Firmware

DarkAKI firmware

If You bought SimpleStereo board as a kit, or wish to upgrade the AKI firmware You need to get PIC programmer - any will do that is up to the task
I personally use Willem combined with WinPic800 software.
 

SimpleStereo board being programmed.
 

Another thing that would be handy is the adapter - as You know, PIC chip on SimpleStereo board is placed under first POKEY chip, and since it is SMT device it would be hard or economically unjustified to program it off circuit (ZIF socket for SO-18 chips are very expensive), thus it is programmed once the board is completly assembled.

schematics of adapter

Firmware v2.0 rev A2 (RECOMMENDED!)
Firmware v2.0 rev A3

The Gal chip

Gal comes programmed, since i have required adapter. The chip is copy-protected, but if something fails, and You'll damage it You may get programmed replacement for $4, or request JEDEC file to program it Yourself

Hope You'll never have to resort to replacing this chip, but if You do, please use Hot-Air soldering station to remove the one that failed, or You'll likely end up with damaged PCB