picogus VS pigus

are the PIO blocks wide enough to handle an ISA bus? Or are you using a shift register or another port on the pico to interface with the bus?

edit:: looking at the schematic it looks like you have the address/data pins multiplexed on an 8-bit port: https://github.com/polpo/picogus/blob/main/hw/PicoGUS-schema...

Curious if you did the HW design first, or SW design first, or how you came up with this particular solution.

That one... you can find there: https://github.com/polpo/picogus/

The projects I mention here are not clones themselves but ever cheaper PCB prototypes and microcontrollers make it a fantastic time to create hardware for old systems (ISA). Enjoy!

There is PicoGUS [0], a Gravis Ultrasound emulation, a Raspi Pico based PCMCIA WLAN card [1], EDO/FPM RAM modules [2], "Snark Barker", a soundblaster 1.0 clone [3]...

If you want more electronics stuff, I suggest you follow the creators of these on Twitter.

[0] https://github.com/polpo/picogus

[1] https://www.yyzkevin.com/pcmcia-pico-w-card/

[2] https://twitter.com/0xCats/status/1524708654913662977

[3] https://github.com/schlae/snark-barker

I had some very successful experiments with bit banging ISA on a Raspberry Pi 3 and 4 a while ago: https://github.com/polpo/pigus I quickly moved over to a Raspberry Pi Pico because it's much better suited to such things. You need more than a couple I/O pins, though... to do real ISA (i.e., not LPC) right, you need more GPIOs than what the Pi gives you. But muxing the data/address lines is enough to give you back what you need.