Here, if LoROM, I think you forgot to add bridge for pin 15 <-> pin 4LittleRain wrote: ↑Fri Jul 17, 2020 2:36 pmHey no problem at all man, lidnariq answered the other questions, but I'll answer the rest.
2- I am using the S8050, but any NPN will be fine, could also use an N-channel mosfet as well.
3- The jumpers are solder bridges, so if I don't want to mount the switch, I can just solder one of the connections together.
Good luck with your board!
And if you are using the M27C322, I would make an adapter board as well, it is extremely helpful, I made one on my own with perf board and it was pure hell to solder. Next time I order boards I will definitely be ordering one.
Edit: As for adding HiRom capabilities, instead of having 2 decoders, just add solder bridges to the decoders pins. I just whipped this up quickly, I believe it should work.
HiRomDecoder.png
Hi and Lo Rom Decoder.png
And if you don't want SRAM, just remove battery, SRAM and transistor circuit. Do not even need to make a separate board, just don't place those components. Here is a schematic, you can compare with my original.
LoRom_NoSram.png
Maybe something like that:

Oh, yeah... You are right here I dont need that:

Its will be better like that:

And all so...
Your "REGLED" net is connected to nothing on your schema.

Normally, pin 48 (BA7) and pin 57 (CPUCLK) of SNES cartridge are dont need to be connected:

