I am trying to make a homebrew bubble bobble level hack that I made. I have SFrom chip(same as bubble bobble) and I know how to pin out the PRG eprom and have my jumper wires run, but I dont know how to run the CHR rom, its a 28 pin 27c265.

Any help would be great.

Thanks,
Dave

That's already a 28 pin chr you're replacing right? You shouldn't have to change anything. Replace the chr rom without any rewiring. Of course I'm assuming that you actually changed the graphics? If you only changed the programming, you don't have to replace the chr.

I am using a bases loaded cart it has the same chip. so I need to replace both chips. I almost have it, I have garbled graphics, but it is playable.
I think I an one wire off.

-Dave

The CHR for Bases Loaded and Bubble Bobble is 64K right?
So you'd need 27C512 as your EPROM.

Al

32k for CHR and 128k for PRG

http://www.nesdev.com/NES%20ROM%2...

It's been a while that I've worked with a 28 pin rom with anything other than an nrom, but I think that the 28 pin roms and eproms all have the same pinouts. You can double check that using the information in this document:

http://nesdev.parodius.com/rom.tx...

Using this document, you know which pin of the connector edge and which pin of the mmc1 goes to which pin of the rom (watch that many pins on the connector edge go through the mmc1 and therefore the mmc1 is where you use a multimeter to test those lines). For example, put a multimeter on pin one of the mmc1. Test to make sure that it goes to A14 on the eprom.