Control Data Cyber 170 State Hardware Reference Manual page 22

Major
System Component Descriptions
Major System Component Descriptions
The major system components include:
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Central processor (CP)
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Central memory (CM)
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~nput/output unit (IOU)
r System console
The remainder of the chapter provides brief descriptions of the major system
components. The descriptions refer to the computer system block diagram
(figure 1 - 2 ) .
Central Processor (CP)
The central processor (CP) hardware (figure 1-2) consists of the following.
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Instruction section.
Registers.
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Execution section.
Cache memory.
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Addressing section.
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Central memory control.
The CP is isolated from the IOU and, therefore, is able to carry on computation
or character manipulation unencumbered by I/O requirements.
Instruction Section
The instruction section directs the arithmetic and manipulative functions for
instruction execution. The instruction section prefetches instruction words
from memory and disassembles them into instructions..