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86-596: The System/360 family introduced IBM's Solid Logic Technology (SLT), which packed more transistors onto a circuit card, allowing more powerful but smaller computers. 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 . High-performance models came later. The 1967 IBM System/360 Model 91 could execute up to 16.6 million instructions per second . The larger 360 models could have up to 8  MB of main memory , though that much memory

172-623: A heart attack . After recovering, he was appointed by President Jimmy Carter to be chairman of the General Advisory Committee (GAC) on Arms Control and Disarmament, in support of the Arms Control and Disarmament Agency which had been previously set up by President John F. Kennedy . Watson advised President Carter against use of the experimental MX missile . After leaving the GAC, he was appointed by President Carter to be

258-498: A 0.5 inches (13 mm) square substrate with silk-screened resistors and printed connections. The whole is encapsulated to form a 0.5 inches (13 mm) square module. Up to 36 modules are mounted on each card, though a few card types had just discrete components and no modules. Cards plug into boards which are connected to form gates which form frames. SLT voltage levels, logic low to logic high, varied by circuit speed: The same basic packaging technology (both device and module)

344-775: A 2501 card reader operating at 600 cards per minute would be in 1-byte mode, while a 1403-N1 printer would be in burst mode. Also, the byte-multiplexer channels on larger models have an optional selector subchannel section that would accommodate tape drives. The byte-multiplexor's channel address was typically "0" and the selector subchannel addresses were from "C0" to "FF." Thus, tape drives on System/360 were commonly addressed at 0C0–0C7. Other common byte-multiplexer addresses are: 00A: 2501 Card Reader, 00C/00D: 2540 Reader/Punch, 00E/00F: 1403-N1 Printers, 010–013: 3211 Printers, 020–0BF: 2701/2703 Telecommunications Units. These addresses are still commonly used in z/VM virtual machines. System/360 models 40 and 50 have an integrated 1052-7 console that

430-651: A channel is to connect the devices in a chain, like this: Mainframe—Control Unit X—Control Unit Y—Control Unit Z. Each control unit is assigned a "capture range" of addresses that it services. For example, control unit X might capture addresses 40–4F, control unit Y: C0–DF, and control unit Z: 80–9F. Capture ranges had to be a multiple of 8, 16, 32, 64, or 128 devices and be aligned on appropriate boundaries. Each control unit in turn has one or more devices attached to it. For example, you could have control unit Y with 6 disks, that would be addressed as C0-C5. There are three general types of bus-and-tag cables produced by IBM. The first

516-415: A child he had a "strange defect in his vision" that made written words appear to fall off the page when he tried to read them. As a result, Watson struggled in school, and he acknowledged that Brown University reluctantly admitted him as a favor to his father. He graduated with a business degree in 1937. After graduating, Watson became a salesman for IBM but had little interest in the job. The turning point

602-534: A civilian. Watson was inducted into the Junior Achievement U.S. Business Hall of Fame in 1976. He was awarded the Vermilye Medal in 1967. In 1987 Fortune magazine hailed Watson on its cover as "the greatest capitalist in history." In 1998 he was included on TIME Magazine's 100 most influential people of the 20th century . Watson left IBM in 1971 on his doctor's advice after having

688-414: A customer could purchase a machine that solved a particular requirement, knowing they could change the models as their needs changed, without losing support for the programs they were already running. For instance, in the case of a firm that purchased an accounting system and was now looking to expand their computer support into engineering, this meant they could develop and test their engineering program on

774-776: A dozen computers in the entire world at the time. Even the supporters of the new technology underestimated the potential. Cuthbert Hurd , brought in from the Atomic Energy Commission 's Oak Ridge National Laboratory to determine if there was a market, predicted "... he could find customers for as many as thirty machines." Even so, until the late 1950s the custom-built US Air Force SAGE computerized tracking system accounted for more than half of IBM's computer sales. The company made little profit on these sales but, as Tom Jr. said "It enabled us to build highly automated factories ahead of anybody else, and to train thousands of new workers in electronics." Tom Jr.'s decision

