Technical Information 1-15
Table 1-6 Parallel Port Addressing and Interrupts
Starting I/O Address
Interrupt Level
Port
378
IRQ05
LPT1
278
IRQ05
LPT1 or LPT2
3BC
IRQ05
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 and the IR
interface (see Table 1-7). 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 1-7. 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 1-7 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
** Used for IrDA data transfer
