Technical Information 1-13
Parallel Interface
The system has a 25-pin parallel port on the system board. Specifications for this port
conform to the IBM-PC standards.
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 the Setup.
Interrupt levels for the parallel port are given in Table Section 1-11. Software selectable
base addresses are 3BCh, 378h, and 278h.
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 shown in Appendix A.
NOTE: Any interrupts used for the built-in par-
allel port is not available for ISA parallel ports.
Table Section 1-11 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
*Default for parallel port
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