[GUIDE] Make a Reprogrammable Genesis Cart

[wavebacon]

Hi,

Just wanted to experiment with this a bit. Picked up a few games to test with, but in this case I'm using NHLPA Hockey 93 as the donor cart (512Kb) and trying to use a M27C322 EPROM. The game I'm testing with is Rockman Mega World (Japan). The burns are good, verified the ROMs after burning, using a GQ-4x (latest model). Running this on a non-TMSS Genesis 1.

This board is strange; the front-facing part of the board is labeled A1/A32 on the cartridge pins. The original cart has the ROM facing towards the front of the system when inserted.

Here's some photos of what I'm working with.

http://imgur.com/a/gLaen

This is a 40-pin board, but had two pins on the far left side (ROM side) that were not connected to anything. I put a 42-pin socket in place, but noted that I would need to place 40-pin EPROMs all the way to the right (ROM side). I tested with the original ROM inserted all the way to the right and the cart works.

I tried first with the M27C322 socketed this way and wired pins 1/42/32 of the EPROM to the back side of the PCB (remember that the top/ROM side of the board is labeled A1-A32). That didn't work at all. I tried a few different variations (you can probably figure out what I tried based on the photos), but no luck.

What am I missing, or is NHLPA Hockey 93 just the wrong board to be trying this on?

I would expect to get something (corrupt graphics, etc) but when I power on the system, I get nothing but a blank screen.

Thanks for your help!

EDIT: Decided to try Wonder Boy in Monster World (USA, 1 megabyte) on M27C322; NHLPA Hockey 93 donor board. Wired only A19/A20 to B8/B9 (see photos). Still no luck, just a black screen.