two CPUs enables the state of one CPU to be continuously compared to that of the other CPU on a cycle by cycle basis. Any discrepancy between the two CPUs results in maintenance circuitry determining which CPU is at fault and activity to change to the same CPU. A Program Store is dedicated to each CPU and is a memory for the program instructions required by that CPU for processing calls, maintenance and for administrative tasks. The PS associated with the other CPU contains identical program instructions. A Data Store is dedicated with each CPU and contains dynamic information on a per-call basis, as well as customer data and office-specific settings. The other CPU is also associated with its own DS containing duplicate data. The Central Message Controller controls the flow of messages between the other units of the CCC and prioritizes them for the Network Message Controller (NMC) in the various Network Modules (NM), or the Input/Output Controller (IOC). Both CPUs have access to either CMC which share the message load to the Line Modules or peripherals. The original NT40 based CCC was replaced by the compatible DMS SuperNode in 1987. DMS SuperNode The DMS SuperNode Computing Module was first based on the Motorola 68020 Central Processing Unit (CPU) and then upgraded to the Motorola 68030. In the early 1990s it was further upgraded to use the Motorola 88100 and 88110 Reduced Instruction Set Computing (RISC) CPUs. This RISC version of the SuperNode Computing Module was known as the BRISC (BNR Reduced Instruction Set Computing) CPU. With the BRISC CPU the DMS SuperNode had a processing capacity of 1,500,000 call attempts per hour. DMS SuperNode featured increased processing capacity across a distributed architecture allowing for the development of new features and services. Each of the elements of the DMS SuperNode uses a common SuperNode CPU hardware design differing only in the software used to control them. The SuperNode consists of two main elements: DMS Core and DMS Bus. DMS Core provides the main computing facility and is made up of the Compute Module, System Load Module and a Message Controller. The Compute Module contains redundant SuperNode CPUs to handle call processing and maintenance functions and, like the NT40 core, can operate in a synchronized mode with its mate. The System Load Module contains all the necessary software for every element of the DMS switch and also provides file system