I was about to put Mega Man 4 Minus Infinity MMC5 on Hardware.
I thought of using two 27c4001 chips rather than 27c801 because I got plenty of them lying around.
I searched the Internet about this and came across a method to put up to six chips into SNES cart using '139 demultiplexer, and I also found out that NES game Protoboards used '139 logic to put up to 4x128kb eproms on a cart.
Unfortunately, there is no concrete information on how to connect the demultiplexer.
I have a theory on how to connect it and I need assurance before I start soldering it on the PCB:
'139 Pin# -> connected to
#1 to /CE on the PCB
#2 to Pin 66 of MMC5 (A19)
#4 to /CE of PRG Chip#1
#5 to /CE of PRG Chip#2
#8 to GND
#16 to +5
Thanks in advance.
I thought of using two 27c4001 chips rather than 27c801 because I got plenty of them lying around.
I searched the Internet about this and came across a method to put up to six chips into SNES cart using '139 demultiplexer, and I also found out that NES game Protoboards used '139 logic to put up to 4x128kb eproms on a cart.
Unfortunately, there is no concrete information on how to connect the demultiplexer.
I have a theory on how to connect it and I need assurance before I start soldering it on the PCB:
'139 Pin# -> connected to
#1 to /CE on the PCB
#2 to Pin 66 of MMC5 (A19)
#4 to /CE of PRG Chip#1
#5 to /CE of PRG Chip#2
#8 to GND
#16 to +5
Thanks in advance.