nesdev.org

It could be done with 8 4M chips, but it'll be a bigger mess. Really the Game Doctor copiers or another copier is the way to go if you want to be economical. this isn't for economics. i'm interested in making real carts to provide them to a certain group of people at the lowest possible price (part...

TmEE wrote:The 2XY040 is a 4Mbit chip not 4MByte. You will need to get 32Mbits/4Mbytes in total, so you'd need 8 of those buggers
I'd locate a 29F032 chip and a TSOP adaptor, much less hassling.

do you think it can be done with 4 8Mb chips instead? or is a 29F032 really the best way?

All I can say is that Terranigma uses a SHVC-1J3M board. It shouldn't be very usefull. If you can get such a board and change the mask ROM (and maybe change the pinouts as well) you should be done, but unfortuantely it's probably impossible to find 4MBx8 EPROMs. You'll have to deal with a stack of ...