Editing Null modem (section)

== Origins ==
Originally, the RS-232 standard was developed and used for [[teleprinter]] machines which could communicate with each other over phone lines. Each teleprinter would be physically connected to its modem via an RS-232 connection and the modems could call each other to establish a remote connection between the teleprinters. If a user wished to connect two teleprinters directly without modems (null modem) then they would crosslink the connections. The term ''null modem'' may also refer to the cable or adapter itself as well as the connection method.<ref name="lammertbies">{{cite web |author=Lammert Bies |url=http://www.lammertbies.nl/comm/info/RS-232_null_modem.html |title=RS232 serial null modem cable wiring and tutorial |publisher=lammertbies.nl |access-date=2013-12-26}}</ref> Null modem cables were a popular method for transferring data between the early personal computers from the 1980s to the early 1990s.