Potential add-on board?

[mikej]

Hi.
I think the CM3 module will run very nicely as a 68060.

"The Computer Module has exactly the same connections as a Raspberry PI... so yes, people are pretty much limited to using serial connectors to talk to the beast."

Not quite. It has a lot more IO pins on the edge connector, and these can be used as a local bus interface, similar to the original 68K.

[mikej]

EDIT: You do get some extra GPIO pins, but only 45 in total. Not enough to do to a full processor with on a pin to pin basis... but you are right in saying it does have extra pins.

Some potential, but not as much as you might think... Hmmm. Definitely something to mull over.

The GPIO pins are also connected to BCM ARM peripherals, for example i2c/spi etc.
SMI is one of these peripherals designed to connect to multiplexed address/data buses.
It can spit out some data at high speed, and a simple FPGA can then act as an interface to the 68K socket.

Dave has done some work here to replace a 6502
https://github.com/hoglet67/PiTubeDirect

My application, using the CM3 as a CPU in an FPGA system is quite a bit simpler as I have more flexibility in the interface timing.

I'll post more on the fpgaarcade.com forum as I make progress.