Hardware Reference
In-Depth Information
If you need more serial ports than your system has as standard, or if your system did not
include a serial port, you can purchase single-port or multiport serial port adapter cards.
Notethatcard-basedmodemsmayalsoincorporateabuilt-inserialportonthecardaspart
of the modem circuitry (except controller-less software modems).
Figure 14.23
shows the
standard9-pinconnectorusedwithmostmodernexternalserialports.
Figure14.24
shows
the original standard 25-pin version.
Figure 14.23
AT-style 9-pin serial port connector specifications.
Figure 14.24
Standard 25-pin serial port connector specifications.
