the combination of several general-purpose or control digital computers into a system for the purpose of raising their output or reliability. Machine integration is used to accomplish complex tasks, with input of data from peripheral points to the center, where they are processed, and some of them are stored and some are sent to designated points.
Doubling, a particular case of machine integration in which the primary machine processes the data while a standby machine is receiving preventive maintenance or working on an auxiliary program, is used for around-the-clock operation of control computers. Reliable functioning of the system is achieved by the mutual check and automatic switching (when necessary) of the circuits of the primary and standby computers. When jobs are being done on doubled machines, one machine works on the primary program and the other works on an auxiliary program. Data exchange between the computers may be done by means of software or hardware.