The Cray-1 was a

supercomputer A supercomputer is a type of computer with a high level of performance as compared to a general-purpose computer. The performance of a supercomputer is commonly measured in floating-point operations per second (FLOPS) instead of million instruc ...

designed, manufactured and marketed by

Cray Research Cray Inc., a subsidiary of Hewlett Packard Enterprise, is an American supercomputer manufacturer headquartered in Seattle, Washington. It also manufactures systems for data storage and analytics. Several Cray supercomputer systems are listed i ...

. Announced in 1975, the first Cray-1 system was installed at

Los Alamos National Laboratory Los Alamos National Laboratory (often shortened as Los Alamos and LANL) is one of the sixteen research and development Laboratory, laboratories of the United States Department of Energy National Laboratories, United States Department of Energy ...

in 1976. Eventually, eighty Cray-1s were sold, making it one of the most successful supercomputers in history. It is perhaps best known for its unique shape, a relatively small C-shaped cabinet with a ring of benches around the outside covering the power supplies and the cooling system. The Cray-1 was the first supercomputer to successfully implement the

vector processor In computing, a vector processor or array processor is a central processing unit (CPU) that implements an instruction set where its instructions are designed to operate efficiently and effectively on large one-dimensional arrays of data called ...

design. These systems improve the performance of math operations by arranging memory and registers to quickly perform a single operation on a large set of data. Previous systems like the

CDC STAR-100 The CDC STAR-100 is a vector supercomputer that was designed, manufactured, and marketed by Control Data Corporation (CDC). It was one of the first machines to use a vector processor to improve performance on appropriate scientific applications. I ...

and ASC had implemented these concepts but did so in a way that seriously limited their performance. The Cray-1 addressed these problems and produced a machine that ran several times faster than any similar design. The Cray-1's architect was

Seymour Cray Seymour Roger Cray (September 28, 1925 – October 5, 1996)
– was an American

History

From 1968 to 1972, Seymour Cray of

Control Data Corporation Control Data Corporation (CDC) was a mainframe and supercomputer company that in the 1960s was one of the nine major U.S. computer companies, which group included IBM, the Burroughs Corporation, and the Digital Equipment Corporation (DEC), the N ...

(CDC) worked on the

CDC 8600 The CDC 8600 was the last of Seymour Cray's supercomputer designs while he worked for Control Data Corporation. As the natural successor to the CDC 6600 and CDC 7600, the 8600 was intended to be about 10 times as fast as the 7600, already the fast ...

, the successor to his earlier

CDC 6600 The CDC 6600 was the flagship of the 6000 series of mainframe computer systems manufactured by Control Data Corporation. Generally considered to be the first successful supercomputer, it outperformed the industry's prior recordholder, the I ...

and

CDC 7600 The CDC 7600 was designed by Seymour Cray to be the successor to the CDC 6600, extending Control Data Corporation, Control Data's dominance of the supercomputer field into the 1970s. The 7600 ran at 36.4 MHz (27.5 ns clock cycle) and had ...

designs. The 8600 was essentially made up of four 7600s in a box with an additional special mode that allowed them to operate lock-step in a

SIMD Single instruction, multiple data (SIMD) is a type of parallel computer, parallel processing in Flynn's taxonomy. SIMD describes computers with multiple processing elements that perform the same operation on multiple data points simultaneousl ...

fashion. Jim Thornton, formerly Cray's engineering partner on earlier designs, had started a more radical project known as the

. Unlike the 8600's brute-force approach to performance, the STAR took an entirely different route. The main processor of the STAR had lower performance than the 7600, but added hardware and instructions to speed up particularly common supercomputer tasks. By 1972, the 8600 had reached a dead end; the machine was so incredibly complex that it was impossible to get one working properly. Even a single faulty component would render the machine non-operational. Cray went to William Norris, Control Data's CEO, saying that a redesign from scratch was needed. At the time, the company was in serious financial trouble, and with the STAR in the pipeline as well, Norris could not invest the money. As a result, Cray left CDC and started

very close to the CDC lab. In the back yard of the land he purchased in Chippewa Falls, Cray and a group of former CDC employees started looking for ideas. At first, the concept of building another supercomputer seemed impossible, but after Cray Research's Chief Technology Officer travelled to

Wall Street Wall Street is a street in the Financial District, Manhattan, Financial District of Lower Manhattan in New York City. It runs eight city blocks between Broadway (Manhattan), Broadway in the west and South Street (Manhattan), South Str ...

and found a lineup of investors willing to back Cray, all that was needed was a design. For four years Cray Research designed its first computer. In 1975 the 80 MHz Cray-1 was announced. The excitement was so high that a bidding war for the first machine broke out between

Lawrence Livermore National Laboratory Lawrence Livermore National Laboratory (LLNL) is a Federally funded research and development centers, federally funded research and development center in Livermore, California, United States. Originally established in 1952, the laboratory now i ...

and

, the latter eventually winning and receiving serial number 001 in 1976 for a six-month trial. The

National Center for Atmospheric Research The US National Center for Atmospheric Research (NCAR ) is a US federally funded research and development center (FFRDC) managed by the nonprofit University Corporation for Atmospheric Research (UCAR) and funded by the National Science Foundat ...

(NCAR) was the first official customer of Cray Research in 1977, paying US$8.86 million ($7.9 million plus $1 million for the disks) for serial number 3. The NCAR machine was decommissioned in 1989. The company expected to sell perhaps a dozen of the machines, and set the selling price accordingly, but ultimately over 80 Cray-1s of all types were sold, priced from $5M to $8M. The machine made Seymour Cray a celebrity and his company a success, lasting until the supercomputer crash in the early 1990s. Based on a recommendation by William Perry's study, the NSA purchased a Cray-1 for theoretical research in

cryptanalysis Cryptanalysis (from the Greek ''kryptós'', "hidden", and ''analýein'', "to analyze") refers to the process of analyzing information systems in order to understand hidden aspects of the systems. Cryptanalysis is used to breach cryptographic se ...

. According to Budiansky, "Though standard histories of Cray Research would persist for decades in stating that the company's first customer was Los Alamos National Laboratory, in fact it was NSA..." The 160 MFLOPS Cray-1 was succeeded in 1982 by the 800 MFLOPS

Cray X-MP The Cray X-MP was a supercomputer designed, built and sold by Cray, Cray Research. It was announced in 1982 as the "cleaned up" successor to the 1975 Cray-1, and was the world's fastest computer from 1983 to 1985 with a quad-processor system perfo ...

, the first Cray multi-processing computer. In 1985, the very advanced

Cray-2 The Cray-2 is a supercomputer with four vector processors made by Cray Research starting in 1985. At 1.9 GFLOPS peak performance, it was the fastest machine in the world when it was released, replacing the Cray X-MP in that spot. It was, ...

, capable of 1.9 GFLOPS peak performance, succeeded the first two models but met a somewhat limited commercial success because of certain problems at producing sustained performance in real-world applications. A more conservatively designed evolutionary successor of the Cray-1 and X-MP models was therefore made by the name

Cray Y-MP The Cray Y-MP was a supercomputer sold by Cray, Cray Research from 1988, and the successor to the company's Cray X-MP, X-MP. The Y-MP retained software compatibility with the X-MP, but extended the address registers from 24 to 32 bits. High-densit ...

and launched in 1988. By comparison, the processor in a typical 2013 smart device, such as a

Google Google LLC (, ) is an American multinational corporation and technology company focusing on online advertising, search engine technology, cloud computing, computer software, quantum computing, e-commerce, consumer electronics, and artificial ...

Nexus 10 or HTC One, performs at roughly 1 GFLOPS, while the A13 processor in a 2019 iPhone 11 performs at 154.9 GFLOPS, a mark supercomputers succeeding the Cray-1 would not reach until 1994.

Background

Typical scientific workloads consist of reading in large data sets, transforming them in some way and then writing them back out again. Normally the transformations being applied are identical across all of the data points in the set. For instance, the program might add 5 to every number in a set of a million numbers. In simple computers the program would loop over all million numbers, adding five, thereby executing a million instructions saying a = add b, c. Internally the computer solves this instruction in several steps. First it reads the instruction from memory and decodes it, then it collects any additional information it needs, in this case the numbers b and c, and then finally runs the operation and stores the results. The end result is that the computer requires tens or hundreds of millions of cycles to carry out these operations.

