After a long time away from this project, I finally had some time to come back to it and wire up my serial port!  I am now able to transmit data from the TG6502 to my host computer at 19200 baud.  The classic "Hello, world!" message:

I have not yet connected the receive line.  That'll be the next step.  Thus far I have only verified that the ROM, VIA and ACIA are working.  I haven't yet tested the RAM, so once I can verify that I can send and receive data correctly, I will write some simple memory test routines.

Here's how things look at the moment: