Hmm, I wonder if it's a timer or interrupt issue. TMNT is SM511 vs Top Gun's SM510, but I think the opcodes are all the same. Maybe the reset vector's different?
I transcribed the ROM from the patent and visually dumped it, but did not electronically dump it, so there could well be some bad bits.
Sorry, I numbered the baddies opposite the digits: baddies have #1 on the left, digits have #1 on the right.
The All Clear button grounds the ACL input to do a hardware reset.
