Synthesix turns your MSX into a modular MIDI synthesizer.
I presented the project today on the MSX Fair Nijmegen. For those of you who weren’t there, let me post the text from the flyer:
Synthesix
MSX Modular MIDI Synthesizer
Highlights
Polyphonic
Multi-timbral
Multi-channel
Modular architecture
MSX-MIDI / Philips MIDI support
Chip support
SCC, SCC-I*, PSG*, OPL1*, OPLL*, OPL4*
Components
Envelopes (AR, AD, ADSR*)
LFO (triangle, saw*, sine*, pulse*, sequence*)
Key trigger & gate
Wavetables
Pitch bend
MIDI clock*
Multiplication / addition operators
Modular architecture
Instantiate any number of components and hook them up in any way you like. Component inputs and outputs can be connected in user-defined configurations.
Designed for real time MIDI control with a controller or an external sequencer.
* Currently not implemented yet
There is no release version yet (sorry). It still needs a lot of UI work and extended chip support. Right now the only way to define a program is in assembly code 
. But most of the core architecture is in place. When it is released it will be free and open source.
I’ll try to make a Youtube video sometime soon showing off some of the features.
Feel free to post questions, ideas, etc.
It was low on my priority list (main interest is trying to a game) but a few years back I thought it would be very cool to be able to connect a few MSX computers to a PC and use them as synthesizers within pc software like cubase. Other than mixing msx sound with sounds from softsynths or digital audio/samples, I thought of other possiblilities like stereo, better sound through more available voices (by using more than one MSX) and maybe some crazy stuff like using 5 or 7 msx with FMPAC+SCC in a "surround sound" setup 
I hope you resolved the lot of problems I got in MSXsynth (as syn nicely pointed, I'm more or less working on it, but very slowly cause I focus more on videogames) when you send too many notes in a short time to the MSX via MIDI and you still need to dump something to VRAM.
