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In pictures: The (mostly) cool history of the IBM ...
But it was in 1964 that IBM began what many would consider the first true series of mainframes, the IBM 360. IBM at the time said the System 360 includes in its central processors 19 combinations of graduated speed and memory capacity. Incorporated with these are more than 40 types of peripheral equipment that store information and enter it into and retrieve it from the computer. Built-in communications capability makes System/360 available to remote terminals, regardless of distance. The equipment is supported by programs that enable System/360 to schedule its own activities for non-stop computing that makes most efficient use of system capabilities.
In pictures: The (mostly) cool history of the IBM mainframe