Yea i suspect the CIA chips deal with the ports and they do get fried if you fit a really old PC to the parallel port ( ie non bi directional)...
Don`t worry about that though... :-D
i remember that you could expect a theoretical 2 Mbytes/s from the parallel port.
i myself have a port jr. attached to the clock-port on my 1200 and that can go up to 230kb /sec (or so)