Cray Inc. is an American supercomputer manufacturer headquartered in Seattle, Washington. It manufactures systems for data storage and analytics. Several Cray supercomputer systems are listed in the TOP500, which ranks the most powerful supercomputers in the world. Cray manufactures its products in Chippewa Falls, where its founder, Seymour Cray, was born and raised; the company has offices in Bloomington and numerous other sales, engineering, R&D locations around the world. The company's predecessor, Cray Research, Inc. was founded in 1972 by computer designer Seymour Cray. Seymour Cray went on to form the spin-off Cray Computer Corporation, in 1989, which went bankrupt in 1995, while Cray Research was bought by SGI the next year. Cray Inc. was formed in 2000 when Tera Computer Company purchased the Cray Research Inc. business from SGI and adopted the name of its acquisition. Seymour Cray began working in the computing field in 1950 when he joined Engineering Research Associates in Saint Paul, Minnesota.
There, he helped to create the ERA 1103. ERA became part of UNIVAC, began to be phased out, he left the company in 1960. He worked out of the CDC headquarters in Minneapolis, but grew upset by constant interruptions by managers, he set up a lab at his home town in Chippewa Falls, about 85 miles to the east. Cray had a string of successes at CDC, including the CDC 6600 and CDC 7600; when CDC ran into financial difficulties in the late 1960s, development funds for Cray's follow-on CDC 8600 became scarce. When he was told the project would have to be put "on hold" in 1972, Cray left to form his own company, Cray Research Inc. Copying the previous arrangement, Cray kept the research and development facilities in Chippewa Falls, put the business headquarters in Minneapolis; the company's first product, the Cray-1 supercomputer, was a major success because it was faster than all other computers at the time. The first system was sold within a month for US$8.8 million. Seymour Cray continued working, this time on the Cray-2, though it only ended up being marginally faster than the Cray X-MP, developed by another team at the company.
Cray soon left the CEO position to become an independent contractor. He started a new VLSI technology lab for the Cray-2 in Boulder, Cray Laboratories, in 1979, which closed in 1982. However, the changing political climate resulted in poor sales prospects. Only one Cray-3 was delivered, a number of follow-on designs were never completed; the company filed for bankruptcy in 1995. CCC's remains began Cray's final corporation, SRC Computers, Inc. Cray Research continued development along a separate line of computers with lead designer Steve Chen and the Cray X-MP. After Chen's departure, the Cray Y-MP, Cray C90 and Cray T90 were developed on the original Cray-1 architecture but achieved much greater performance via multiple additional processors, faster clocks, wider vector pipes; the uncertainty of the Cray-2 project gave rise to a number of Cray-object-code compatible "Crayette" firms: Scientific Computer Systems, American Supercomputer and one other firm. These firms did not mean to compete against Cray and therefore attempted less expensive, slower CMOS versions of the X-MP with the release of the COS operating system and the CFT Fortran compiler.
A series of massively parallel computers from Thinking Machines, Kendall Square Research, Intel Supercomputing Systems Division, nCUBE, MasPar and Meiko Scientific took over the 1980s high performance market. At first, Cray Research denigrated such approaches by complaining that developing software to use the machines was difficult – a true complaint in the era of the ILLIAC IV, but becoming less so each day. Cray realized that the approach was the only way forward and started a five-year project to capture the lead in this area: the plan's result was the DEC Alpha-based Cray T3D and Cray T3E series, which left Cray as the only remaining supercomputer vendor in the market besides NEC by 2000. Most sites with a Cray installation were considered a member of the "exclusive club" of Cray operators. Cray computers were considered quite prestigious because Crays were expensive machines, the number of units sold was small compared to ordinary mainframes; this perception extended to countries as well: to boost the perception of exclusivity, Cray Research's marketing department had promotional neckties made with a mosaic of tiny national flags illustrating the "club of Cray-operating countries".
New vendors introduced small supercomputers, known as minisupercomputers during the late 1980s and early 1990s, which out-competed low-end Cray machines in the market. The Convex Computer series, as well as a number of small-scale parallel machines from companies like Pyramid Technology and Alliant Computer Systems were popular. One such vendor was Supertek, whose S-1 machine was an air-cooled CMOS implementation of the X-MP processor. Cray purchased Supertek in 1990 and sold the S-1 as the Cray XMS, but the machine proved problematic.
