Hi,
hmm most NULL modem cable are incompatible with the amiga's i/o poorts.
I build my own cable and i used TWINS to comunicate with amiga's, this is quite fast and realy easy to use from BOTH sides, but only works under dos on the peecee side.
I'm using ethernet at the moment , got my self an ariadneII card for my a4000 and some cheep PCMCIA cards for my a600 en 1200.