Vector machines

In the STAR, new instructions essentially wrote the loops for the user. The user told the machine where in memory the list of numbers was stored, then fed in a single instruction a(1..1000000) = addv b(1..1000000), c(1..1000000). At first glance it appears the savings are limited; in this case the machine fetches and decodes only a single instruction instead of 1,000,000, thereby saving 1,000,000 fetches and decodes, perhaps one-fourth of the overall time. The real savings are not so obvious. Internally, the CPU of the computer is built up from a number of separate parts dedicated to a single task, for instance, adding a number, or fetching from memory. Normally, as the instruction flows through the machine, only one part is active at any given time. This means that each sequential step of the entire process must complete before a result can be saved. The addition of an

instruction pipeline In computer engineering, instruction pipelining is a technique for implementing instruction-level parallelism within a single processor. Pipelining attempts to keep every part of the processor busy with some instruction by dividing incoming Mac ...

changes this. In such machines the CPU will "look ahead" and begin fetching succeeding instructions while the current instruction is still being processed. In this

assembly line An assembly line, often called ''progressive assembly'', is a manufacturing process where the unfinished product moves in a direct line from workstation to workstation, with parts added in sequence until the final product is completed. By mechan ...

fashion any one instruction still requires as long to complete, but as soon as it finishes executing, the next instruction is right behind it, with most of the steps required for its execution already completed.

Vector processor In computing, a vector processor or array processor is a central processing unit (CPU) that implements an instruction set where its instructions are designed to operate efficiently and effectively on large one-dimensional arrays of data called ...

s use this technique with one additional trick. Because the data layout is in a known format — a set of numbers arranged sequentially in memory — the pipelines can be tuned to improve the performance of fetches. On the receipt of a vector instruction, special hardware sets up the memory access for the arrays and stuffs the data into the processor as fast as possible. CDC's approach in the STAR used what is today known as a ''memory-memory architecture''. This referred to the way the machine gathered data. It set up its pipeline to read from and write to memory directly. This allowed the STAR to use vectors of length not limited by the length of registers, making it highly flexible. Unfortunately, the pipeline had to be very long in order to allow it to have enough instructions in flight to make up for the slow memory. That meant the machine incurred a high cost when switching from processing vectors to performing operations on non-vector operands. Additionally, the low scalar performance of the machine meant that after the switch had taken place and the machine was running scalar instructions, the performance was quite poor. The result was rather disappointing real-world performance, something that could, perhaps, have been forecast by

Amdahl's law In computer architecture, Amdahl's law (or Amdahl's argument) is a formula that shows how much faster a task can be completed when more resources are added to the system. The law can be stated as: "the overall performance improvement gained by ...

Cray's approach

Cray studied the failure of the STAR and learned from it. He decided that in addition to fast vector processing, his design would also require excellent all-around scalar performance. That way when the machine switched modes, it would still provide superior performance. Additionally he noticed that the workloads could be dramatically improved in most cases through the use of registers. Just as earlier machines had ignored the fact that most operations were being applied to many data points, the STAR ignored the fact that those same data points would be repeatedly operated on. Whereas the STAR would read and process the same memory five times to apply five vector operations on a set of data, it would be much faster to read the data into the CPU's registers once, and then apply the five operations. However, there were limitations with this approach. Registers were significantly more expensive in terms of circuitry, so only a limited number could be provided. This implied that Cray's design would have less flexibility in terms of vector sizes. Instead of reading any sized vector several times as in the STAR, the Cray-1 would have to read only a portion of the vector at a time, but it could then run several operations on that data prior to writing the results back to memory. Given typical workloads, Cray felt that the small cost incurred by being required to break large sequential memory accesses into segments was a cost well worth paying. Since the typical vector operation would involve loading a small set of data into the vector registers and then running several operations on it, the vector system of the new design had its own separate pipeline. For instance, the multiplication and addition units were implemented as separate hardware, so the results of one could be internally pipelined into the next, the instruction decode having already been handled in the machine's main pipeline. Cray referred to this concept as ''chaining'', as it allowed programmers to "chain together" several instructions and extract higher performance.

Performance

In 1978, a team from the

Argonne National Laboratory Argonne National Laboratory is a Federally funded research and development centers, federally funded research and development center in Lemont, Illinois, Lemont, Illinois, United States. Founded in 1946, the laboratory is owned by the United Sta ...

tested a variety of typical workloads on a Cray-1 as part of a proposal to purchase one for their use, replacing their IBM 370/195. They also planned on testing on the

and Burroughs Scientific Computer, but such tests, if they were performed, were not published. The tests were run on the Cray-1 at the

(NCAR) in

Boulder, Colorado Boulder is a List of municipalities in Colorado#Home rule municipality, home rule city in Boulder County, Colorado, United States, and its county seat. With a population of 108,250 at the 2020 United States census, 2020 census, it is the most ...

. The only other Cray available at the time was the one at Los Alamos, but accessing this machine required

Q clearance Q clearance or Q access authorization is the U.S. Department of Energy (DOE) security clearance required to access Top Secret Restricted Data, Formerly Restricted Data, and National Security Information, as well as Secret Restricted Data. Restric ...

