I'm very new to the chiptmusic scene. I'm creating a new game for Vectrex and it just so happens that music is the key element. It's a dance-mat type game... for Vectrex (no really!): https://github.com/Phillrb/Dance-Dance-Vec. You will of course need to make your own dance mat though!
Cut a long story short; the Vectrex shares the same sound chip as the Atari-ST, Spectrum and Amstrad (YM2149F or AY-3-8910). I originally looked into YM6 files and AY files and then discovered that most people make SNDH files. I then found a large online archive: http://sndh.atari.org/. My plan is to create a converter that converts SNDH files into the source code I need for Vectrex.
The REAL question... how do you compose SNDH files on a Mac (running OS X 10.10)?