Renovation of a tried and tested commercial design. Not my own design!
So far I only have a photograph of this board!
I recently saw one for sale on eBay, for $995. After postage, VAT, import duty, it will cost even more (as I found out with my 80C188 board!). Alas, I can't afford it. The vendor says the price is firm.
This was not a best seller.
I suspect the PAL chips are a lot more complex than the 68008 or 68020 designs. They must interface the CPU's 16-bit data bus to the 8-bit STEbus. There is a 74LS646 instead of the usual 74LS245 bus data buffer.
This project is shelved until I can get one at an affordable price....