. The tests were reported in two ways. The first was a minimum conversion needed to get the program running without errors, but making no attempt to take advantage of the Cray's vectorization. The second included a moderate set of updates to the code, often unwinding loops so they could be vectorized. Generally, the minimal conversions ran roughly the same speed as the 370 to about 2 times its performance (mostly due to a larger exponent range on the Cray), but vectorization led to further increases between 2.5 and 10 times. In one example program, which performed an internal

fast Fourier transform A fast Fourier transform (FFT) is an algorithm that computes the discrete Fourier transform (DFT) of a sequence, or its inverse (IDFT). A Fourier transform converts a signal from its original domain (often time or space) to a representation in ...

, performance improved from the IBM's 47 milliseconds to 3.

Description

The new machine was the first Cray design to use

integrated circuit An integrated circuit (IC), also known as a microchip or simply chip, is a set of electronic circuits, consisting of various electronic components (such as transistors, resistors, and capacitors) and their interconnections. These components a ...

s (ICs). Although ICs had been available since the 1960s, it was only in the early 1970s that they reached the performance necessary for high-speed applications. The Cray-1 used only four different IC types, an ECL dual 5-4

NOR gate The NOR (NOT OR) gate is a digital logic gate that implements logical NOR - it behaves according to the truth table to the right. A HIGH output (1) results if both the inputs to the gate are LOW (0); if one or both input is HIGH (1), a LOW o ...

(one 5-input, and one 4-input, each with differential output), another slower MECL 10K 5-4 NOR gate used for address fanout, a 16×4-bit high speed (6 ns)

static RAM Static random-access memory (static RAM or SRAM) is a type of random-access memory (RAM) that uses latching circuitry (flip-flop) to store each bit. SRAM is volatile memory; data is lost when power is removed. The ''static'' qualifier differ ...

(SRAM) used for registers and a 1,024×1-bit 48 ns SRAM used for the main memory. These integrated circuits were supplied by

Fairchild Semiconductor Fairchild Semiconductor International, Inc. was an American semiconductor company based in San Jose, California. It was founded in 1957 as a division of Fairchild Camera and Instrument by the " traitorous eight" who defected from Shockley Semi ...

and

Motorola Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois. It was founded by brothers Paul and Joseph Galvin in 1928 and had been named Motorola since 1947. Many of Motorola's products had been ...

. In all, the Cray-1 contained about 200,000 gates. ICs were mounted on large five-layer

printed circuit board A printed circuit board (PCB), also called printed wiring board (PWB), is a Lamination, laminated sandwich structure of electrical conduction, conductive and Insulator (electricity), insulating layers, each with a pattern of traces, planes ...

s, with up to 144 ICs per board. Boards were then mounted back to back for cooling (see below) and placed in twenty-four racks containing 72 double-boards. The typical module (distinct processing unit) required one or two boards. In all the machine contained 1,662 modules in 113 varieties. Each cable between the modules was a

twisted pair Twisted pair cabling is a type of communications cable in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic compatibility. Compared to a single conductor or an untwisted balanced ...

, cut to a specific length in order to guarantee the signals arrived at precisely the right time and minimize electrical reflection. Each signal produced by the ECL circuitry was a differential pair, so the signals were balanced. This tended to make the demand on the power supply more constant and reduce switching noise. The load on the power supply was so evenly balanced that Cray boasted that the power supply was unregulated. To the power supply, the entire computer system looked like a simple resistor. The high-performance ECL circuitry generated considerable heat, and Cray's designers spent as much effort on the design of the refrigeration system as they did on the rest of the mechanical design. In this case, each circuit board was paired with a second, placed back to back with a sheet of copper between them. The copper sheet conducted heat to the edges of the cage, where liquid

Freon Freon ( ) is a registered trademark of the Chemours Company and generic descriptor for a number of halocarbon products. They are stable, nonflammable, low toxicity gases or liquids which have generally been used as refrigerants and as aerosol p ...

running in stainless steel pipes drew it away to the cooling unit below the machine. The first Cray-1 was delayed six months due to problems in the cooling system; lubricant that is normally mixed with the Freon to keep the compressor running would leak through the seals and eventually coat the boards with oil until they shorted out. New welding techniques had to be used to properly seal the tubing. In order to bring maximum speed out of the machine, the entire chassis was bent into a large C-shape. Speed-dependent portions of the system were placed on the "inside edge" of the chassis, where the wire-lengths were shorter. This allowed the cycle time to be decreased to 12.5 ns (80 MHz), not as fast as the 8 ns 8600 he had given up on, but fast enough to beat

and the STAR. NCAR estimated that the overall throughput on the system was 4.5 times that of the CDC 7600. The Cray-1 was built as a

