So far I've been able to make 3 carts with no problems. I've made Gryzor/Contra. FF2e and Tetris by Tengen. Plus I've made several Atari 5200 carts so I kind of know how eproms work. But I've run into problems making The Goonies and SMB2j. On The Goonies I've downloaded several roms and none of them work. I'm using a 27c256 for the prg and a 27128a for the chr. I've used the HM03 roms and several others and the graphics are always scrambled. I've tried the H and V pads and nothing ever works. I've even tried several different cnrom boards. On the SMB2j cart the same thing happens. I'm using a 27c512 for the PRG and a 2764d for the chr. all of them are 150 ns chips. I've applied loopy's patch to the correct rom and tnines says it requires a MMC3 and am using an Image Fight donor cart. I'm about to yank my hair out over these 2 carts any help would be greatly appreciated. for the SMB2j should I try using larger chip sizes?

Welcome to the forums 82atari5200, i'm moving this one to the developer's lounge.