1A Processor: Control System

The 1A Processor control system, coupled with program, call, and auxiliary memory, is an independent, stand-alone processor with full operational and maintenance capability. It provides for execution of the processor and system program, automatic system maintenance actions, manual control and monitoring, and interfaces to memory, network, and external systems. This processor is an outgrowth of previous Bell System switching processors. Although it contains many similar or modified features, the new processor offers significant improvements over its predecessors. In comparison with the No. 1 ESS processor, 1 several major new features and improvements are provided--for example, four to eight times faster instruction execution, writable program memory, greatly expanded program and call memory size capability, and auxiliary memory with autonomous transfer to and from program and call memory (direct memory access). These advancements are achieved while maintaining compatibility with the No. 1 ESS network and programs. The control system consists of the central controls (cos), communication buses, and the man-machine interface and control. The manmachine interface and control includes the master control console (MCC), 135