An 4mb variant of my 8mb flashcard , will cost a little less , it use an mx29lv320 4mb flashchip instead of an 8mb mx29lv640 , and the 2 position switch for EX mode not present.

sram size configurable to 2kb , 8kb or 32kb with the switch at top

it use 3.3v parts , so an complete level shifing is presents with voltage divider and bidirectional bss138.

designed to be smt assembled with the attached BOM and pick and place file

the pic12f need to be programmed with supercic .hex , i designed an adaptator for easily and fast program it via a slot cartridge and an eprom programmer:

https://www.pcbway.com/project/shareproject/SNES_pic12f_supercic_flashing_adaptator_fe9b1172.html

compatible with sanni card reader , flash them at 5v.

need order pcb in ENIG ( minimum ) and 1.2mm thickness

NOT 1.6mm VERY IMPORTANT

the board is 4 layers

L1=TopLayer

L2=InnerLayer1

L3=InnerLayer2

L4=BottomLayer