelopments. Originally, these devices were designed to run whole model train operations. Now, they’re leftover stock sitting in a warehouse in England and the people selling them are too kind! I have almost their whole range of products and they will assuredly get their own video.
Links are all provided in the video in proper YouTube fashion if you want to get your own.
Joshua Coleman 