64-bit In computer architecture, 64-bit integers, memory addresses, or other data units are those that are 64 bits wide. Also, 64-bit central processing units (CPU) and arithmetic logic units (ALU) are those that are based on processor registers, a ...

system, a departure from the 7600/6600, which were 60-bit machines (a change was also planned for the 8600). Addressing was 24-bit, with a maximum of 1,048,576 64-bit words (1 megaword) of main memory, where each word also had eight parity bits for a total of 72 bits per word. Memory was spread across 16

interleaved memory In computing, interleaved memory is a design which compensates for the relatively slow speed of dynamic random-access memory (DRAM) or core memory, by spreading memory addresses evenly across memory banks. That way, contiguous memory reads and ...

banks, each with a 50 ns cycle time, allowing up to four words to be read per cycle. Smaller configurations could have 0.25 or 0.5 megawords of main memory. Maximum aggregate memory bandwidth was 638 Mbit/s. The main register set consisted of eight 64-bit scalar (S) registers and eight 24-bit address (A) registers. These were backed by a set of sixty-four registers each for S and A temporary storage known as T and B respectively, which could not be seen by the functional units. The vector system added another eight 64-element by 64-bit vector (V) registers, as well as a vector length (VL) and vector mask (VM). Finally, the system also included a 64-bit real-time clock register and four 64-bit instruction buffers that held sixty-four 16-bit instructions each. The hardware was set up to allow the vector registers to be fed at one word per cycle, while the address and scalar registers required two cycles. In contrast, the entire 16-word instruction buffer could be filled in four cycles. The Cray-1 had twelve pipelined functional units. The 24-bit address arithmetic was performed in an add unit and a multiply unit. The scalar portion of the system consisted of an add unit, a logical unit, a population count, a leading zero count unit and a shift unit. The vector portion consisted of add, logical and shift units. The floating point functional units were shared between the scalar and vector portions, and these consisted of add, multiply and reciprocal approximation units. The system had limited parallelism. It could issue one instruction per clock cycle, for a theoretical performance of 80 MIPS, but with vector floating-point multiplication and addition occurring in parallel theoretical performance was 160 MFLOPS. (The reciprocal approximation unit could also operate in parallel, but did not deliver a true floating-point result - two additional multiplications were needed to achieve a full division.) Since the machine was designed to operate on large data sets, the design also dedicated considerable circuitry to I/O. Earlier Cray designs at CDC had included separate computers dedicated to this task, but this was no longer needed. Instead the Cray-1 included four six-channel controllers, each of which was given access to main memory once every four cycles. The channels were 16 bits wide and included three control bits and four bits for error correction, so the maximum transfer speed was one word per 100 ns, or 500 thousand words per second for the entire machine. The initial model, the Cray-1A, weighed including the Freon refrigeration system. Configured with 1 million

words A word is a basic element of language that carries meaning, can be used on its own, and is uninterruptible. Despite the fact that language speakers often have an intuitive grasp of what a word is, there is no consensus among linguists on its ...

of main memory, the machine and its power supplies consumed about 115 kW of power; cooling and storage likely more than doubled this figure. A

Data General Data General Corporation was an early minicomputer firm formed in 1968. Three of the four founders were former employees of Digital Equipment Corporation (DEC). Their first product, 1969's Data General Nova, was a 16-bit minicomputer intended to ...

SuperNova S/200 minicomputer served as the maintenance control unit (MCU), which was used to feed the

Cray Operating System The Cray Operating System (COS) is a Cray Research operating system for its now-discontinued Cray-1 (1976) and Cray X-MP supercomputers. It succeeded the Chippewa Operating System (shipped with earlier Control Data Corporation CDC 6000 series a ...

into the system at boot time, to monitor the CPU during use, and optionally as a front-end computer. Most, if not all, Cray-1As were delivered using the follow-on Data General Eclipse as the MCU. The reliability of the CRAY-1A was very low by today's standards. At the

European Centre for Medium-Range Weather Forecasts The European Centre for Medium-Range Weather Forecasts (ECMWF) is an independent intergovernmental organisation supported by most of the nations of Europe. It is based at three sites: Shinfield Park, Reading, United Kingdom; Bologna, Italy; a ...

