TRIGEM CW3S20A Canadian Product, Operation Manual

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MS-DOS uses labels to refer to the various I/O ports on your
computer. The RS232C serial port is assigned the “COM1”
(Communications port #l). Additional serial ports can be
added to your computer, which MS-DOS would label COM3,
COM4, and so on.
Parallel Ports
Unlike serial ports, parallel ports allow your computer to
communicate one entire byte at a time. Eight wires are
included in the cable to permit the transmission of each of the
eight data bits simultaneously. Extra wires are included in the
cable for control signals. Your Computer uses the industry
standard “Centronics-compatible” parallel printer port
interface.
Connecting Printers
Most, but not all, printers use the Centronics-compatible
parallel port.
To install this type of printer, connect an appropriate cable
between the parallel port connector on the rear panel of the
system motherboard in the main system unit and the input
connector on the printer. Information on the correct cable will
be found in your printer’s manual.
Note
Some printers, like the HP LaserJet, can use the RS232C
serial interface port. See the printer’s manual for complete
installation instructions.
Connecting Modems
Modems are used to connect your computer to the telephone
line. Since the electronic requirements for the transmission of
7-4 Expanding
Your
System