This section 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 1 identifies the I/O ports and connectors
for your system.
Figure 1. I/O Ports and Connectors
 |
| 1 |
Mouse connector |
| 2 |
Keyboard connector |
| 3 |
USB connectors (2) |
| 4 |
NIC connector |
| 5 |
Serial port 1 connector |
| 6 |
Parallel port connector |
| 7 |
Serial port 2 connector |
| 8 |
Video connector |
|
The two integrated 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 integrated serial ports are COM1 and COM2. COM1 is the bottom connector; COM2
is on the top.
The integrated 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
integrated 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 a printer is
attached, thus telling the 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
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 as one of the integrated ports, without having to reconfigure the card. When
the computer detects the duplicate serial port on the expansion card, it remaps
(reassigns) the integrated port to the next available port designation.
Both the new and the remapped COM ports share the same interrupt request (IRQ) setting,
as follows:
COM1, COM3: IRQ4 (shared setting)
COM2, COM4: IRQ3 (shared setting)
These COM ports have the following I/O address settings:
COM1: 3F8h
COM2: 2F8h
COM3: 3E8h
COM4: 2E8h
For example, if you add an internal modem card with a port configured as COM1, the
computer then sees logical COM1 as the address on the modem card. It automatically remaps
the integrated serial port that was designated as COM1 to COM3, which shares the COM1 IRQ
setting. (Note that when you have two COM ports sharing an IRQ setting, you can use either
port as necessary but you may not be able to use them both at the same time.) If you
install one or more expansion cards with serial ports designated as COM1 and COM3, the
corresponding integrated serial port is disabled.
Before adding a card that remaps the COM ports, check the documentation that
accompanied your software to make sure that the software can be mapped to the new COM port
designation.
To avoid autoconfiguration, you may be able to reset jumpers on the expansion card so
that the card's port designation changes to the next available COM number, leaving the
designation for the integrated port as is. Alternatively, you can disable the integrated
ports through the System Setup program. The documentation for your expansion card should
provide the card's default I/O address and allowable IRQ settings. It should also provide
instructions for readdressing the port and changing the IRQ setting, if necessary.
If you add an expansion card containing, for example a parallel port configured
as LPT1 (IRQ7, I/O address 378h), you must go into the system setup
program to remap the integrated parallel port.
For general information on how your operating system handles serial and parallel ports,
and for more detailed command procedures, see your operating system documentation.
If you reconfigure your hardware, you may need pin number and signal information for
the parallel port connector. Figure 3 illustrates the pin numbers
for the parallel port connector and defines the pin assignments and interface signals for
the parallel port connector.
If you reconfigure your hardware, you may need pin number and signal information for
the keyboard connector. Figure 4 illustrates the pin numbers for
the keyboard connector and defines the pin assignments and interface signals for the
keyboard connector.
Figure 4. Pin Numbers for the Keyboard Connector
 |
| Pin |
Signal |
I/O |
Definition |
| 1 |
KBDATA |
I/O |
Keyboard data |
| 2 |
NC |
N/A |
No connection |
| 3 |
GND |
N/A |
Signal ground |
| 4 |
FVcc |
N/A |
Fused supply voltage |
| 5 |
KBCLK |
I/O |
Keyboard clock |
| 6 |
NC |
N/A |
No connection |
| Shell |
N/A |
N/A |
Chassis ground |
|
Mouse Connector
If you reconfigure your hardware, you may need pin number and signal
information for the mouse connector. Figure 5 illustrates the pin
numbers for the mouse connector, and defines the pin assignments and interface signals for
the mouse connector.