860-486: A family of more powerful instructions such as the MVCL "Move-Characters-Long" instruction, which supports moving up to 16 MB as a single block.) An operand is two bytes long, typically representing an address as a 4-bit nibble denoting a base register and a 12-bit displacement relative to the contents of that register, in the range 000–FFF (shown here as hexadecimal numbers). The address corresponding to that operand

946-524: A reported cost of $ 20 million. Although embarrassing in terms of the rumors that drifted to the outside world, it would not however be the last IBM computer series to be terminated and the cost was small in IBM's terms; and the experience gained was invaluable. The three computer families that eventually emerged from 1958 onwards comprised the IBM 7070 and IBM 7090 for large government business and large businesses,

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1032-458: A smaller maximum memory configuration, and slower I/O channels, which limited it to slower and lower-capacity disk and tape devices than on the 30. The Model 44 (1966) was a specialized model, designed for scientific computing and for real-time computing and process control, featuring some additional instructions, and with all storage-to-storage instructions and five other complex instructions eliminated. A succession of high-end machines included

1118-896: A standard feature. If the Commercial Instruction Set option was installed, packed decimal arithmetic could be performed as memory-to-memory with some memory-to-register operations. The Scientific Instruction Set feature, if installed, provided access to four floating-point registers that could be programmed for either 32-bit or 64-bit floating-point operations. The Models 85 and 195 could also operate on 128-bit extended-precision floating-point numbers stored in pairs of floating-point registers, and software provided emulation in other models. The System/360 used an 8-bit byte, 32-bit word, 64-bit double-word, and 4-bit nibble . Machine instructions had operators with operands, which could contain register numbers or memory addresses. This complex combination of instruction options resulted in

1204-424: A superb sales organization but lacked expert management organization in almost everything else". His goal was to redirect IBM to absorb the shocks of change, including change from its own innovation. He introduced the terminology "line and staff". In his words: "By the mid-'50s just about every big corporation had adopted the so-called staff-and-line structure. It was modeled on military organizations going back to

1290-415: A variety of instruction lengths and formats. Memory addressing was accomplished using a base-plus-displacement scheme, with registers 1 through F (15). A displacement was encoded in 12 bits, thus allowing a 4096-byte displacement (0–4095), as the offset from the address put in a base register. Register 0 could not be used as a base register nor as an index register (nor as a branch address register), as "0"

1376-450: Is now more commonly referred to as an MMU . An experimental one-off unit was built based on a model 40. Before the 67, IBM had announced models 64 and 66, DAT versions of the 60 and 62, but they were almost immediately replaced with the 67 at the same time that the 60 and 62 were replaced with the 65. DAT hardware would reappear in the S/370 series in 1972, though it was initially absent from

1462-418: Is the contents of the specified general-purpose register plus the displacement. For example, an MVC instruction that moves 256 bytes (with length code 255 in hexadecimal as FF ) from base register 7, plus displacement 000 , to base register 8, plus displacement 001 , would be coded as the 6-byte instruction " D2FF 8001 7000 " (operator/length/address1/address2). The System/360 was designed to separate

1548-442: Is the standard gray bus-and-tag cable, followed by the blue bus-and-tag cable, and finally the tan bus-and-tag cable. Generally, newer cable revisions are capable of higher speeds or longer distances, and some peripherals specified minimum cable revisions both upstream and downstream. Solid Logic Technology Solid Logic Technology ( SLT ) was IBM 's method for hybrid packaging of electronic circuitry introduced in 1964 with

1634-400: Is usually addressed as 01F, however, this was not connected to the byte-multiplexer channel, but rather, had a direct internal connection to the mainframe. The model 30 attached a different model of 1052 through a 1051 control unit. The models 60 through 75 also use the 1052–7. Selector channels enabled I/O to high speed devices. These storage devices were attached to a control unit and then to

1720-588: The 11th national president of the Boy Scouts of America (1964–68), and the 16th United States Ambassador to the Soviet Union (1979–81). He received many honors during his lifetime, including being awarded the Presidential Medal of Freedom by Lyndon B. Johnson in 1964. Fortune called him "the greatest capitalist in history" and Time listed him as one of "100 most influential people of

