This one in via Plutoniq9:
"*I'm reposting this from the sequential yahoogroup for AH'ers. It was a fascinating project to work with Bob on. He truly is a master of the art! What i think is fantastic is that this project has taken a very "crippled" SCI instrument with limited use and turned it into a synth that has mass potential now. It has been a long process and I applaud Bob for taking the initiative and devoting a lot of his free time to make this possible. Without his efforts this would have probably never been realized.;
In addition to what is listed below, we were able to identify and fix a major bug in the Max having to do with enabling velocity and simultaneous midi cc control.
Also, I have performed this mod alongside Bob (there were a few revision), and I can vouch that it is flawlessly implemented and feels like a whole new instrument to work with.
---------------------------------------------------------------------------------------------------------------------
Attn Sequential Max owners: With ideas and encouragement from Ryan Palmer
>(AKA Plutoniq9), I have developed a new version of
the Max firmware which has the following features:
1) 100 downloadable programs (Max had 20 that could be downloaded)
2) Storage for ~3200 notes in two songs (Max could store about 500)
3) Unison mode (Max did not support Unison mode)
4) Battery-backed storage of downloadable programs and songs
5) MIDI chan and a few other parameters are also non-volatile
6) Three sets of programs in EPROM, loadable on request:
a) Max orig 80 programs plus Six Trak Unison programs
b) Six Trak orig 100 programs
c) Multitrak orig 100 programs, without chorus and velocity sens parameters
7) Current voice parameters, including any CC changes, can be stored in program
#99
8) Program #99 can be copied to any other program.
[One quick follow up.
7) & 8) listed below addresses the Max's limited patch creation abilities. Now, using any standard midi cc controller you can create & save onboard any patches you create without the use of a computer. Prior, patch creation could be done only by a sysex sound dump TO the max (which of course would be lost once you switched off the unit). The max always had cc parameter support, however any changes to the current patch made via CC's would not be reflected when you sent a sysex sound dump to the Midi out. Shitty huh?]
9) MIDI receive buffer increased from 64 bytes to 128 bytes
[doubles the midi receive buffer from 64-bytes to 128-bytes. It doesn't sound like much, but it enables a ton more simultaneous cc control messages to be sent to the max without choking it up. Previously, more than four cc messages sent to the max while sending midi note data would lock up the voices. Also with unison now able to be enabled, that number dropped down to one! With the larger midi buffer, I haven't yet been able to lock it up in either poly or unison mode (I tried 5-6 simultaneous cc's in unison with no problem).]
To support these features, the memory chips in the Max need to be upgraded.
This requires good soldering skills. Chips need to be removed from the board, a
few traces must be cut, and a few wires need to be added.
The following parts are needed:
27C256 (new code EPROM, Flash memory chip can also be used)
32Kx8 NVRAM DS1230Y-150+ (installed in place of U12)
24-pin machined pin IC socket for NVRAM
28-pin IC socket for EPROM
Two BAT48 Schottky diodes
1K 1/4W resistor
>
>If anyone is interested in trying this mod in their Max,
>please contact me and I will provide more information and instructions. If
there is enough interest, I can make a small PC bd which will simplify the mod,
but add about $10 to the cost.
>
>I am not selling anything, except possibly the pc boards, but will help anyone
who is interested and has the necessary skills to perform the mod.
>
>Bob Grieb
>"
Update: additional details in
this post.
