Although not exactly what you are doing, but I do see some parallels.
I purchased? a working 8594E without TG or external I/O.
My plans are:
Operate the 8594 from a Raspberry PI and FPGA. Interfaced through a cheap tablet.
Build a TG RF board with current components interfaced? by SPI.
Clips only tell part of the story, for instance addressing is by GAL without the truth tables.? The ROMs seem to be completely undocumented.
