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Abstract

The most generally useful combination of analog and digital equipment possible is a hybrid installation which includes a general purpose digital computer and a general purpose analog computer, with a flexible interface between the two machines. This thesis contains a detailed description of a hybrid interface designed to link a DEC PDP-9 digital computer to an EAI Pace 231R-V analog computer and other equipment. Double buffering is provided on digital output channels from the PDP-9, including those servicing digital-to-analog (D/A) converters, loading from buffer registers to output registers can be commanded from either the analog or the digital side of the interface. A sixteen channel multiplexer with a settling time of less than two microseconds has been designed and is employed with a twelve bit analog-to-digital (A/D) converter for high speed data transfers. The digital voltmeter and signal selector in the analog computer are operated together to provide a low speed 540-point multiplexer-A/D converter. The signal selector, mode controls, and servo-set potentiometers of the analog computer can be operated on command from the PDP-9. Individual mode control of each of sixteen integrators is also provided.