Here is the timer CPLD soldered to the 12 pin header. It is not connected into the system yet. Just ready for wire-wrap at any time.
Here are the ground pins for the scope:
Here is a thing I made to debug serial communication with a scope back when I was a young’in in the ‘90’s. I wired the MAX3110E RS232 buffers to unused pins on the oscillator socket:
I wired the MAX3110E IRQ to INT on the Z-80. So all I have left to do with hardware its wire in the timer CPLD to the GPIO, SPI, and INT on the Z-80.