Hi Bill,
Yes it all fits together. There is a problem with the FP on top of the SIO though that I haven't tracked down. The FP works fine but there is a segment 'e' I think it is, that is not lit on all characters. I think its a shorted bit on the SIO board, although they all checked out on with an ohm meter when I was testing before plugging it. The CPU and SIO board work fine, as does the FP even when using the bit banging I/O port on the FP with the CPM.
Paul
Paul Bigwood