info-mac@uw-beaver (01/01/85)
From: LEVITT%MIT-OZ@MIT-MC.ARPA I've played with 2 different homebrew versions of a Mac/MIDI interface: 1) Dan Kottke of Apple built a tiny, special cable assembly, including a crystal, diodes, and resistors, which successfully communicated MIDI signals with a Yamaha DX-7 synthesizer with the right serial chip software. Andy Hertzfeld of Apple helped with the software driver. It didn't seem to work with the Roland Jupiter 6 or other synthesizers I tried it on; I don't know if there was a flaw in Kottke's all-passive design, or a problem with that particular kludge assembly. (It required power from one of the external disk drive pins!) 2) Bob Rees, a local friend, did something similar with a more complicated circuit (and presumably less "inside" information). It also worked with a DX-7. Months ago I heard some manufacturer was interested in his design. But I'm not aware of a commercial Mac/MIDI interface yet either; I'm disappointed and impatient.