Tuesday, January 29, 2013

GenMDM Polyphonic Handling App

// GDAY M8s //

Normally, the GenMDM is monophonic i.e. each MIDI channel is directly mapped to a chip voice (1 - 6 for FM, 7 - 10 for PSG). As a result, each MIDI channel can only play one note at a time, as a single chip voice can only make one sound at a time.

Tonight I made a simple polyphonic handler for both the FM chip and the PSG chip of the SEGA Mega Drive. 

Usage is very simple: 
• Create a MIDI track in Live / Logic / ProTools / whatever
• Sequence a chord on this track with up to 6 notes
• Send the output of this track along channel 1 of a virtual MIDI bus (e.g. IAC MIDI bus 1 for OS X)
• In the GENMDM_POLY app, choose the same virtual MIDI bus as the input
• In the GENMDM_POLY app, choose the GenMDM as the output
• The level of polyphony for the FM and PSG chips are set by the user (2 - 6 voices for the FM and 2 - 3 voice for the PSG)
• Chords will automatically routed to GenMDM channels 1 - 6 without any effort whatsoever
• If you gave a stuck note, use the "KILL NOTES" button to stop it
• A chord with up to six notes should be routed to the FM chip via MIDI channel 1 (channels 2 - 6 should not be used)
• A chord with up to three notes should be routed to the PSG chip via MIDI channel 7 (channels 7 - 10 should not be used)



Zach said...

Thanks! This is great.

When I play a chord, the third note is always silent. I have tried it with "Special Ch. 3" checked and unchecked, no sound either way. Am I doing something wrong?