I've found an old UART transceiver I made a long time ago and put that into the project. I had to bring in a few more procedures to support it. I haven't checked it out yet, but it's connected to the databus.

I also changed how I access individual bits. I don't want a whole register just to read a single bit. So I have one driver which drives the upper 7 bits low on all bit register reads. So when I read my carry bit, it will only take a single flip-flop instead. I'll have to pick out chips to do this next.

I also put the program counter readback buffers on the bus. I've been thinking about how to do software functions, and I don't see an easy way to return from a function call without first storing the program counter in a memory location (maybe software memory stack). Two more chips...