If you're comfortable that the 40-pin stamp would meet all other
criteria, namely has enough I/O and you feel able to program it in
BASIC, I wouldn't worry about the module. We can cook up an
interface between stamp I/O and opto-22.

Thanks for the offer. I ordered the stock items with the 16 IO stamp so I
can write and debug the program while down here. I have one of the four DC
gear motor units running. Should keep me busy for a few months.

Karl