decided he could live without the echo (the board you are referring to didn't exist then).

What no echo on Centaur?? Shame!  I would strongly recommend getting the after market board.  The cable is not hard to make up if it is missing, as long as you have got the right S&T board in the machine.  There is another mod floating around to adapt the SIA to use a different chip, but I have not got around to trying it out as my SIA is still alive...

cheers
Ian