Is the FPGA we are using overkill for such a small amount of logic we
have to support? Yes. But with the 50AN costing only $9, and the 250E
only $18, its definatley worth it. It makes for a cheap and easy 2
layer board, simple to design in the FPGA space, as well as to
download, makes a nice simple bill of materials (one chip), and gives
us lots of logic to experiment with in the future - ie, you could add
Alex's Z80 soft card in there well. But more importantly, it gives us
the required logic to put all the soft tools, that once sat on the
bench, into the FPGA whilst we build the design. Tools such as logic
probes, logic analyzers, decoders, ROM images, etc.