The MCS2 Hack

Warning and Disclaimer
I accept no responsibility whatsoever for any problem or damage arising from the use or misuse of this information.

The Yamaha MCS2 is a MIDI control station and, although no longer made, a very handy thing to have around the studio. It consists of a sloping metal box with pitch bend and modulation wheels, two sliders, an LCD display and ten buttons. The sliders and buttons can be assigned to transmit MIDI controller changes, particularly useful as so many modern synthesizers are knobless wonders.

The MCS2 was designed and manufactured before the XGM (Extended General MIDI) standard was defined and does not allow the assignment of the most useful new controllers:

71 Harmonic Content
72 Release Time
73 Attack Time
74 Brightness

The entire range from 64 to 95 are not assignable to the sliders. But of course this is merely a software problem. When in doubt, take the back off. Doing this reveals, among other things, a 6803 flavoured CPU and an 8K ROM. I removed the ROM from the board and fitted a DIL socket. A Dataman S3 was used to transfer the code from the old ROM to a PC for disassembly. Using the listing as a guide I was able to patch the ROM and blow a new one to fit permanently.

If you have an MCS2 and nerves of steel you can download the binary for the new ROM.

Happy Hacking!

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Revised and Verified: March 4th 1997
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