Yes, read the manual!
MSX Synth uses Vicent Van Dam's MIDI Framework for MIDI management. With this, you can use your MSX as a monophonic synthesizer. A very BASIC one, specially using only PSG.
It can also use MSX keys if you don't have any MIDI keyboard or sequencer. The FM drumbox included needs some kind of MIDI clock input, it won't start playing if it doesn't find any.
The Synth Core
MSX Synth evolved from a little and very Basic PSG Synth on a ROM (Beta1) to some more complex thing. The main Synth-core can load different Synth-GUIs and code to support different audio chips, so the same base can load a PSG Synth -PULSSING- and a SID Synth -SIDELINE- (included on the Beta2). It also features a little Drumbox -DRUIDISMM- that uses the FM chip from the Music Module to generate drumbox sounds and has MIDI-Out support.
The FM Drumbox worked successfully with a Korg Kaoss Pad 3 as MIDI clock source, but also sending notes to it to have 4 extra drum sounds.
Every synth has support to use presets/patches. Functions to load & save those presets to/from disk were partially implemented.
For later versions -not available nor finished yet- more features were planned, like mouse support, and more flexible GUI manager, better file browser... In the end everything is on stand-by cause lack of time and support on the project. Also, when dealing with MIDI-In, MIDI messages are handled via interrupt control and, while the screen is updated, some MIDI notes can be lost, causing some undesired behaviour. Until there is no buffered MIDI-In interface, there is no easy way to fix this, and that's discouraging.
The Synth Modules
Check the 3 beta synth modules available below!