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| Developer | IBM |
|---|---|
| Release date | April 22, 1965 |
| Successor | Model 195 |
The IBM System/360 Model 75 is a discontinued high end/high performance [1] system that was introduced on April 22, 1965. [2] Although it played many roles in IBM's System/360 lineup, [3] it accounted for a small fraction of a percent of the 360 systems sold. [4] Five Model 75 computers housed at NASA's Real Time Computer Complex were used during the Apollo program. [5]
Three models, the H75, I75, and J75, were respectively configured with one, two, or four IBM 2365 Model 3 Processor Storage units, each of which provided 262,144 (256K) bytes of core memory, so that the H75 had 262,144 (256K) bytes of core, the I75 had 524,288 (512K), and the J75 1,048,576 (1 MB).
The high performance of the Model 75 was attributed [1] to half a dozen advanced features, including Parallel arithmetic, Overlapped memory fetch, and Parallel addition for address calculation.
Furthermore, independent storage sections provided two-way (H75) or four-way (I75, J75) interleaving of memory access. Even with only two-way interleaving, "an effective sequential access rate of 400 nanoseconds per double word (eight bytes) is possible".
The Model 75 implements the complete System/360 "universal instruction set" architecture, including floating-point, decimal, and character operations as standard features.
In processor design, microcode serves as an intermediary layer situated between the central processing unit (CPU) hardware and the programmer-visible instruction set architecture of a computer, also known as its machine code. It consists of a set of hardware-level instructions that implement the higher-level machine code instructions or control internal finite-state machine sequencing in many digital processing components. While microcode is utilized in general-purpose CPUs in contemporary desktops, it also functions as a fallback path for scenarios that the faster hardwired control unit is unable to manage.
The IBM System/360 (S/360) is a family of mainframe computer systems that was announced by IBM on April 7, 1964, and delivered between 1965 and 1978. It was the first family of computers designed to cover both commercial and scientific applications and a complete range of applications from small to large. The design distinguished between architecture and implementation, allowing IBM to release a suite of compatible designs at different prices. All but the only partially compatible Model 44 and the most expensive systems use microcode to implement the instruction set, featuring 8-bit byte addressing and fixed point binary, fixed point decimal and hexadecimal floating-point calculations.
The IBM System/370 (S/370) is a range of IBM mainframe computers announced as the successors to the System/360 family on June 30, 1970. The series mostly maintains backward compatibility with the S/360, allowing an easy migration path for customers; this, plus improved performance, were the dominant themes of the product announcement.
Magnetic-core memory is a form of random-access computer memory. It predominated for roughly 20 years between 1955 and 1975, and is often just called core memory, or, informally, core.
The IBM 7030, also known as Stretch, was IBM's first transistorized supercomputer. It was the fastest computer in the world from 1961 until the first CDC 6600 became operational in 1964.
CP-67 is a hypervisor, or Virtual Machine Monitor, from IBM for its System/360 Model 67 computer.
In computing, a memory address is a reference to a specific memory location used at various levels by software and hardware. Memory addresses are fixed-length sequences of digits conventionally displayed and manipulated as unsigned integers. Such numerical semantic bases itself upon features of CPU, as well upon use of the memory like an array endorsed by various programming languages.
In computing, channel I/O is a high-performance input/output (I/O) architecture that is implemented in various forms on a number of computer architectures, especially on mainframe computers. In the past, channels were generally implemented with custom devices, variously named channel, I/O processor, I/O controller, I/O synchronizer, or DMA controller.
The IBM System/360 Model 67 (S/360-67) was an important IBM mainframe model in the late 1960s. Unlike the rest of the S/360 series, it included features to facilitate time-sharing applications, notably a Dynamic Address Translation unit, the "DAT box", to support virtual memory, 32-bit addressing and the 2846 Channel Controller to allow sharing channels between processors. The S/360-67 was otherwise compatible with the rest of the S/360 series.
The RCA Spectra 70 is a line of electronic data processing (EDP) equipment that was manufactured by the Radio Corporation of America’s computer division beginning in April 1965. The Spectra 70 line included several CPU models, various configurations of core memory, mass-storage devices, terminal equipment, and a variety of specialized interface equipment.
This timeline of binary prefixes lists events in the history of the evolution, development, and use of units of measure which are germane to the definition of the binary prefixes by the International Electrotechnical Commission (IEC) in 1998, used primarily with units of information such as the bit and the byte.
The IBM 2365 Processor Storage is a magnetic-core memory storage unit that is a component of the IBM System/360 models 65, 67, 75 and 85 computers, which were released between 1965 and 1968.
The IBM 2361 Large Capacity Storage (LCS) is an optional component of the IBM System/360 models 50, 65 (when not being used as a multiprocessor), and 75 computers. Storage is implemented using magnetic cores; the cycle time is 8 microseconds and the access time is 3.6 microseconds. This component is also called IBM 2361 Core Storage or IBM 2361 Large Core Storage. It provides additional main storage with a slower access time than the standard storage of the machine—for example 8 microseconds compared to 750 nanoseconds for main storage on the Model 65.
The IBM System/360 architecture is the model independent architecture for the entire S/360 line of mainframe computers, including but not limited to the instruction set architecture. The elements of the architecture are documented in the IBM System/360 Principles of Operation and the IBM System/360 I/O Interface Channel to Control Unit Original Equipment Manufacturers' Information manuals.
In operating systems, memory management is the function responsible for managing the computer's primary memory.
The IBM System/360 Model 50 is a member of the IBM System/360 family of computers. The Model 50 was announced in April 1964 with the other initial models of the family, and first shipped in August 1965 to the Bank of America.
The IBM System/360 Model 65 is a member of the IBM System/360 family of computers. It was announced April 1965, and replaced two models, the Model 60 and Model 62, announced one year prior but never shipped. It was discontinued in March 1974.
The IBM System/360 Model 25 is a low-end member of the IBM System/360 family. It was announced on January 3, 1968, 3 years before the IBM System/360 Model 22, as a "bridge between its old and new computing systems".
The IBM System/360 Model 85 is a high-end member of the System/360 family of computers, with many advanced features, and was announced in January 1968 and first shipped in December 1969. IBM built only about 30 360/85 systems because of "a recession in progress".
The IBM 303X is a discontinued line of mainframe computers, the first model of which, the IBM 3033 Processor, nicknamed "The Big One", was introduced March 25, 1977.
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