Specifications
Hardware Configuration
2–25
2.9.1 SCSI Interface Configuration
Configure the SCSI interface according to your system’s needs. This is covered in the following
paragraphs.
Interrupt Request Assignment
The SCSI interface is a PCI peripheral and is assigned to the PCI INTA interrupt. No user setup is
required
Active Terminators
The SCSI interface uses “active terminators” for the SCSI bus. Active terminators draw less current than
330/220 ohm terminators (standard for non-UltraSCSI interfaces), are less susceptible to noise, and are
required for the high data transfer rates of UltraSCSI..
Only the SCSI devices on each end of the SCSI bus should be terminated.
External Termination Power Option
You can power external SCSI terminations from the Little Board/P5i. A jumper option, W3, connects
power (+5V) to the SCSI bus TERMPWR signal (J9, pin 26). The board includes a Schottky protection
diode to prevent damage to the board by current flowing from the SCSI bus.
The default jumpering of W3 is open; that is, termination power is not normally supplied by the
Little Board/P5i.
SCSI ID
Every SCSI device must be configured for a specific SCSI bus ID, between 0 and 7. Set disk drive and
other SCSI target device IDs to 0 – 6. The SCSI BIOS automatically detects SCSI devices on the bus and
logs them in at boot time.
Enabling or Disabling the SCSI Disk Interface
Disable or enable the SCSI interface using jumper W17. Set the jumper as shown in Figure 2–6.
Figure 2–6 SCSI Enable/Disable Jumper
Details about the SCSI interface, installing a SCSI hard disk, and using SETUP to configure the SCSI
interface are provided in Chapter 3.
2.10 BYTE-WIDE SOCKETS
The Little Board/P5i has a 32-pin onboard byte-wide memory socket, designated S0. This socket can
accept a wide variety of EPROM, Flash EPROM, SRAM, and nonvolatile RAM (NOVRAM) devices.
Battery backup power can be connected to S0 using a jumper option to make a standard SRAM “non-
volatile.”
You can use a memory device installed in the byte-wide socket for a variety of purposes:
Simple program storage
BIOS extension