National Cryptologic Museum
The National Cryptologic Museum is an American museum of cryptologic history, affiliated with the National Security Agency. The first public museum in the U. S. Intelligence Community, NCM is located in the former Colony Seven Motel, just two blocks from the NSA headquarters at Fort George G. Meade in Maryland; the museum opened to the public on December 16, 1993, now hosts about 50,000 visitors annually from all over the world. The NCM is open Monday to Friday, 9:00 AM – 4:00 PM, as well as 10:00 a.m. – 2:00 p.m. on the first and third Saturdays of each month. It is closed on Sundays and all federal holidays, operates on NSA's emergency/weather closure schedule; the NCM includes a gift store whose operational hours coordinate with the museum's operational schedule and an unclassified library with weekday-only operating hours that reflect the museum's weekday operational schedule. The library includes over a dozen boxes of the files of Herbert Yardley, declassified Enigma messages, technical reports, books including how to crack the Data Encryption Standard using Deep Crack.
The National Vigilance Park was next to the museum, where three reconnaissance aircraft were displayed. A U. S. Army Beechcraft RU-8D Seminole reconnaissance plane represents the Army Airborne Signals Intelligence contribution in the Vietnam War. A Lockheed C-130 Hercules transport, modified to look like a reconnaissance-configured C-130A, memorialized a U. S. Air Force aircraft shot down over Soviet Armenia during the Cold War; the park contained a U. S. Navy Douglas EA-3B Skywarrior, commemorating a mission in the Mediterranean on January 25, 1987 in which all seven crew members died; the NCM is open to the public and admission is free. Donations to the NCM Foundation are accepted. Photography is allowed inside the museum, but flash photography is prohibited in certain areas of the museum due to the age of some of the artifacts; the NCM collection contains thousands of artifacts, including numerous working World War II German Enigma machines, a Navy Bombe used to break it. Displays discuss the history of American cryptology and the people, machines and locations concerned.
Housing NSA artifacts for viewing by employees, the museum developed into a collection of U. S. cryptologic history, with some artifacts dating back to pre-American Revolutionary War times. In addition to exhibits covering equipment used to encrypt and secure information, the museum features exhibits on the people who contributed to cryptography in America, such as George Washington, the Native American code talkers, the Navy WAVES. Collections are divided into four major groupings: Early Cryptology, which deals with cryptologic history prior to the formation of NSA, with exhibits dating back to the 16th century forward to the early 1950s, focusing on artifacts from the Founding Fathers of the United States, the American Civil War, the United States Army Code talkers, World War I, World War II, the Korean War Cold War/Information Age, which deals with cryptology and cryptanalysis on both sides of the Cold War, the early years of NSA, the rise of the modern age of computers, including the development of supercomputers Information Assurance, which deals with the rise of satellite technology, secure voice communications, tamper-evident technologies, use of biometrics in data protection Memorial Hall, one side of which features the NSA Hall of Honor, the other side of which features exhibits honoring those who lost their lives in cryptologic missions represented by the aircraft at NVP as well as others who lost their lives in cryptologic service to America In addition, there are galleries throughout NCM focusing on the roles of women and African-Americans in cryptologic history, the variety of languages in use throughout the world, the code used by hobos to share information in the late 19th and early 20th centuries.
The NCM includes an unclassified library of books and other materials relating to the history of cryptography and cryptology as well. The library is open on weekdays; the library is non-circulating. Patrons needing extensive or rare materials for research are encouraged to contact the museum to schedule an appointment with the librarian; the size of NCM's library nearly doubled with the donation of an extensive collection of papers and other artifacts related to codes and ciphers from cryptologic historian and author David Kahn. The donation was formally dedicated by the NCM during a recognition ceremony for Dr. Kahn on October 26, 2010; the museum offers tours for members of the public, both scheduled and walk-in, that describe cryptology's impact on history and jobs in the field. Tours are led by docents. Groups of six persons or more are requested to contact the museum in advance to schedule tours and ensure docent availability. In addition, the NCM offers educational field t
The DataVault was Thinking Machines' mass storage system. It stored five gigabytes of data, expandable to ten gigabytes with transfer rates of 40 megabytes per second. Eight DataVaults could be operated in parallel for a combined data transfer rate of 320 megabytes per second for up to 80 gigabytes of data; each DataVault unit stored its data in an array of 39 individual disk drives with data was spread across the drives. Each 64-bit data chunk received from the I/O bus was split into two 32-bit words. After verifying parity, the DataVault controller added 7 bits of Error Correcting Code and stored the resulting 39 bits on 39 individual drives. Subsequent failure of any one of the 39 drives would not impair reading of the data, since the ECC code allows any single bit error to be detected and corrected. Although operation is possible with a single failed drive, three spare drives were available to replace failed units until they are repaired; the ECC codes permit 100% recovery of the data on any one failed disk, allowing a new copy of this data to be reconstructed and written onto the replacement disk.
