Adding MIDI To A Very Old Drum Machine

Long before drum machines played samples from an SD card or EPROM, drum sounds were analog – just filtered waveforms and noise. To the modern eye, these are very primitive machines, but for [Andrew], they’re the inspiration for this brilliant hack.

[Andrew] took a Roland CR-68 drum machine from 1978 and added MIDI input with the help of a PIC microcontroller. Not wanting to modify the look of the machine, [Andrew] programmed the PIC to watch the START/STOP button when the the unit is powered on. If the button is held down, the PIC enters it’s programming mode, where the sounds from the CR-68 can be mapped to an individual note on a MIDI controller. There’s no mention if the TRIGGER IN is queried by the PIC to modify the tempo of the preset patterns, but we assume that would be a relatively trivial implementation. Still, very impressive for a machine made 4 years before MIDI.

We love [Andrew]’s work, and we’re happy for any future owner that he documented how to use his device (and cleverly taped that to the bottom of the drum machine). It’s very nice to see old drum machines being used for more than doorstops after their samples have been recorded. Check out the video of [Andrew]’s walk through after the break.


8 thoughts on “Adding MIDI To A Very Old Drum Machine

  1. not bad

    @alf, you could do a midi out but it would just be those buttons and knobs as controllers, you wouldn’t be sending the sounds or anything like that

    what’s useful about his hack is that you can write your own patterns and send them to the drum machine

  2. I’m wondering about turning analog output into MIDI… lots of software plugins are capable of this, but I’d be curious how it’s done with MC’s, and not the button inputs but the actual audio.

  3. “Long before drum machines played samples from an SD card or EPROM…”

    ^ That isn’t entirely accurate, within 2 years of the release of the CR-68/78, drum machines were using samples. The Linn LM-1 Drum Computer was playing samples off chip in 1980, then came the Oberheim DMX in 1981, and the E-Mu Drumulator in 1983.

    While the iconic Roland TR-808 (released in 1980 shortly after the LM-1) used fully synthesized drum sounds, by 1984 all the Roland TR-series machines used samples for at least some of their sounds, usually the hi-hats and cymbals.

  4. @octel, I think @ALF is wanting to generate MIDI from audio and not send audio-by-way-of-MIDI. He is right in that these plugins exist, but you may have to settle for 1-note polyphony.

    I can’t think of any good reason to do this.

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