Gemini FM

Github Page

   Part of why I got interested in the MSX line of computers was because of it's wide array of sound modules. Most of these are supported in very few if any games at all, due to developers reasonably wanting to target the least common denominator setup most MSX users have. When they do spring for an add-on, it's usually one of the more common ones. Gemini FM is music software that's meant to allow you to write a song for one of the more common add-ons, the FM-PAC, and have it also be able to play back with enhanced sound on the much rarer Yamaha SFG, which contains the OPM chip famously used in all the coolest arcade machines and some of the coolest computers. Yamaha sold MSXes with this add-on bundled and their CX series computers were the only MSX models available in the United States without resorting to an importer. And yet, I can count the games that support the SFG FM Synthesizer Unit on one hand because it's so uncommon compared to the FM-PAC, SCC, or the stock PSG built into every MSX computer. My hope is that if more people adopt this music engine in their games, they will be able to breathe new life into CX series computers and aftermarket SFG clones while also allowing the much wider audience who owns FM-PAC compatible devices to enjoy FM sound in their games.

   The main tool used to make music for Gemini FM is actually hosted right here on this website. Click here to access the Gemini FM MIDI Converter, which allows you to compose music for the replayer with your favorite MIDI editor and then upload it here to get GFM song data.

   The same music data being played twice, once on an FM-PAC OPLL on the left and once on an SFG OPM on the right.


Github Page

   Growing up I played the clarinet. I've always wanted to learn how to play the keyboard, but the idiom of a wind instrument will always be more natural to me. When I found out about Electronic Wind Instruments, or "EWIs," I was ecstatic... until I saw how how much even the cheap ones go for! Surely one could be built for cheaper, it's just a few buttons and a brain to figure out what note to play and to play it, right? A man by the name of Gordon Good actually put together a great guide on how to build a simple and cheap one, and following that I built my own using the Teensy Audio Library to give it some rudamentary FM sythesis abilities. The end result worked and sounded pretty good, but wasn't particularly ergonomic and became almost impossible to play for me after an injury. A third attempt fared a little in the ergonomics department but was still a but too unweildy, so this project ultimately ended and I purchased a warbl ewi that I am now very happy with. While I wasn't the one to make it happen, there are many more affordable EWI options now than there were when I started, so I can't complain! From a code perspective this is just about done, only thing I wasn't happy with was a bit of noise when the volume dropped too fast, but otherwise if you wanna take a crack using the firmware be my guest.

   The Mark 1 was a school project hobbled together with the parts I had. Pretty ugly, but you gotta start somewhere!

   The Mark 2 was a bit better, had much more sophisticated sound generation with knobs to control simple 2-OP FM synthesis parameters and fingerings spanning D4 to F#6 chromatically. Heavier than it looks and awkward to play, but a solid proof of concept and a real taste of the potential of the instrument.

   The Mark 3 was designed to remove any and all pressure from my hands, but the arcade buttons ended up being a bit too stiff and the thing had a nasty habit of falling apart. It's a shame because it'd be fun to play this massive wire-laden lug live!