1-26 Technical Information
PCI Local Bus
The industry-standard PCI-bus is a highly-integrated I/O interface that offers the highest
performance local bus available for the Pentium processor. The PCI-bus supports burst
modes that send large chunks of data across the bus, allowing fast displays of high-
resolution images.
The high-bandwidth PCI-bus eliminates the data bottleneck found in traditional systems,
maintains maximum performance at high clock speeds, and provides a clear upgrade path
to future technologies. PCI expansion slot connector pin assignments are provided in
Appendix B.
PCI Auto Configuration
The system comes with a PCI auto configuration utility that operates in conjunction with
the system’s Setup utility. The utilities automatically configure interrupts, DMA channels,
I/O space, and other parameters to allow addition of PCI boards with minimal intervention.
Parallel Interface
The I/O controller provides a programmable bi-directional printer port that can can be
configured as EPP, ECP, or PS/2 compatible.
The BIOS has automatic EISA printer port sensing. If the BIOS detects an EISA 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 1-7. 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 B.
The printer port base address and interrupt request can be independently disabled. It is the
responsibility of the system BIOS to ensure that the base address or interrupt request line
used by a parallel port is not used by the EISA bus (or conflicts will result).
Table Section 1-7 Parallel Port Addressing and Interrupts
Starting I/O Address
Interrupt Level
Port
278H
IRQ05 or 7
LPT1
378H*
IRQ05 or 7 (default)
LPT1 or LPT2
*Default for parallel port