, which was one of the first customers, the mean time between hardware faults was reported to be 96 hours in 1979. Seymour Cray deliberately made design decisions that sacrificed reliability for speed, but improved his later designs after being questioned on this matter. Similarly, the Cray Operating System (COS) was fairly rudimentary, hardly tested and updated weekly or even daily in the early days.

Cray-1S

The Cray-1S, announced in 1979, was an improved Cray-1 that supported a larger main memory of 1, 2 or 4 million words. The larger main memory was made possible through the use of 4,096 x 1-bit bipolar RAM ICs with a 25 ns access time. The Data General minicomputers were optionally replaced with an in-house 16-bit design running at 80 MIPS. The I/O subsystem was separated from the main machine, connected to the main system via a 6 Mbit/s control channel and a 100 Mbit/s High Speed Data Channel. This separation made the 1S look like two "half Crays" separated by a few feet, which allowed the I/O system to be expanded as needed. Systems could be bought in a variety of configurations from the S/500 with no I/O and 0.5 million words of memory to the S/4400 with four I/O processors and 4 million words of memory.

Cray-1M

The Cray-1M, announced in 1982, replaced the Cray-1S. It had a faster 12 ns cycle time and used less expensive MOS RAM in the main memory. The 1M was supplied in only three versions, the M/1200 with 1 million words in 8 banks, or the M/2200 and M/4200 with 2 or 4 million words in 16 banks. All of these machines included two, three or four I/O processors, and the system added an optional second High Speed Data Channel. Users could add a Solid-state Storage Device with 8 to 32 million words of MOS RAM.

Software

In 1978, the first standard software package for the Cray-1 was released, consisting of three main products: *

(COS) (later machines would run

UNICOS UNICOS is a range of Unix and later Linux operating system (OS) variants developed by Cray for its supercomputers. UNICOS is the successor of the Cray Operating System (COS). It provides network clustering and source code compatibility layers fo ...

, Cray's

UNIX Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

flavor) * Cray Assembly Language (CAL) * Cray FORTRAN (CFT), the first automatically vectorizing Fortran compiler The

United States Department of Energy The United States Department of Energy (DOE) is an executive department of the U.S. federal government that oversees U.S. national energy policy and energy production, the research and development of nuclear power, the military's nuclear w ...

funded sites from

Los Alamos Scientific Laboratory Los Alamos National Laboratory (often shortened as Los Alamos and LANL) is one of the sixteen research and development laboratories of the United States Department of Energy (DOE), located a short distance northwest of Santa Fe, New Mexico, in ...

Sandia National Laboratories Sandia National Laboratories (SNL), also known as Sandia, is one of three research and development laboratories of the United States Department of Energy's National Nuclear Security Administration (NNSA). Headquartered in Kirtland Air Force B ...

and the

National Science Foundation The U.S. National Science Foundation (NSF) is an Independent agencies of the United States government#Examples of independent agencies, independent agency of the Federal government of the United States, United States federal government that su ...

centers (for high-energy physics) represented the second largest block with LLL's Cray Time Sharing System (CTSS). CTSS was written in a dynamic memory Fortran, first named LRLTRAN, which ran on

s, renamed CVC (pronounced "Civic") when vectorization for the Cray-1 was added. Cray Research attempted to support these sites accordingly. These software choices had influences on later

minisupercomputer Minisupercomputers constituted a short-lived class of computers that emerged in the mid-1980s, characterized by the combination of vector processing and small-scale multiprocessing. As scientific computing using vector processors became more popul ...

s, also known as " crayettes". NCAR has its own operating system (NCAROS). The

National Security Agency The National Security Agency (NSA) is an intelligence agency of the United States Department of Defense, under the authority of the director of national intelligence (DNI). The NSA is responsible for global monitoring, collection, and proces ...

developed its own operating system (Folklore) and language (IMP with ports of Cray Pascal and C and Fortran 90 later) Libraries started with Cray Research's own offerings and

Netlib Netlib is a repository of software for scientific computing maintained by AT&T, Bell Laboratories, the University of Tennessee and Oak Ridge National Laboratory. Netlib comprises many separate programs and libraries. Most of the code is written in ...

. Other operating systems existed, but most languages tended to be Fortran or Fortran-based.

Bell Laboratories Nokia Bell Labs, commonly referred to as ''Bell Labs'', is an American industrial research and development company owned by Finnish technology company Nokia. With headquarters located in Murray Hill, New Jersey, the company operates several lab ...

, as proof of both portability concept and circuit design, moved the first C compiler to their Cray-1 (non-vectorizing). This act would later give CRI a six-month head start on the

Unix port to ETA Systems' detriment, and

Lucasfilm Lucasfilm Ltd. LLC is an American film and television production company founded by filmmaker George Lucas in December 10, 1971 in San Rafael, California, and later moved to San Francisco in 2005. It is best known for creating and producing th ...

