Technical data

Theory of Operation 3-9
3.2 FRU-Level Operation
This section describes the operation of the major FRUs in the system. Refer to the ap-
propriate block diagram (Figure 3-1 through Figure 3-5) as you read the descriptions
of these FRUs. Refer to Chapter 4 for diagnostic procedures and to Chapter 5 for re
-
moval and replacement procedures.
3.2.1 CPU Board
The CPU board controls the program flow in the system, and is the host for the follow
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ing system components:
• Memory boards
• SCSI devices
• Network and HP-IB boards
• Graphics controller board or graphics processor interface board
The following lists show the most important elements of the CPU board’s hardware.
An asterisk (*) next to some items denotes hardware that is not available on the Model
400dl.
• The emulator board, which includes the following components:
– The MC68030 Microprocessor (the system’s CPU)
– The MC68882 Floating-Point Coprocessor (FPU)
• Boot ROM and EEPROM (for configuration data storage)
• The Utility Interface, which includes the following:
– The system interrupt controller
– Three full-duplex programmable ports for Serial I/O (SIO)
– One full-duplex programmable serial port for the Apollo keyboard
• The Integrated Interface Controllers, which include the following controllers:
– HP-HIL
– LAN (IEEE 8013 with ThinLAN and AUI connections)