1806-469: The 7000 series machines, never shipped and were replaced with the 65 and 75 , which were first delivered in November 1965, and January 1966, respectively. Later additions to the low-end included models 20 (1966, mentioned above), 22 (1971), and 25 (1968). The Model 20 had several sub-models; sub-model 5 was at the higher end of the model. The Model 22 was a recycled Model 30 with minor limitations:

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1892-528: The ALSIB - Northwest Staging Route to send military aircraft from the United States to the Soviet Union. Watson returned to IBM at the beginning of 1946. He was promoted to be a vice president just six months later and was promoted to the board just four months after that. He became Executive Vice-president in 1949. Watson became president of IBM in 1952 and was named as the company's CEO shortly before

1978-494: The IBM 1620 for smaller customers in the scientific community, and the IBM 1401 for commercial use by smaller organizations. Despite the fact that many observers believed that Tom Jr was frittering away the resources his father had built up, these new ranges were remarkably successful, doubling IBM's sales once more over the six years from 1958 ($ 1.17 billion) to 1964 ($ 2.31 billion), maintaining IBM's dramatic growth rate virtually undiminished at approaching 30% compound. The effect

2064-412: The IBM 9020 , a special cluster of modified System/360s for air traffic control, from 1970 until the 1990s. (Some 9020 software is apparently still used via emulation on newer hardware.) The System/360 introduced a number of industry standards to the marketplace, such as: The System/360 series computer architecture specification makes no assumptions on the implementation itself, but rather describes

2150-769: The IBM Z series. Computers that were mostly identical or compatible in terms of the machine code or architecture of the System/360 included Amdahl 's 470 family (and its successors), Hitachi mainframes, the UNIVAC 9000 series , Fujitsu as the Facom, the RCA Spectra 70 series, and the English Electric System 4 . The System 4 machines were built under license to RCA. RCA sold the Spectra series to what

2236-561: The Model 67 (1966, mentioned below, briefly anticipated as the 64 and 66), 85 (1969), 91 (1967, anticipated as the 92), 95 (1968), and 195 (1971). The 85 design was intermediate between the System/360 line and the follow-on System/370 and was the basis for the 370/165. There was a System/370 version of the 195, but it did not include Dynamic Address Translation. The implementations differed substantially, using different native data path widths, presence or absence of microcode, yet were extremely compatible. Except where specifically documented,

2322-575: The New Englander Motor Hotel in Greenwich, Connecticut , SPREAD developed a new concept for the next generation of IBM machines. At the time, new technologies were coming into the market including the introduction of replacement of individual transistors with small-scale integrated circuits and the move to an 8-bit byte from the former 6-bit oriented words. These were going to lead to a new generation of machines, today known as

2408-581: The Silver Buffalo Award from the Boy Scouts of America in 1955 for his service to youth. He was the national president of the BSA from 1964 to 1968. His father had also served on the national executive board and was International Commissioner in the 1940s. Lyndon B. Johnson in September 1964 awarded Watson the Presidential Medal of Freedom , the highest award a U.S. president can bestow on

2494-608: The Standard Modular System . It helped propel the IBM System/360 mainframe family to overwhelming success during the 1960s. SLT research produced ball chip assembly, wafer bumping , trimmed thick-film resistors, printed discrete functions, chip capacitors and one of the first volume uses of hybrid thick-film technology . SLT replaced the earlier Standard Modular System , although some later SMS cards held SLT modules. SLT had several updates during its life,

2580-834: The Watson Institute for International Studies at Brown University and the Thomas J. Watson Fellowship (which supports students to study a topic of personal interest for a year) and other charitable gifts. Watson contributed to the Watson Pavilion at Greenwich Hospital in Connecticut , which named the Olive and Thomas J. Watson Jr. Pavilion (a wing) after him and his wife. He was also the principal benefactor of Owls Head Transportation Museum in Owls Head, Maine . He

