Dell 6100 - I;O Ports and Connectors

I/O Ports and Connectors B-1
Appendix B
I/O Ports and Connectors
T
his appendix provides specific information about the
input/output (I/O) ports and connectors on the back panel
of the computer.
The I/O ports and connectors on the back panel of the
computer are the gateways through which the computer
system communicates with external devices, such as a
keyboard, mouse, printer, and monitor. Figure B-1 identi-
fies the I/O ports and connectors for your system.
S
erial 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 transmis-
sion 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 com-
puter’s built-in serial ports are COM1 and COM2. COM1
is the right connector; COM2 is on the left.
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 the computer’s built-in paral-
lel 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 a printer is attached, thus
telling the software where to send its output. (An incor-
rect designation prevents the printer from printing or
causes scrambled print.)
Figure B-1. I/O Ports and Connectors
Adding an Expansion Card Containing
Serial or Parallel Ports
The 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
mouse
COM1
LPT1
VGA
keyboard
COM2