's first computer generated test film, '' The Adventures of André & Wally B.''. Application software generally tends to be either classified (''e.g.'' nuclear code, cryptanalytic code) or proprietary (''e.g.'' petroleum reservoir modeling). This was because little software was shared between customers and university customers. The few exceptions were climatological and meteorological programs until the NSF responded to the Japanese Fifth Generation Computer Systems project and created its supercomputer centers. Even then, little code was shared. Partly because Cray were interested in the publicity, they supported the development of

Cray Blitz Cray Blitz was a computer chess program written by Robert Hyatt, Harry L. Nelson, and Albert Gower to run on the Cray supercomputer. It was derived from "Blitz" a program that Hyatt started to work on as an undergraduate. "Blitz" played its first ...

which won the fourth (1983) and fifth (1986)

World Computer Chess Championship World Computer Chess Championship (WCCC) was an event held periodically from 1974 to 2024 where computer chess engines compete against each other. The event is organized by the ''International Computer Games Association'' (ICGA, until 2002 ICCA). I ...

, as well as the 1983 and 1984

North American Computer Chess Championship The North American Computer Chess Championship was a computer chess championship held from 1970 to 1994. It was organised by the Association for Computing Machinery and by Monty Newborn, professor of computer science at McGill University. It was o ...

. The program, Chess, that dominated in the 1970s ran on Control Data Corporation supercomputers.

Museums

Cray-1s are on display at the following locations: * Bradbury Science Museum in

Los Alamos, New Mexico Los Alamos (, meaning ''The Poplars'') is a census-designated place in Los Alamos County, New Mexico, United States, that is recognized as one of the development and creation places of the Nuclear weapon, atomic bomb—the primary objective of ...

* Chippewa Falls Museum of Industry and Technology in

Chippewa Falls, Wisconsin Chippewa Falls () is a city located on the Chippewa River (Wisconsin), Chippewa River in Chippewa County, Wisconsin, United States. The population was 14,731 in the 2020 United States census, 2020 census. Incorporated as a city in 1869, it is the ...

*The Cray Inc. offices at Cray Plaza in

St. Paul, Minnesota Saint Paul (often abbreviated St. Paul) is the capital city of the U.S. state of Minnesota and the county seat of Ramsey County. As of the 2020 census, the city had a population of 311,527, making it Minnesota's second-most populous city a ...

Computer History Museum The Computer History Museum (CHM) is a computer museum in Mountain View, California. The museum presents stories and artifacts of Silicon Valley and the Information Age, and explores the Digital Revolution, computing revolution and its impact ...

Mountain View, California Mountain View is a city in Santa Clara County, California, United States, part of the San Francisco Bay Area. Named for its views of the Santa Cruz Mountains, the population was 82,376 at the 2020 United States census, 2020 census. Mountain V ...

* Mimms Museum of Technology and Art in

Roswell, Georgia Roswell is a city in northern Fulton County, Georgia, United States. At the official 2020 census, the city had a population of 92,883, making Roswell the state's ninth largest city. A suburb of Atlanta, Roswell has an affluent National Registe ...

has four Cray-1s, plus other Cray computers * DigiBarn Computer Museum *

Deutsches Museum The Deutsches Museum (''German Museum'', officially (English: ''German Museum of Masterpieces of Science and Technology'')) in Munich, Germany, is the world's largest museum of science museum, science and technology museum, technology, with a ...

Munich Munich is the capital and most populous city of Bavaria, Germany. As of 30 November 2024, its population was 1,604,384, making it the third-largest city in Germany after Berlin and Hamburg. Munich is the largest city in Germany that is no ...

ETH Zurich ETH Zurich (; ) is a public university in Zurich, Switzerland. Founded in 1854 with the stated mission to educate engineers and scientists, the university focuses primarily on science, technology, engineering, and mathematics. ETH Zurich ran ...

- Eidgenössische Technische Hochschule

Zürich Zurich (; ) is the list of cities in Switzerland, largest city in Switzerland and the capital of the canton of Zurich. It is in north-central Switzerland, at the northwestern tip of Lake Zurich. , the municipality had 448,664 inhabitants. The ...

Switzerland Switzerland, officially the Swiss Confederation, is a landlocked country located in west-central Europe. It is bordered by Italy to the south, France to the west, Germany to the north, and Austria and Liechtenstein to the east. Switzerland ...

