Have made a start on the board. Was only going to do the minimum to work on the Timing PAL (TPAL) programming. But was in the zone so kept going until I ran out of IC sockets and .1uf Caps. Another order for DigiKey 🫤

The EPROMs ( sorry FLASH Memory) are programmed with the original code. As for the TPAL I managed to work out the clock divisors, but the TPAL does a lot more than that. It uses a 3-bit synchronous counter driven by 30 MHz and 15 MHz clock inputs to generate critical DRAM timing signals, such as /RAS, /CASL, /CASU, and ROW/COL. Not something I can work out easily so will have to wait for people smarter than me to work that one out.  

Till then I'll be optimistic and continue soldering bits in. Have a good de-soldering gun as back up. 😋