1-14 Technical Information
Table Section 1-7 Parallel Port Addressing and Interrupts
Starting I/O Address
Interrupt Level
Port
378
IRQ05
LPT1
278
IRQ05
LPT1 or LPT2
3BC
IRQ07
LPT1 or LPT2
378
IRQ07
LPT1
278
IRQ07
LPT1 or LPT2
3BC
IRQ07
LPT1 or LPT2
Parallel interface signals are output through the system board’s 25-pin, D-subconnector.
The connector is located at the rear of the system unit. Pin locations for the parallel
interface connector are given in Appendix A.
Serial Interface
The system has two 16C550 UART compatible serial ports (COM1 and COM2) integrated
on the I/O controller. The serial ports support the standard RS-232C interface (see Table
Section 1-8). The buffered high-speed serial ports supports transfer rates up to 19.2 KB.
These ports allow the installation of high-speed serial devices for faster data transfer rates.
I/O addresses and interrupt levels for the two channels are given Table Section 1-8. The
interrupt level is selectable via Setup to either IRQ3 or IRQ4. Software selectable base
addresses are 3F8h, 2F8h, 3E8h, and 2E8h.
NOTE:
Any interrupts used for the built-in
serial ports are not available for ISA parallel
ports.
Table Section 1-8 Serial Port Addressing and Interrupts
Starting I/O Address
Interrupt Level
Port
3F8h
IRQ04
COM1*
2F8h
IRQ03
COM2
3E8h
IRQ04
COM3
2E8h
IRQ03
COM4
* Disabled if fax/modem installed
