[Jürgen] then packaged that core in a Spartan-6 FPGA and placed it on a small PCB the size of the original 65C02’s 40-pin dual inline package. The FPGA is set up to access the external CPU bus ...

The prescaler described here connects to the front end of a 100-MHz frequency counter to extend ... (1.57-mm) double copper-sided printed-circuit board (PCB) that’s 7 by 2 in.

He’d like to have the 100 MHz version but the $400 difference in price puts it out of his reach. After some extensive poking around on the PCB and pouring over datasheets, he managed to reverse ...