Lee Jones wrote:

> In the original Macintosh system, Apple's designers used AMD
> 26LS30 driver and 26LS32 receiver.  The driver's power supplies
> were +5V (Vcc) and -5V (Vee) [volume III, page 26, figure 4.
> Diagram of Serial Ports].  So the RS422 TxD- output pin was
> very close to the letter of the EIA/TIA-232 voltages at the
> transmitter pin and certainly met the voltage requirements of
> EIA/TIA-232 at the receiver pin with any reasonable cable.

  Excellent explanation.  Obviously Ben's problems are anything *but*
the RS-232 interface as long as the Warp-13 has an RS-232 interface
chip like the PP1, and the cable is connected as it is supposed.
--
  Cheers,
        Paul B.