> Are you sure? I have run FastWire on a 4.77MHz XT. FastWire is one of those
> fast file transfer programs that uses the parallel port to talk between pcs.
> It is definitely bidirectional.
>

G'day, FastWire does it by trickery. The special cable connects 5 of the data
 out bits on one end to the 5 handshake inputs at the
other. It looks like bidirectional comms but it is realy a 5 bit full duplex
 link. Interlink does the same thing.

The data bits on the origanal parallel printer port were unidirectional. Some of
 the handshake lines were bidirectional. Some of
the later parallel printer ports have bidirectional data bits.

Cliff Rogers   (Computer Technician)  email  cliffrogers@usa.net
Absolute Computers Pty. Ltd. Cairns, Queensland, Australia.