2666-402: The system state from the problem state . This provided a basic level of security and recoverability from programming errors. Problem (user) programs could not modify data or program storage associated with the system state. Addressing, data, or operation exception errors made the machine enter the system state through a controlled routine so the operating system could try to correct or terminate

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2752-434: The 20th century". Thomas Watson Jr. was born on January 14, 1914, just before his father, Thomas J. Watson , was dismissed from his job at cash register company NCR – an act which subsequently drove Watson Sr., to the foundation of the largest and most profitable digital computer manufacturer in the world, IBM Corporation . Two sisters followed Thomas Jr., Jane and Helen, before a final child, Arthur Kittredge Watson ,

2838-462: The 65 had a dual-processor version (M65MP) with extensions for inter-CPU signalling; the 85 introduced cache memory. Models 44, 75, 91, 95, and 195 were implemented with hardwired logic, rather than microcoded as all other models. The Model 67 , announced in August 1965, was the first production IBM system to offer dynamic address translation (virtual memory) hardware to support time-sharing . "DAT"

2924-440: The 7040 was incompatible with the 1401 and they might as well have been from different companies. Customers were frustrated that major investments, often entirely new machines and programs, were required when seemingly small performance improvements were needed. In 1961, IBM assembled a task force to chart their developments for the 1960s, known as SPREAD, for Systems Programming, Research, Engineering and Development. In meetings at

3010-495: The Consent Decree which was offered by the government after its latest anti-trust investigation. Tom Jr. saw that the Consent Decree, which sought to strip IBM of half its card-making capacity, was largely irrelevant since the future was in computers rather than cards. There was another condition: IBM had to sell machines outright as well as lease them. This had repercussions in the late 1960s when leasing companies recognized

3096-479: The IBM System/360 series of computers. It was also used in the 1130, announced in 1965. IBM chose to design custom hybrid circuits using discrete, flip chip -mounted, glass -encapsulated transistors and diodes , with silk-screened resistors on a ceramic substrate, forming an SLT module. The circuits were either encapsulated in plastic or covered with a metal lid. Several of these SLT modules (20 in

3182-452: The Model 20, which was not a standard 360) has a byte-multiplexer channel and 1 or more selector channels, though the model 25 has just one channel, which can be either a byte-multiplexor or selector channel. The smaller models (up to the model 50) have integrated channels, while for the larger models (model 65 and above) the channels are large separate units in separate cabinets: the IBM 2870 is

3268-596: The Models 20, 44 and 67) was replaced with the compatible System/370 range in 1970 and Model 20 users were targeted to move to the IBM System/3 . (The idea of a major breakthrough with FS technology was dropped in the mid-1970s for cost-effectiveness and continuity reasons.) Later compatible IBM systems include the 4300 family , the 308x family , the 3090 , the ES/9000 and 9672 families ( System/390 family), and

3354-769: The Prussian army in Napoleonic times." His organization "... provided IBM executives with the clearest possible goals. Each operating man was judged strictly on his unit's results, and each staff man on his effort toward making IBM the world leader in his specialty." The final element of formal organizational change was the isolation of headquarters staff in Armonk , New York . This was said by him to be in order to be near his family in Connecticut. His first book in 1963 discussed his management philosophy. Watson received

3440-459: The S/360 era. There were initially two types of channels; byte-multiplexer channels (known at the time simply as "multiplexor channels"), for connecting "slow speed" devices such as card readers and punches, line printers , and communications controllers, and selector channels for connecting high speed devices, such as disk drives , tape drives , data cells and drums . Every System/360 (except for

3526-534: The Soviet Union, recreating in 1987 the ALSIB route from World War II. Watson married Olive Cawley (1918–2004) in 1941. They had six children. He had homes in Greenwich , Connecticut ; North Haven , Maine ; Stowe , Vermont ; Vail , Colorado ; New York City ; and Antigua . He died in Greenwich on December 31, 1993, of complications following a stroke . He was 79. Watson was the principal benefactor of

