I'd also suggest Bootgod's site
http://bootgod.dyndns.org:7777/
You'll notice that 10 Yard Fight is NROM-256 (because the PRG is 32K I assume) so it is ideal.
On the other hand, Baseball is an NROM game but only has a 16K PRG and is available as NROM-128 so you probably would not want to use it since you might need to do extra work to make use of it for many NROM games.
I kept some info in a word document on doing repros. Here's some info I have on NROM.
EPROM Info
NROM consist usually of a single 16KB or 32KB PRG chip and an 8KB CHR. These are 28 pin sockets, and should not require any rewiring. There is mirroring.
A 32 KB (which is a 256 Kb) chip is fine. The following chips can be added without any additional modifications or re-wiring:
27C256 (EPROM). :
http://jameco.com/wcsstore/Jameco/Produ ... /39714.pdf
AT29C256 (Flash) :
http://www.atmel.com/dyn/resources/prod ... oc0046.pdf
Modifications required:
NONE. The 27C256 (29F256) chips are essentially identical to the chips that are already on the board.
Hardware Steps:
1. De-solder the PRG and CHR chips from the donor cartridge. This is the step that will give you the most difficulty. You may damage the board, lift the traces, etc..
2. Repair anything you ruined while de-soldering. (A silver pencil can be used)
3. Since no modifications are required, just solder in two 28 pin sockets (one for the CHR and one for the PRG)
4. If mirroring needs to be switched, de-solder the H or V solder bulb on the board, and re-solder the other. (For vertical mirroring, the solder bulb should be the H). Alternatively a switch could be installed (beyond my expertise)
That should be it. Be sure to test it, and if it doesn’t work, use a Multi-meter and try to figure out if there are any shorts, or damaged connections.
Make sure the chip is full. Dont write 16K to a 32K chip. Double up the data and write all 32K.
Al