Once this recovery is complete, the data base is considered to be healed. In today's terminology this would be labeled a RAID-2 subsystem, it shipped before the label RAID was formed. The DataVault was a striking example of industrial design. Instead of the usual rectilinear box, the cabinet had a gentle curve that made it look like an information desk or a bartender's station. US patent 4899342, "Method and apparatus for operating multi-unit array of memories", issued 1990-02-06, assigned to Thinking Machines Corporation
Massachusetts the Commonwealth of Massachusetts, is the most populous state in the New England region of the northeastern United States. It borders on the Atlantic Ocean to the east, the states of Connecticut and Rhode Island to the south, New Hampshire and Vermont to the north, New York to the west; the state is named after the Massachusett tribe, which once inhabited the east side of the area, is one of the original thirteen states. The capital of Massachusetts is Boston, the most populous city in New England. Over 80% of Massachusetts's population lives in the Greater Boston metropolitan area, a region influential upon American history and industry. Dependent on agriculture and trade, Massachusetts was transformed into a manufacturing center during the Industrial Revolution. During the 20th century, Massachusetts's economy shifted from manufacturing to services. Modern Massachusetts is a global leader in biotechnology, higher education and maritime trade. Plymouth was the site of the second colony in New England after Popham Colony in 1607 in what is now Maine.
Plymouth was founded in 1620 by passengers of the Mayflower. In 1692, the town of Salem and surrounding areas experienced one of America's most infamous cases of mass hysteria, the Salem witch trials. In 1777, General Henry Knox founded the Springfield Armory, which during the Industrial Revolution catalyzed numerous important technological advances, including interchangeable parts. In 1786, Shays' Rebellion, a populist revolt led by disaffected American Revolutionary War veterans, influenced the United States Constitutional Convention. In the 18th century, the Protestant First Great Awakening, which swept the Atlantic World, originated from the pulpit of Northampton preacher Jonathan Edwards. In the late 18th century, Boston became known as the "Cradle of Liberty" for the agitation there that led to the American Revolution; the entire Commonwealth of Massachusetts has played a powerful commercial and cultural role in the history of the United States. Before the American Civil War, Massachusetts was a center for the abolitionist and transcendentalist movements.
In the late 19th century, the sports of basketball and volleyball were invented in the western Massachusetts cities of Springfield and Holyoke, respectively. In 2004, Massachusetts became the first U. S. state to recognize same-sex marriage as a result of the decision in Goodridge v. Department of Public Health by the Massachusetts Supreme Judicial Court. Many prominent American political dynasties have hailed from the state, including the Adams and Kennedy families. Harvard University in Cambridge is the oldest institution of higher learning in the United States, with the largest financial endowment of any university, Harvard Law School has educated a contemporaneous majority of Justices of the Supreme Court of the United States. Kendall Square in Cambridge has been called "the most innovative square mile on the planet", in reference to the high concentration of entrepreneurial start-ups and quality of innovation which have emerged in the vicinity of the square since 2010. Both Harvard University and the Massachusetts Institute of Technology in Cambridge, have been ranked among the most regarded academic institutions in the world.
Massachusetts' public-school students place among the top tier in the world in academic performance, the state has been ranked as one of the top states in the United States for citizens to live in, as well as one of the most expensive. The Massachusetts Bay Colony was named after the indigenous population, the Massachusett derived from a Wôpanâak word muswach8sut, segmented as mus "big" + wach8 "mountain" + -s "diminutive" + -ut "locative", it has been translated as "near the great hill", "by the blue hills", "at the little big hill", or "at the range of hills", referring to the Blue Hills, or in particular the Great Blue Hill, located on the boundary of Milton and Canton. Alternatively, Massachusett has been represented as Moswetuset—from the name of the Moswetuset Hummock in Quincy, where Plymouth Colony commander Myles Standish, hired English military officer, Squanto, part of the now disappeared Patuxet band of the Wampanoag peoples, met Chief Chickatawbut in 1621; the official name of the state is the "Commonwealth of Massachusetts".
