1-12 Technical Information
Parallel Interface
The system has a 25-pin parallel bidirectional enhanced parallel port on the system board.
Port specifications conform to the IBM-PC standards. The port supports Enhanced
Capabilities Port (ECP) and Enhanced Parallel Port (EPP) modes for devices that require
ECP or EPP protocols. The protocols allow high-speed bidirectional transfer over a parallel
port and increase parallel port functionality by supporting more devices.
The BIOS has automatic ISA printer port sensing. If the BIOS detects an ISA printer port
mapped to the same address, the built-in printer port is disabled. The BIOS also sets the
first parallel interface port it finds as LPT1 and the second port it finds as LPT2. The
interrupt is selected to either IRQ5 or IRQ7 via Setup. Software selectable base addresses
are 3BCh, 378h, and 278h.
I/O addresses and interrupts for the parallel port are given in Table Section 1-5.
NOTE:
Any interrupts used for the built-in
parallel port are not available for ISA parallel
ports.
Table Section 1-5 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 Section 1-6). 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.
