On 22.06.2013 19:53, Kaz Kylheku wrote:
> Hi all,
> 
> There used to be a batteryless mod for the MP-1, but it's
> proving hard to find.

[ SNIP ]


> Intersil (formerly Xicor) has a unit called the X28HC64 that looks
> good. It has a 100,000 write cycle endurance, and 100 year retention.
> Someone is selling these on eBay, I've noticed.

Hello again, MP-1 slinging friends,

I now have two Xicor X2864AD-25 EEPROM chips!

One will be going into the MP-1; the other into my old Yamaha FX-500. 
(In that unit, the original SRAM chip is soldered to the board, ugh! And 
it has no MIDI OUT, so all the presets will be lost.)

Right now, I'm experimenting with backing up the MP-1 settings via MIDI 
SysEx. I'm using the MIDI-OX program for Windows to receive the data.

It is working! I've been able to save the data, then change some preset 
values, load the data, and see that the preset values have been 
restored.

Now it's time to play the game of "let's gripe about quirks in quarter 
century old Z80 firmware that nobody will ever fix".

Your current program will not change to the restored settings, until you 
do a program change to it (e.g. navigate to another program and then 
back to that one).  The settings do not propagate from memory to the 
current buffer. What the unit *should* do is go into an edited state in 
this situation, to reflect the fact that the settings on the current 
program are edited with respect to what is now in memory. Oh well; 
nobody complains when their trashed settings have just been restored!

Only version 2 ROM will do this SysEx "store all". And the dump format 
does not match any of the SysEx documentation in the Version 1 manual.  
(The Version 2 manual you can find online has no section on MIDI 
implementation for SysEx formats.) Basically, all the settings are in 
one giant SysEx message that's over 1400 bytes long.

Anyway, I got what I'm after: a backup of all the settings that I will 
(hopefully) be able to load into the new EEPROM chip if all goes well.

Wish me luck ...

P.S. anyone need an ADA MP-1 SysEx backup/restore tutorial?