Multiple Input-Output Links in Computer Systems

An algorithm is developed for the analysis and design of computing systems having a multiplicity of concurrent and independent information sources and a lesser number of input channels to the processing elements of a digital computer; the input-output links work simultaneously with the processing and computing elements of the system. Utilizing this algorithm, such problems pertaining to the amount of hardware and the interconnection of its components can be resolved. For an optimum system design, its parameters are subject to two major criteria, i.e., the amount of information transmitted to the central processing elements per unit time, and the degree of overlapping of input output operations with computing (or other processing operations) that can be attained. Part I of this paper is devoted to information sources of the sequential access, serial-by-character (or-bit) transmission class. Magnetic tape units are specifically dealt with. With minor modifications the method is applicable to other information sources of the same class. In Part I, three fundamental system configurations are discussed and results of computations are summarized. In Part II, information sources of the quasi-random and random access class are investigated within the framework established in Part I. Disk files were selected as a specific representative of the quasi-random and random access information sources.