The cable technology can work exactly as described:
<Tech_Lingo> Switch the Transmit and receive wires</Tech_Lingo>

So technicaly you are covered...

But as a side note: The existance of the possiblity of doing such modification
should have great impackt on the whole socity
!!! From recorded orgasems to brainwashing

If it is possible, the machines would be illegal, sold at the black market and adictive (re: Niven's wireBrain) and this point is totaly missed in the (otherwise wonderfull) story.