Ever had your N64 memory pak battery die and lose all your precious saves from your childhood games? Or purchase an aftermarket pak only for it to arrive broken? I have, which is why I designed my own N64 memory pak. I used an FM28V020 FRAM IC which does not require a battery to retain the saves and according to the datasheet it will last 150 years! Most FRAM modded paks I see use parts harvested from an original nintendo memory pak so instead I designed my own pcb so I can build the whole device with off-shelf purchased parts.
The pcb will even fit perfectly in an original nintendo memory pak shell in that case that you want to swap them. I modeled the memory pak shell to be 3D printed.
The memory size is 256KB, which is the same size as the original pak. Due to the memory bank size, it is not possible to use a larger memory. Some aftermarket paks that advertise extra memory, quite literally have two memory ICs inside with a switch to activate either chip.
I think this has turned out to be a good product that is needed in the market flooded with over priced FRAM modded paks so I will be selling them on ebay. Get yourself a reliable memory pak that will keep its saves for generations!