DAD, The C. Operating System The design and implementation of the C. operating system, DAD, is described in detail. This system is designed for the Control Data 3600 using a large drum backing store and is intended to allow the integration of a remote console (display) subsystem into a conventional job stack environment. The use of the drums, the buffering of input and output on slow peripherals, and the execution of normal job stack work are described. The display subsystem is described only as it integrates into the rest of the system. The techniques found useful in the development of DAD are given, and an assessment is made of the validity of various design decisions. Performance figures based on several months of operation are tabulated. CACM September, 1967 Austin, B. J. Holden, T. S. Hudson, R. H. CA670910 JB February 27, 1978 2:58 PM 1534 5 1534 1534 5 1534 1534 5 1534