USRobotics V.34 - Manual (Page 96)

COURIER HIGH SPEED MODEMS
B-2 Summaries and Tables
THE RS-232 INTERFACE
DESCRIPTION
The RS-232 interface is a standard developed by the Electronic
Industries Association (EIA). It defines the signals and voltages
used when data is exchanged between a computer or terminal
and a modem or serial printer. Data is transmitted between the
devices via a cable with 25-pin, 9-pin, 8-pin or custom-built
connectors.
The modem takes a DB-25P (25-pin plug, or male) connector at
one end of the cable. Computer equipment varies, however.
Check the serial port at the rear of your machine, which may be
labeled
SERIAL , COMM PORT , or some other term (e.g., RS-232). If
there are no labels, review your machine documentation to find
out which is the serial port. (There may be more than one.)
Don't use a port marked
PARALLEL , PRINTER or AUX .
The physical serial port on the computer or terminal will be
either a socket (female) or plug (male) that typically accom-
modates 25 or 9 pins. For example, the port on the IBM PC,
PC/XT and most compatibles requires a DB-25S (socket) con-
nector, while the port on the IBM PC/AT and some compatibles
requires a DB-9S connector. Apple computers require a DB-
25P, DB-9P or, more typically, an 8-pin round plug connector.
Check your computer documentation or with your computer
dealer.