Design Expansion of the D17B Computer Input/Output Facility for General Purpose Applications

摘要

In an effort to determine the extent to which the capabilities of the D17B computer can be applied to general-purpose information processing tasks, the report presents the results of a study of the input/output structure of the machine. A technique is presented which enables the processor to transfer data to and from peripheral equipment on a program-controlled basis and at a rate which approaches the execution rate of the processor. The technique employs a bus-structured I/O system which also controls program loading and verification operations to achieve the 800 char/sec maximum loading rate of the computer. Another technique is presented which applies certain specialized functions of the D17B to directly link high-speed peripheral equipment with the memory for output transfers. By using this partial direct-memory access method, a transfer rate of 12.8K words/sec can be achieved. (Modified author abstract)