HP 9000 Series 743, Service Handbook, Page: 34 / 165

Functional Description
Overview
2-4
CPU Circuit
The HP PA-RISC 7100 CPU chip is located beneath the heat sink in the center of the
board.
Boot ROM Circuit
The Boot ROM circuits:
• Start the CPU functions
• Self-test the board computer’s main circuits
• Search for and boot an operating system
• Manage the internal interface configurations
An EEPROM stores information for:
• Internal interface configurations
• LAN ID number
NOTE: The workstation’s LAN ID number’s last 6 characters are labeled
on the EEPROM. The first group of digits are typically 080009. If
the system board or EEPROM is replaced, the system administrator
uses the complete LAN ID number to reconfigure the networked
system.
Should replacement be necessary for these parts, the customer is responsible for providing
replacement custom OEM ROMs.
A Program Timer Module contains the system clock. All timing is based on the system
clock. The Boot ROM circuits involve several important boot and configuration functions.
The Model 743 has two LEDs; one red, and one green, that indicate various system func-
tions. Table 2-1 shows the meaning for each LED.