Yamaha's own MIDI definition

[Dan Gendreau]

> Do you know a person on this planet who is able to change the ROM EPROM
> or whatever firmware for a YAMAHA PFP100 electronic piano in order
> to change max velocity from the annoying 100 to 127 (like the rest of
> the world?).  I know, any sequencer can do it, as well as many little
> midi wizzard boxes...
>  but it would be better to have it right from the start.


Yeah, My Original DX-7 does the same damn thing. Unless you can find someone
who likes reverse-compiling 8-bit assembler language, you are out of luck. I
for one dont.

If I were going to do it however, I would use a little 8-pin AVR
microcontroller to translate the velocity. You should be able to do it with
no other components. Then I would mount it inside my keyboard, cut the
traces going to the existing midi-out jack and wire in the Atmel chip in
seres.

More specifically:
1) Cut the keyboard midi out signal just before the MIDI line driver. The
line driver is usually 2 inverters from a 7404 just before the midi jack.
2) Run this midi out TTL signal directly to the Atmel RxD pin
3) Run the TxD pin of the AVR back to where the keyboard midi out signal
used to connect.
4) Then you would have to track down +5V/Gnd somewhere in there. That should
be no problem.

The Translation code should be fairly simple as well. With the 8pin AVR, you
would need a software UART, but the code for that is on the Atmel web site.
The velocity translation could be done with a look-up table.

I am too busy to write this right now but you can get an Atmel development
kit(about $100) or there may be other list members who could program the
chip for you.

-Dan G.