Not much to it. Got it at goodwill, found a header on it with serial output at 115200 TTL. I *think* I've found the input, but it hasn't been sensitive to input yet. What it does print out, however, is this:

MP620 MaskRom V002

SDRAM 8Mx16/16Mx16 Load NAND 
NAND ID : 000000D3
AP found
AP size : 0038AA10
AP check sum : FC394CD8
load OK
../source/main.c 1159
Enable PLL1 spread spectrum
CPU Initiale to 96MHz
-I- CPU Initial to 0077083f

dwMainProcSize 00527000
Network buffer pool 8094f000 00072000
disp buffer1 80773980 000ed800
disp buffer2 80861180 000ed800
Heap buffer  809c0980 0063f680
!!!Free_CacheWin 0