Philco model 212 computer efficiency through simultaneous operations

Abstract

An idle system element or component reduces the efficiency of its associated system by not doing the work of which it is potentially capable. An ideal system, from a hardware efficiency viewpoint, would be one in which all of the elements are working all of the time. For practical systems, a measure of its hardware efficiency may be made by taking an average of the portion of the time each element in the system is working, weighted according to the size or cost of each such element. During the development of the current Philco 2000 System (preceding the design of the Model 212 Computer), a number of design features were incorporated which produced a highly efficient system according to the above criterion. The more important of these features are: 1. The self-timing (“asynchronous”) nature of the Model 210 and 211 Computers tend to eliminate any idle time waiting for clocking pulses. 2. The computer continues to operate while input-output traffic occurs. 3. The input-output subsystem itself may have a number of independent simultaneous operations occurring. For example (depending on the prowess of the programmer) up to four tape read or write actions, on-line printing, card and/or paper tape reading and/or punching may all occur at once. 4. The more recent core storage facility is divided into four banks so that cycles may overlap each other.