Different approach to servicing the bus

[+Andrew Davie]

I was thinking about a different method to servicing the bus;

feed the address pins (on the breakout board for the '2600) through some sort of latch/gate, so that when ANY of those pins change we see "1" and otherwise 0.

Then we feed that result 0/1 to a pin on the STM board.

Then we can setup a pin-based interrupt on the STM -- it will trigger when there's an address change, and it can service the bus and exit.

At this point we have the STM free to do anything else. No more idle loop.