Common Equipment cards 35
QPC579 CPU Function
-
System Hardware-System option 51/61/71
Purpose--The
CPU Function card works in conjunction with the CPU
Interface card (QPCSSO). It contains the main CPU logic circuitry. The
CPU provides a 24-bit data bus. The CPU Function card contains a
QPC939 system ROM.
Quantity-One per CPU Module
QPC580 CPU Interface
System Hardware-System option 51/61/71
Purpose-Contains
the logic required to interface the CPU with the
external address bus and detects, identifies and isolates bus faults. Works in
conjunction with QPC579 CPU Function card.
Quantity-One
per CPU Module
QPC581 Changeover and Memory Arbitrator
System Hardware-System
option 51/61/11
Purpose-The
Changeover and Memory Arbitrator (CMA) card contrors
CPU access to the duplicated memory in dual CPU systems, automatically
disables faulty memory cards and controls CPU changeover. The CMA
switches from one CPU to the other in the event of a CPU fault.
Quantity-Two
CMA cards are required per system (one per CPU/Memory
configuration).
QPC583 Memory
System Hardware-System option 51/61/71
Purpose-Provides
768K of Random Access Memory (RAM).
Quantity-One per CPU for
System option 51/61; two
maximum per
System
option 71
Equipment identification and ordering information 553-3001-154