* Living Computers: Museum + Labs in

Seattle, Washington Seattle ( ) is the List of municipalities in Washington, most populous city in the U.S. state of Washington (state), Washington and in the Pacific Northwest region of North America. With a population of 780,995 in 2024, it is the List of Unit ...

National Air and Space Museum The National Air and Space Museum (NASM) of the Smithsonian Institution is a museum in Washington, D.C., in the United States, dedicated to history of aviation, human flight and space exploration. Established in 1946 as the National Air Museum, ...

Washington, D.C. Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and federal district of the United States. The city is on the Potomac River, across from Virginia, and shares land borders with ...

* Musée Bolo in

Lausanne Lausanne ( , ; ; ) is the capital and largest List of towns in Switzerland, city of the Swiss French-speaking Cantons of Switzerland, canton of Vaud, in Switzerland. It is a hilly city situated on the shores of Lake Geneva, about halfway bet ...

* The National Museum of Computing at

Bletchley Park Bletchley Park is an English country house and Bletchley Park estate, estate in Bletchley, Milton Keynes (Buckinghamshire), that became the principal centre of Allies of World War II, Allied World War II cryptography, code-breaking during the S ...

Science Museum A science museum is a museum devoted primarily to science. Older science museums tended to concentrate on static displays of objects related to natural history, paleontology, geology, Industry (manufacturing), industry and Outline of industrial ...

London London is the Capital city, capital and List of urban areas in the United Kingdom, largest city of both England and the United Kingdom, with a population of in . London metropolitan area, Its wider metropolitan area is the largest in Wester ...

Swedish National Museum of Science and Technology The National Museum of Science and Technology () is a museum in Stockholm. It is Sweden’s largest museum of technology, and has a national charter to be responsible for preserving the Swedish cultural heritage related to technological and in ...

in Stockholm, SwedenTM44354 Dator Cray Research, Inc. Cray Research, Inc. 1976 SAAB Aerospace
, p. 52, Datorföremål+på+TM.pdf. Retrieved 2012-05-15. * System Source Computer Museum in

Hunt Valley, Maryland Hunt Valley is an unincorporated area, unincorporated community in Baltimore County, Maryland, Baltimore County, Maryland, United States, near the site of the Maryland Hunt Cup Steeplechase (horse racing), Steeplechase. It lies just north of th ...

has a Cray-1, a Cray 1-s, and other Cray computers * Valladolid Science Museum in Spain.

Other images of the Cray-1

File:Cray 1 IMG 9126.jpg, Cray-1 with internals exposed at EPFL File:Cray-1-p1010225.jpg, Logic boards File:Cray-1-p1010227.jpg, Inside of the tower File:Cray-1-p1010237.jpg, Cooling system File:Cray-1-p1010230.jpg, Top of the casing File:Cray-1-p1010233.jpg, Close-up of logic boards File:Cray-1A-A1621b.jpg, Cray-1A power supply detail File:Cray-1 (1).jpg, Cray-1 at

File:Cray-1-Computer History Museum-20070512.jpg, Cray-1 at

File:Cray-1-deutsches-museum.jpg, Cray-1 at

File:Cray1LondonScienceMuseum.jpg, The Cray-1 at the

Science Museum, London The Science Museum is a major museum on Exhibition Road in South Kensington, London. It was founded in 1857 and is one of the city's major tourist attractions, attracting 3.3 million visitors annually in 2019. Like other publicly funded ...

File:Cray-1 at Computer Museum of America.jpg, Cray-1 at the Mimms Museum of Technology and Art, Roswell, Georgia, US File:Computer Museum of America (64).jpg, Logic boards File:Computer Museum of America (32).jpg, Some of the 50 miles of wiring File:Seymour_Cray.jpg, Seymour Cray with his Cray-1

References

External links

''CRAY-1 Computer System Hardware Reference Manual'', Publication No. 2240004 Rev.C 11/77 (first three chapters)
– Fro
DigiBarn
/ Ed Thelen
''CRAY-1 Computer System Hardware Reference Manual'', Publication No. 2240004 Rev.C 11/77 (full, scanned, PDF)Collection of on-line Cray manuals & documentation @ BitsaversCray Channels Magazine @ The Centre for Computing HistoryCray Manuals & Documentation @ The Centre for Computing HistoryCray Users Group Publications @ The Centre for Computing HistoryNCAR Supercomputer GalleryVerilog definition of Cray-1A CPU logic
{{Cray computers 1 Vector supercomputers Computer-related introductions in 1976 64-bit computers