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3612-653: The US Ambassador to the Soviet Union , serving from October 29, 1979, to January 15, 1981. Following his return home after Carter's defeat by Ronald Reagan in the 1980 United States presidential election , Watson gave the commencement speech at Harvard University in 1981 in which he warned against further escalation against the USSR. He was also a member of the Bohemian Club . He was an avid sailor and pilot. He named 7 successive sailboats after Palawan ,

3698-528: The accounting system outright with a system with the performance to run both tasks. The idea that a single design could address all the myriad ways that the machines could be used gave rise to the name, "360" is a reference to 360 degrees in a circle, and circles of machines and components featured prominently in IBM's advertising. IBM initially announced a series of six computers and forty common peripherals. IBM eventually delivered fourteen models, including rare one-off models for NASA . The least expensive model

3784-555: The byte-multiplexor channel with up to four selector sub-channels, and the IBM 2860 is up to three selector channels. The byte-multiplexer channel is able to handle I/O to/from several devices simultaneously at the device's highest rated speeds, hence the name, as it multiplexed I/O from those devices onto a single data path to main memory. Devices connected to a byte-multiplexer channel are configured to operate in 1-byte, 2-byte, 4-byte, or "burst" mode. The larger "blocks" of data are used to handle progressively faster devices. For example,

3870-434: The channel. The control unit let clusters of devices be attached to the channels. On higher speed models, multiple selector channels, which could operate simultaneously or in parallel, improved overall performance. Control units are connected to the channels with "bus and tag" cable pairs. The bus cables carried the address and data information and the tag cables identified what data was on the bus. The general configuration of

3956-466: The concept steadily gained support, and six months after being formed, the company decided to implement the SPREAD concept. A new team was organized under the direction of Bob Evans , who personally persuaded CEO Thomas J. Watson Jr. to develop the new system. Gene Amdahl was the chief architect of the computers themselves, while Fred Brooks was the project lead for the software and Erich Bloch led

4042-527: The costs and delay of creating a 5100-specific version of APL. Special radiation-hardened and otherwise somewhat modified System/360s, in the form of the System/4 Pi avionics computer, are used in several fighter and bomber jet aircraft. In the complete 32-bit AP-101 version, 4 Pi machines were used as the replicated computing nodes of the fault-tolerant Space Shuttle computer system (in five nodes). The U.S. Federal Aviation Administration operated

4128-507: The customer to write such a package or buy another machine. This meant that a single lineup could have machines tailored to match the price and performance niches that formerly demanded entirely separate computer systems. This flexibility greatly lowered barriers to entry. With most other vendors customers had to choose between machines they might outgrow or machines that were potentially too powerful and thus too costly. In practice, this meant that many companies simply did not buy computers. Now,

4214-612: The death of his father, Watson Sr., in 1956. Up to this time IBM was dedicated to electromechanical punched card systems for its commercial products. Watson Sr. had repeatedly rejected electronic computers as overpriced and unreliable, except for one-of-a-kind projects such as the IBM SSEC . Tom Jr. took the company in a new direction, hiring electrical engineers by the hundreds and putting them to work designing mainframe computers . Many of IBM's technical experts also did not think computer products were practical since there were only about

4300-407: The development of IBM's hybrid integrated circuit designs, Solid Logic Technology . Producing a single machine with support for all of these features would border on impossible. Instead, the SPREAD concept was based on the separation of the defined feature set from its internal operation, with a family of machines with different performance and different internal designs. Specifically, depending on

4386-402: The early 1960s, IBM was struggling with the load of supporting and upgrading five separate lines of computers. These were aimed at different market segments and were entirely different from each other. A customer who purchased a machine to handle accounting, such as the IBM 1401 , that was now looking for a machine for engineering calculations, such as the IBM 7040 , had no reason to select IBM –

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4472-557: The end of his service, Watson worked for Major General Follett Bradley , who suggested that he should try to follow his father at IBM. Watson regularly flew Bradley, the director of lend-lease programs to the Soviet Union , to Moscow during the war. On these trips, he learned Russian, which would later serve him well as the American Ambassador to the Soviet Union. Watson and Bradley were instrumental in establishing

