null modem

1 definition found

null modem - Free On-line Dictionary of Computing (26 May 2007) :

  null modem
  
     <communications, hardware> A cable, especially an EIA-232
     cable, for connecting serial ports on two computers directly,
     rather than via modems.  Since, according to the
     specification, both computers should transmit on pin three of
     their EIA-232 connectors and receive on pin two, a null modem
     cable needs to connect one computer's pin two to the other's
     pin three and vice versa.  It also needs to have male
     connectors at both ends (again, according to the
     specification).
  
     (1996-05-17)