System/360 -- announced in April 1964 -- represented the first basic reorganization of the electronic computer by IBM since the development of the 701 in 1952. More than any other computer development, it tied together the "loose ends" of electronic data processing and offered users a total system capability at a price they could afford.
Specifically, the new system enabled companies to integrate all of their data processing applications into a single management information system. Virtually unlimited storage and instant retrieval capabilities provided management with up-to-the-minute decision-making information.
System/360 included in its central processors 19 combinations of graduated speed and memory capacity. Incorporated with these were more than 40 types of peripheral equipment. Built-in communications capability made the system available to remote locations, regardless of distance.
A System/360 installation
Until the advent of the System/360, unlimited storage had been expensive and costly. A certain amount of reprogramming had been necessary to use added core units providing additional memory. With System/360, limited storage capacity was no longer an obstacle to the maximum use of a computer. System/360 processors provided a central memory capacity of from 8,000 to 524,000 characters. Additional low-cost storage of up to eight million characters was available with any of the larger configurations.
With System/360, it was no longer necessary to match a user's problem to a specific piece of equipment because of differences in machine design and problem-solving capacity. System/360's units could be combined in an almost infinite variety of ways so that the system was literally tailored to a customer's job.
The built-in communications capability of System/360 allowed the user to greatly increase the scope of computer usefulness. Up to 248 data transmission terminals could communicate with the computer simultaneously -- even when it was busy on a batch processing job.
The System/360 also ended the distinction between commercial and scientific computers. Each System/360 processing unit had the ability to process work through small binary, decimal or floating point arithmetic centers. This meant that the same System/360 configuration could handle commercial work, scientific work or a combination of the two, with equal effectiveness.
Starting with the System/360, the mainframe's circuits were closely combined on half-inch ceramic modules. With the new Solid Logic Technology (SLT), the smallest processor of System/360, out of the five originally announced with that computer family, could perform 33,000 additions a second; the largest, three quarters of a million. Statistically, an SLT module averaged 33 million hours before failure. SLT provided not only a technological building block for the System/360, it also solidified IBM's commitment to supplying much of its own component technology. In addition to developing this technology, IBM also built the equipment to make and test it.