Dell Precision 610 - Manual (Page 91)

SLOT2_PRI Primary Intel Pentium II Xeon processor Slot 2 SEC cartridge connector
SLOT2_SEC Secondary Intel Pentium II Xeon processor
Slot 2 SEC cartridge connector
USB USB connectors
* The connector pair ISA1/PC15 share a single card-slot opening so that only one connector of the pair can be used.
NOTE: For the full name of an abbreviation or acronym used in this table, see the " Glossary ".
I/O Ports and Connectors
The I/O ports and connectors on the back panel of your computer are the gateways through which your computer system
communicates with external devices, such as a keyboard, mouse, printer, and monitor. Figure B-2 identifies the I/O ports and
connectors for your computer.
Figure B-2. I/O Ports and Connectors
Serial and Parallel Ports
The two built-in serial ports use 9-pin D-subminiature connectors on the back panel. These ports support devices such as external
modems, printers, plotters, and mice that require serial data transmission (the transmission of data one bit at a time over one line).
Most software uses the term COM (for COMmunications) plus a number to designate a serial port (for example, COM1 or COM2).
The default designations of your computer's built-in serial ports are COM1 and COM2.
The built-in parallel port uses a 25-pin D-subminiature connector on the computer's back panel. This I/O port sends data in parallel
format (where eight data bits, or one byte, are sent simultaneously over eight separate lines in a single cable). The parallel port is
used primarily for printers.
Most software uses the term LPT (for Line PrinTer) plus a number to designate a parallel port (for example, LPT1). The default
designation of your computer's built-in parallel port is LPT1.
Port designations are used, for example, in software installation procedures that include a step in which you identify the port to
which your printer is attached, thus telling your software where to send its output. (An incorrect designation prevents the printer
from printing or causes scrambled print.)
Adding an Expansion Card Containing Serial or Parallel Ports
Your computer system has an autoconfiguration capability for the serial ports. This feature lets you add an expansion card
containing a serial port that has the same designation as one of the built-in ports without having to reconfigure the card. When the
computer detects the duplicate serial port on the expansion card, it remaps (reassigns) the built-in port to the next available port