A method of using a general-purpose computer in an on-line time sharing application

When a computer is coupled to a real time operation as in process control, the work load on the machine may fluctuate widely depending on operating conditions. External phenomena demanding action will occur essentially at random with respect to the machine. To cope with peak conditions the machine must be adequately fast, and thus will have idle time when activity is low. The use of time sharing techniques or more properly equipment sharing, allows the computer to utilize any idle time by having alternative jobs of lower priority, higher priority jobs having an interrupt facility on the machine. An engineering and programming method has been evolved of applying a computer to a process control system for on-line applications.