Figure 5. Pin Numbers for the Mouse
Connector
 |
| Pin |
Signal |
I/O |
Definition |
| 1 |
MFDATA |
I/O |
Mouse
data |
| 2 |
NC |
N/A |
No
connection |
| 3 |
GND |
N/A |
Signal
ground |
| 4 |
FVcc |
N/A |
Fused
supply voltage |
| 5 |
MFCLK |
I/O |
Mouse
clock |
| 6 |
NC |
N/A |
No
connection |
| Shell |
N/A |
N/A |
Chassis
ground |
|
The system uses a 15-pin high-density D-subminiature connector on the back panel for
attaching a video graphics array (VGA)-compatible monitor to your computer. The video
circuitry on the system board synchronizes the signals that drive the red, green, and blue
electron guns in the monitor.
 |
NOTE: Installing a video card automatically disables
the system's integrated video subsystem. |
If you reconfigure your hardware, you may need pin number and signal information for
the video connector. Figure 6 illustrates the pin numbers for the
video connector, and defines the pin assignments and interface signals for the video
connector.
Figure 6. Pin Numbers for the Video Connector
 |
| Pin |
Signal |
I/O |
Definition |
| 1 |
RED |
O |
Red
video |
| 2 |
GREEN |
O |
Green
video |
| 3 |
BLUE |
O |
Blue
video |
| 4 |
NC |
N/A |
No
connection |
| 5-8, 10 |
GND |
N/A |
Signal
ground |
| 9 |
VCC |
N/A |
Vcc |
| 11 |
NC |
N/A |
No
connection |
| 12 |
DDC data out |
O |
Monitor
detect data |
| 13 |
HSYNC |
O |
Horizontal
synchronization |
| 14 |
VSYNC |
O |
Vertical
synchronization |
| 15 |
DDC clock out |
O |
Monitor
detect clock |
| Shell |
N/A |
N/A |
Chassis
ground |
|
Your system contains two Universal Serial Bus (USB)
connectors for attaching USB-compliant devices. USB devices are typically peripherals such
as mice, printers, keyboards, and computer speakers.
NOTICE: Do
not attach a USB device or a combination of USB devices that draw a maximum current over
500 milliamperes (mA) per channel or +5 volts (V). Attaching devices that exceed this
threshold may cause the USB ports to shut down. See the documentation that accompanied the
USB devices for their maximum current ratings.
If you reconfigure your hardware, you may need pin number and signal information for
the USB connectors. Figure 7 illustrates the USB connector, and
defines the pin assignments and interface signals for the USB connector.
Figure 7. USB Connector
 |
| Pin |
Signal |
I/O |
Definition |
| 1 |
Vcc |
N/A |
Supply voltage |
| 2 |
DATA |
I |
Data in |
| 3 |
+DATA |
O |
Data out |
| 4 |
GND |
N/A |
Signal ground |
|
Your system has an integrated 10/100–megabit-per-second (Mbps) network interface
controller (NIC). The NIC provides all the functions of a separate network expansion card
and supports both the 10BASE-T and 100BASE-TX Ethernet standards.
The NIC includes a Wakeup On LAN feature that enables the computer to be started by a
special local area network (LAN) signal from a server management console. Wakeup On LAN
provides remote computer setup, software downloading and installation, file updates, and
asset tracking after hours and on weekends when LAN traffic is typically at a minimum.
Network Cable Requirements
Your computer's RJ45 NIC connector is designed for attaching an unshielded twisted pair
(UTP) Ethernet cable equipped with standard RJ45-compatible plugs. Press one end of the
UTP cable into the NIC connector until the plug snaps securely into place. Connect the
other end of the cable to an RJ45 jack wall plate or to an RJ45 port on a UTP concentrator
or hub, depending on your network configuration. Observe the following cabling
restrictions for 10BASE-T and 100BASE-TX networks.
NOTICE: To avoid line interference, voice and data lines must be in separate
sheaths.
- For 10BASE-T networks, use Category 3 or greater wiring and connectors.
- For 100BASE-TX networks, use Category 5 or greater wiring and connectors.
- The maximum cable run length (from a workstation to a concentrator) is 328 feet (ft)
(100 meters [m]).
- For 10BASE-T networks, the maximum number of daisy-chained concentrators on one network
segment is four.
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