Abstract: A computer system includes a central processing unit, a main memory unit and a master controller unit, which master controller interconnects the processing unit and the memory. The processing unit utilizes virtual addresses and generates virtual address to access the memory. However, the memory is accessed using real addresses. Thus, the master controller performs the required translating function for the interoperability of the processor and memory and does so without requiring instructions from the processor. This represents a significant decrease in processor overhead.

Abstract: The disclosure relates to a computer system having a central processing unit and a main memory for storage of information in binary form. A master control unit is provided for performing individual and selected range checking and range conversion by reading of information from an internal memory of the master controlled unit which contains a data Descriptor Table with a table entry for each individually accessible data element in the main memory with two elements of each Descriptor Table entry assigned for range check and conversion purposes. One of the elements permits one of the extreme limits of a value range of a data element in the main memory associated with a data Descriptor Table entry to be determined and the second element allows the number of values in the value range of the associated data element to be determined.

Abstract: Message switching organization for exchanging data messages between function or signalling units within the memory of a processor controlled telecommunications system. Each such function unit has its own program and its own data storage, and the program of a unit has access only to the data storage of its own unit. Messages transmitted between units are of two types, those including information regarding the destination unit address and those omitting destination unit address. Each unit has a message handler area with its own program and data storage, the message handler acting to supply destination unit address information for messages of the second type.