4558-601: The end, paid off. Perhaps Watson's most enduring contribution to IBM was its organizational structure, since new products, no matter how successful, carry a company for at most a few years. In 1956, in a move that became a bi-annual event, he reorganized IBM on divisional lines, to give a decentralized organization, with five major divisions in the US. The new structure comprised: Smaller units were Electric Typewriter, IBM World Trade, Service Bureau Corporation , Supplies Division; and Time Division (sold off in 1958). Watson said "We had

4644-422: The equivalent figure for Japan was 5.1%, though its high technology companies exceeded even the IBM level, with the 1983 spending for Canon being 14.6% and that for NEC being 13.0%. This training program was to take him, over the next five years, through many of IBM's operating groups. Tom Jr. believed his most important influence was Albert Lynn Williams , a CPA , who became president of IBM in 1961. Although

4730-443: The financing loophole that it created. Behind this decision was another: spending more on research and development. IBM was only spending 3% on research and development at that time when other high technology companies were spending between 6% and 9%. Tom Jr. learned the lesson, and thereafter – at least until the 1990s (when, even then, Louis V. Gerstner Jr. only dropped it to 6%) – IBM consistently spent 9%. By comparison,

4816-504: The image on the right) were then mounted on a small multi-layer printed circuit board to make an SLT card. Each SLT card had a socket on one edge that plugged into pins on the computer's backplane (the exact reverse of how most other companies' modules were mounted). IBM considered monolithic integrated circuit technology too immature at the time. SLT was a revolutionary technology for 1964, with much higher circuit densities and improved reliability over earlier packaging techniques such as

4902-425: The initiative, and as such much of the credit for the birth of the information revolution, must go to Tom Jr., considerable courage was also displayed by his then aging father who, despite his long commitment to internal funding, backed his son to the hilt; reportedly with the words "It is harder to keep a business great than it is to build it." In 1968, Tom Jr. fired computer scientist Lynn Conway because he feared

4988-449: The instruction was performed). This specific behavior permitted initial execution of an interrupt routines, since base registers would not necessarily be set to 0 during the first few instruction cycles of an interrupt routine. It isn't needed for IPL ("Initial Program Load" or boot), as one can always clear a register without the need to save it. With the exception of the Model 67, all addresses were real memory addresses. Virtual memory

5074-481: The interfaces and expected behavior of an implementation. The architecture describes mandatory interfaces that must be available on all implementations, and optional interfaces. Some aspects of this architecture are: Some of the optional features are: All models of System/360, except for the Model 20 and Model 44, implemented that specification. Binary arithmetic and logical operations are performed as register-to-register and as memory-to-register/register-to-memory as

5160-610: The last being the Monolithic System Technology ( MST ) which replaced the single transistors of SLT with small-scale integrated circuits that held four or five transistors. MST was used in the System/370 , which began to replace the System/360 in 1970. SLT used silicon planar glass-encapsulated transistors and diodes. SLT uses dual diode chips and individual transistor chips each approximately 0.025 inches (0.64 mm) square. The chips are mounted on

5246-728: The last in 1991. Watson sailed one of his Palawans farther up the northern coast of Greenland than any non-military ship had done previously, receiving the New York Yacht Club 's highest award and the Cruising Club of America 's Blue Water Medal . He traveled the route of Captain Cook in exploring the Pacific. He flew helicopters, jets, and stunt planes, and was the first private citizen to receive permission from Soviet General Secretary Mikhail Gorbachev to fly across

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5332-435: The machine they already used. If they ever needed more performance, they could purchase a machine with floating-point hardware, knowing that nothing else would change, it would simply get faster. Even the same peripherals could be used, allowing, for instance, data from the engineering system to be written to tape and then printed using a high-speed line printer already connected to their accounting system. Or they might replace

5418-405: The machine, some instructions might not be directly supported in hardware, and would instead be completed using small programs, in an internal machine-specific code, stored in read only memory , or what today is known as microcode . So a model intended for use with accounting might choose to implement the decimal math directly in hardware, and leave the floating-point instructions to be handled by

