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wickerwaka / PicoROM

An RP2040-based ROM emulator
MIT License
196 stars 18 forks source link

emulate a 16 k Bit EPROM with a standard Raspberry Pi Pico #3

Closed OE4DEA closed 8 months ago

OE4DEA commented 9 months ago

I have the use case to emulate a 16 k Bit EPROM with a standard Raspberry Pi Pico. Would this be possible by modifying the GPIOs in the system.h file or would major adjustments have to be made?

wickerwaka commented 9 months ago

It could be made to work, but a 16KBit EPROM would have a much smaller footprint since it doesn't need as many address pins. Fitting everything into that smaller footprint would be very difficult.

OE4DEA commented 9 months ago

Since I want to use the standard Raspberry Pi Pico, I don’t see any mechanical problems. My question is more about what adjustments need to be made to the software.

wickerwaka commented 8 months ago

The software assumes the presence of external buffer on the data pins, so you would need to change to code to account for that. Older versions of the code worked without it and there are defines you can change to re-enable that support, but it is untested.