Hi, I was thinking about making my own SNES repro multicart (just for fun). If I use an M29f033 chip (32Mb capacity), I can toggle the A21 line to switch between the top and bottom 16Mb banks to select from 2 different games, that much I understand. But, how about if I want to put on my chip 2x 8Mb games and 1x 16Mb game? Would that be easy to implement? I was thinking to use a binary counter that has its clock pin tied to the reset button on the console (pin 26 of the cart connector, I believe). If I disconnect A20 and A21 of the rom from the cart PCB and attach them to Q0 and Q1 of my counter, respectively, then I can select between 8Mb chunks of the rom, right? Like this: Code: Counter: 0 1 2 3 A20: 0 1 0 1 A21: 0 0 1 1 8Mb chunk: 1st 2nd 3rd 4th This sequence would just cycle. However, when I want to play the 16Mb rom (let's say it's in the lower half of the memory) I don't want the binary counter to assert (neither low nor high) A20 as the SNES needs control over it in order to access the whole rom. Is there an easy way to make this work? Hopefully I've made my problem clear enough. Thanks EDIT - could I use a 157 logic chip to select if the SNES or my counter gets control of the A20 line?