5504-411: The models were architecturally compatible. The 91 , for example, was designed for scientific computing and provided out-of-order instruction execution (and could yield "imprecise interrupts" if a program trap occurred while several instructions were being read), but lacked the decimal instruction set used in commercial applications. New features could be added without violating architectural definitions:

5590-437: The new machine. Customers initially had to halt the computer and load the emulation program. IBM later added features and modified emulator programs to allow emulation of the 1401, 1440, 1460, 1410 and 7010 under the control of an operating system. The Model 85 and later System/370 maintained the precedent, retaining emulation options and allowing emulators to run under OS control alongside native programs. System/360 (excepting

5676-412: The news of her transition would affect the company's reputation. Prior to his time, IBM had primarily emphasized the sales organization, with a reasonable range of products. Tom Watson Jr., however, promoted a research and development structure. The first result of this was the IBM 7030 Stretch program to develop a transistorized "supercomputer"; it failed to meet its price and performance goals, at

5762-584: The program in error. Similarly, it could recover certain processor hardware errors through the machine check routines. Peripherals interfaced to the system via channels . A channel is a specialized processor with the instruction set optimized for transferring data between a peripheral and main memory. In modern terms, this could be compared to direct memory access (DMA). The S/360 connects channels to control units with bus and tag cables; IBM eventually replaced these with Enterprise Systems Connection (ESCON) and Fibre Connection (FICON) channels, but well after

5848-440: The series. Like its close relative, the 65, the 67 also offered dual CPUs. IBM stopped marketing all System/360 models by the end of 1977. IBM's existing customers had a large investment in software that ran on second-generation machines . Several System/360 models had the option of emulating the customer's existing computer using special hardware and microcode , and an emulation program that enabled existing programs to run on

5934-435: The subprograms. This would make floating point on such a system run (much) more slowly, but, critically, it would run. Likewise, a company purchasing a system for engineering support would choose a model with floating-point hardware, and might use it from time to time to run their payroll. Using previous designs, the system that performed floating point would generally not have any support for decimal math all, and would require

6020-476: The third generation, from all of the existing vendors. Where SPREAD differed significantly from previous concepts was what features would be supported. Instead of machines aimed at different market niches, the new concept was effectively the union of all of these designs. A single instruction set architecture (ISA) included instructions for binary , floating-point , and decimal arithmetic, string processing, conversion between character sets (a major issue before

6106-495: The widespread use of ASCII ) and extensive support for file handling, among many other features. This would mean IBM would be introducing yet another line of machines, once again incompatible with their earlier machines. But the new systems would be able to run all of the programs that formerly required different machines. A concern was that there was a risk that their customers, facing the purchase of yet another new and incompatible platform, would simply choose some other vendor. Yet

6192-479: Was Gene Amdahl , and the project was managed by Fred Brooks , responsible to Chairman Thomas J. Watson Jr. 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. Application-level compatibility (with some restrictions) for System/360 software is maintained to the present day with the System z mainframe servers. By

6278-409: Was a record even better than that of his father. Despite the presence of his son, Thomas Sr. kept a firm grip on the reins until 1955. Tom Jr. described the position of his father as "He wanted to make me head of IBM, but he didn't like sharing the limelight." Tom Jr. took over effective control in a dramatic moment; though the formal handover took place a few months later. The occasion was signing

6364-406: Was also used for the devices that replaced SLT as IBM gradually transitioned to the use of monolithic integrated circuits: Thomas J. Watson Jr. Thomas John Watson Jr. (January 14, 1914 – December 31, 1993) was an American businessman, diplomat, Army Air Forces pilot, and philanthropist. The son of IBM Corporation founder Thomas J. Watson , he was the second IBM president (1952–71),

6450-629: Was born. Watson Jr. was raised in the Short Hills section of Millburn, New Jersey . Both sons were immersed in IBM from a very early age. He was taken on plant inspections – his first memory of such a visit (to the Dayton , Ohio factory) was at the age of five – and business tours to Europe and made appearances at annual gatherings for the company's elite sales representatives, the IBM Hundred Per Cent Club, even before he

