IBM System/360 year 1964

1964
IBM System/360 System/360 Designer IBM Bits 32-bit Introduced 1964 Design CISC Type Register-Register Register-Memory Memory-Memory Encoding Variable (2, 4 or 6 bytes long) Branching Condition code, indexing, counting Endianness Big Page size N/A, except for 360/67 Open Yes Registers General purpose 16× 32-bit Floating point 4× 64-bit History of IBM mainframes, 1952–present Market name 700/7000 series System/360 System/370 System/390 zSeries 900, 800, 990, and 890 System z9 System z10 zEnterprise System (z196, zEC12, z13) Architecture System/360 System/370 S/370-XA ESA/370 ESA/390 z/Architecture v t e The IBM System/360 (S/360) was a mainframe computer system family announced by IBM on April 7, 1964, and delivered between 1965 and 1978.[1] It was the first family of computers designed to cover the complete range of applications, from small to large, both commercial and scientific. The design made a clear distinction between architecture and implementation, allowing IBM to release a suite of compatible designs at different prices. All but the incompatible model 44 and the most expensive systems used microcode to implement the instruction set, which featured 8-bit byte addressing and binary, decimal and (hexadecimal) floating-point calculations. The slowest System/360 model announced in 1964, the Model 30, could perform up to 34,500 instructions per second, with memory from 8 to 64 KB.[2] High performance models came later. The 1967 System 360 Model 91 could do up to 16.6 million instructions per second.[3] The larger 360 models could have up to 8 MB of internal main memory,[4] though main memory that big was unusual—a more typical large installation might have as little as 256 KB of main storage, but 512 KB, 768 KB or 1024 KB was more common. Up to 8 megabytes of slower (8 microsecond) Large Capacity Storage (LCS) was also available. System/360 was extremely successful in the market, allowing customers to purchase a smaller system with the knowledge they would always be able to migrate upward if their needs grew, without reprogramming of application software or replacing peripheral devices. Many consider the design one of the most successful computers in history, influencing computer design for years to come. The chief architect of System/360 was Gene Amdahl, and the project was managed by Fred Brooks, responsible to Chairman Thomas J. Watson Jr.[4] The commercial release was piloted by another of Watson's lieutenants, John R. Opel, who managed the launch of IBM’s System 360 mainframe family in 1964.[5] Application level compatibility (with some restrictions) for System/360 software is maintained to present day with the System z servers. http://en.wikipedia.org/wiki/IBM_System/360		IBM announced the System/360, a family of six mutually compatible computers and 40 peripherals that could work together. The initial investment of $5 billion was quickly returned as orders for the system climbed to 1,000 per month within two years. At the time IBM released the System/360, the company was making a transition from discrete transistors to integrated circuits, and its major source of revenue moved from punched-card equipment to electronic computer systems.