The one on my SA1 board is labeled 603 and it's a Microchip IC. I've seen others on various SA1 boards but am assuming they function the same and are setup different depending on the SRAM size.
So far I know that SRAM pin 26 has to tie to SA1#103 if using 256k SRAM. Doing that and lifting pin 3 on the MM1026 got me a brief intro but then not much else. Tried to look at pcb photos with 256k ram chips but they look the same being not able to see under the chips. Am I wrong assuming that that the MM1026's on a 64k SA1 cart and a 256k SA1 cart are the same and just setup differently?
Edit: I think I see what the problem is. A 256k SRAM has different pin 1 as well as 26 from a 64k chip. So that pin 1 needs to be lifted and tied somewhere to the SA1 as well?
So far I know that SRAM pin 26 has to tie to SA1#103 if using 256k SRAM. Doing that and lifting pin 3 on the MM1026 got me a brief intro but then not much else. Tried to look at pcb photos with 256k ram chips but they look the same being not able to see under the chips. Am I wrong assuming that that the MM1026's on a 64k SA1 cart and a 256k SA1 cart are the same and just setup differently?
Edit: I think I see what the problem is. A 256k SRAM has different pin 1 as well as 26 from a 64k chip. So that pin 1 needs to be lifted and tied somewhere to the SA1 as well?