6536-483: Was his service as a pilot in the Army Air Forces during World War II . His brother "Dick" (Arthur) Watson had dropped out of Yale . Watson became a lieutenant colonel, tasked with flying military commanders. Tom Jr. later admitted to journalists that the one career he would have liked to follow was an airline pilot. Piloting came easily to him and for the first time, he had confidence in his abilities. Toward

6622-426: Was justified; in the longer term, it redirected IBM to its later position dominating the computer market. Even in the short term it paid off; for revenues more than tripled in six years, from $ 214.9 million in 1950 to $ 734.3 million in 1956. This dramatic rate of growth almost matched the wartime years; a better than 30% compound growth rate that Tom Jr. maintained for much of the twenty years of his leadership of IBM. It

6708-549: Was not all negative: "I really enjoyed the ten years (working) with him". In his book he says; "I was so intimately entwined with my father. I had a compelling desire, maybe out of honor for the old gentleman, maybe out of sheer cussedness, to prove to the world that I could excel in the same way that he did." Watson attended the Hun School of Princeton in Princeton , New Jersey . He claimed in his autobiography that as

6794-620: Was not available in most IBM mainframes until the System/370 series. The Model 67 introduced a virtual memory architecture, which MTS , CP-67 , and TSS/360 used—but not IBM's mainline System/360 operating systems. The System/360 machine-code instructions are 2 bytes long (no memory operands), 4 bytes long (one operand), or 6 bytes long (two operands). Instructions are always situated on 2-byte boundaries. Operations like MVC (Move-Characters) (Hex: D2) can only move at most 256 bytes of information. Moving more than 256 bytes of data required multiple MVC operations. (The System/370 series introduced

6880-431: Was old enough to attend school. At home his father's discipline was erratic and often harsh. Around the time he was thirteen, Watson suffered from clinical depression . Talking to a reporter in 1974, Watson described his relationship with his father; "My father and I had terrible fights ... He seemed like a blanket that covered everything. I really wanted to beat him but also make him proud of me." But this relationship

6966-591: Was on the board of directors of the Bedford Stuyvesant Restoration Corporation and helped bring a factory employing over 300 people to the community that made cables, including ones for the US space program. After leaving IBM, Watson donated tens of millions of dollars to Columbia University from 1975 onward. These included the Thomas J. Watson Library of Business and Economics and several smaller building grants. Watson funded

7052-402: Was reserved to indicate an address in the first 4 KB of memory, that is, if register 0 was specified as described, the value 0x00000000 was implicitly input to the effective address calculation in place of whatever value might be contained within register 0 (or if specified as a branch address register, then no branch was taken, and the content of register 0 was ignored, but any side effect of

7138-559: Was that IBM had become independent of outside funding. In the early 1960s he oversaw the IBM System/360 project, which produced an entire line of computers that ran the same software and used the same peripherals . Since the 360 line was incompatible with IBM's previous products, it represented an enormous risk for the company. Despite delays in shipment, the products were well-received following their launch in 1964 and what Fortune magazine called "IBM's $ 5 Billion Gamble," in

7224-485: Was the Model 20 with as little as 4096 bytes of core memory , eight 16-bit registers instead of the sixteen 32-bit registers of other System/360 models, and an instruction set that was a subset of that used by the rest of the range. The initial announcement in 1964 included Models 30 , 40 , 50 , 60, 62, and 70. The first three were low- to middle-range systems aimed at the IBM 1400 series market. All three first shipped in mid-1965. The last three, intended to replace

7310-588: Was then UNIVAC , where they became the UNIVAC Series 70. UNIVAC also developed the UNIVAC Series 90 as successors to the 9000 series and Series 70. The Soviet Union produced a System/360 clone named the ES EVM . The IBM 5100 portable computer, introduced in 1975, offered an option to execute the System/360's APL.SV programming language through a hardware emulator. IBM used this approach to avoid

7396-615: Was unusual; a 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 for some models. The IBM 360 was extremely successful, allowing customers to purchase a smaller system knowing they could expand it, if their needs grew, without reprogramming application software or replacing peripheral devices. It influenced computer design for years to come; many consider it one of history's most successful computers. System/360's chief architect

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