6502 emulated in microcontroller (Part 4)

One step closer.  I have both the address bus (orange wires) and data bus (green wires) working and reading.  I am able to select the memory address and bank (chip select) and the data bus latches and displays the bits stored.  I still have to work through the details of using the universal shift register and timing the memory writes with it so it can read and write bytes to the bus. 

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A very photogenic breadboard!

Once I have that working I can patch the 6502 emulator to use the external ram instead of the microcontroller ram.  Turns out the method I used to select the ram, is similar to how you would do bank switching on an Apple II.  Once I have a method to dynamically map memory, I have to decide where the zero page and registers will reside,  if I use microcontroller ram,  I can’t spy on those items, but it may prove faster.  I haven’t even thought about video display or physical I/O

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