6502 emulated in microcontroller (Part 3)

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After successfully getting address lookup, and read/writes to work using a common SPI like bus I decided to go a little further.

I removed the 8K x 8 chip and added two 32kb chips.  I am using the decoder chip on the last unused address bus line to do chip enable between the two chips allowing it to address 64kb by automatically switching to the second bank,  however later on I can leverage additional bank switching by hooking up the last two address lines to open pins on the arduino.  I put this together so I can use eeproms or other alternatives based on my configurable mapping.

I even got a rudimentary multitasking system experiment going on by swapping zero page and register address pages when memory is swapped, relying on the microcontroller to swap banks.

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