Dell PowerEdge SC1420 - Manual (Page 7)

Serial Connector
Serial connectors support devices such as external modems, printers, and mice that require serial data transmission. The serial connector uses a 9-pin D-
subminiature connector.
Serial Connector Autoconfiguration
The default designation of the integrated serial connector is COM1. When you add an expansion card containing a serial connector that has the same
designation as the integrated connector, the system's autoconfiguration feature remaps (reassigns) the integrated serial connector to the next available
designation. Both the new and the remapped COM connectors share the same IRQ setting. COM1 and COM3 share IRQ4, while COM2 and COM4 share IRQ3.
Before adding a card that remaps the COM connectors, check the documentation that came with the software to make sure that the software can
accommodate the new COM connector designation.
Figure B -2 illustrates the pin numbers for the serial connector and Table B -2 defines the pin assignments for the connector.
Figure B-2. Serial Connector Pin Numbers
Table B-2. Serial Connector Pin Assignments
Parallel Connector
The integrated parallel connector, intended primarily for use by printers that require data in parallel format, uses a 25-pin D-subminiature connector on the
system's back panel. The default designation of the system's parallel connector is LPT1. If you add an expansion card containing a parallel connector
configured as LPT1 (IRQ7, I/O address 378h), use the System Setup program to remap the integrated parallel connector. See "Using the System Setup
Program" in the User's Guide.
Figure B -3 illustrates the pin numbers for the parallel connector and Table B -3 defines the pin assignments for the connector.
Figure B-3. Parallel Connector Pin Numbers
USB connector
NIC connector
NOTE: If two COM connectors share an IRQ setting, you may not be able to use them both at the same time. In addition, if you install one or more
expansion cards with serial connectors designated as COM1 and COM3, the integrated serial connector is disabled.
Pin Signal I/O Definition
1 DCD I Data carrier detect
2 SIN I Serial input
3 SOUT O Serial output
4 DTR O Data terminal ready
5 GND N/A Signal ground
6 DSR I Data set ready
7 RTS O Request to send
8 CTS I Clear to send
9 RI I Ring indicator
Shell N/A N/A Chassis ground