While this designation is part of the state's official name, it has no practical implications. Massachusetts has powers within the United States as other states, it may have been chosen by John Adams for the second draft of the Massachusetts Constitution because unlike the word "state", "commonwealth" at the time had the connotation of a republic, in contrast to the monarchy the former American colonies were fighting against. Massachusetts was inhabited by tribes of the Algonquian language family such as the Wampanoag, Nipmuc, Pocomtuc and Massachusett. While cultivation of crops like squash and corn supplemented their diets, these tribes were dependent on hunting and fishing for most of their food. Villages consisted of lodges called wigwams as well as longhouses, tribes were led by male or female elders known as sachems. In the early 1600s, after contact had been made with Europeans, large numbers of the indigenous peoples in the northeast of what is now the United States were killed by virgin soil epidemics such as smallpox, measles and leptospirosis.
Between 1617 and 1619, smallpox killed ap
Parallel computing is a type of computation in which many calculations or the execution of processes are carried out simultaneously. Large problems can be divided into smaller ones, which can be solved at the same time. There are several different forms of parallel computing: bit-level, instruction-level and task parallelism. Parallelism has long been employed in high-performance computing, but it's gaining broader interest due to the physical constraints preventing frequency scaling; as power consumption by computers has become a concern in recent years, parallel computing has become the dominant paradigm in computer architecture in the form of multi-core processors. Parallel computing is related to concurrent computing—they are used together, conflated, though the two are distinct: it is possible to have parallelism without concurrency, concurrency without parallelism. In parallel computing, a computational task is broken down into several many similar sub-tasks that can be processed independently and whose results are combined afterwards, upon completion.
In contrast, in concurrent computing, the various processes do not address related tasks. Parallel computers can be classified according to the level at which the hardware supports parallelism, with multi-core and multi-processor computers having multiple processing elements within a single machine, while clusters, MPPs, grids use multiple computers to work on the same task. Specialized parallel computer architectures are sometimes used alongside traditional processors, for accelerating specific tasks. In some cases parallelism is transparent to the programmer, such as in bit-level or instruction-level parallelism, but explicitly parallel algorithms those that use concurrency, are more difficult to write than sequential ones, because concurrency introduces several new classes of potential software bugs, of which race conditions are the most common. Communication and synchronization between the different subtasks are some of the greatest obstacles to getting good parallel program performance.
A theoretical upper bound on the speed-up of a single program as a result of parallelization is given by Amdahl's law. Traditionally, computer software has been written for serial computation. To solve a problem, an algorithm is implemented as a serial stream of instructions; these instructions are executed on a central processing unit on one computer. Only one instruction may execute at a time—after that instruction is finished, the next one is executed. Parallel computing, on the other hand, uses multiple processing elements to solve a problem; this is accomplished by breaking the problem into independent parts so that each processing element can execute its part of the algorithm with the others. The processing elements can be diverse and include resources such as a single computer with multiple processors, several networked computers, specialized hardware, or any combination of the above. Parallel computing was used for scientific computing and the simulation of scientific problems in the natural and engineering sciences, such as meteorology.
This led to the design of parallel software, as well as high performance computing. Frequency scaling was the dominant reason for improvements in computer performance from the mid-1980s until 2004; the runtime of a program is equal to the number of instructions multiplied by the average time per instruction. Maintaining everything else constant, increasing the clock frequency decreases the average time it takes to execute an instruction. An increase in frequency thus decreases runtime for all compute-bound programs. However, power consumption P by a chip is given by the equation P = C × V 2 × F, where C is the capacitance being switched per clock cycle, V is voltage, F is the processor frequency. Increases in frequency increase the amount of power used in a processor. Increasing processor power consumption led to Intel's May 8, 2004 cancellation of its Tejas and Jayhawk processors, cited as the end of frequency scaling as the dominant computer architecture paradigm. To deal with the problem of power consumption and overheating the major central processing unit manufacturers started to produce power efficient processors with multiple cores.
The core is the computing unit of the processor and in multi-core processors each core is independent and can access the same memory concurrently. Multi-core processors have brought parallel computing to desktop computers, thus parallelisation of serial programmes has become a mainstream programming task. In 2012 quad-core processors became standard for desktop computers, while servers have 10 and 12 core processors. From Moore's law it can be predicted that the number of cores per processor will double every 18–24 months; this could mean that after 2020 a typical processor will have hundreds of cores. An operating system can ensure that different tasks and user programmes are run in parallel on the available cores. However, for a serial software programme to take full advantage of the multi-core architecture the programmer needs to restructure and parallelise the code. A speed-up of application software runtime will no longer be achieved through frequency scaling, instead programmers will need to parallelise their software code to take
École Polytechnique Fédérale de Lausanne
The École polytechnique fédérale de Lausanne is a research institute and university in Lausanne, that specializes in natural sciences and engineering. It is one of the two Swiss Federal Institutes of Technology, it has three main missions: education and technology transfer at the highest international level. EPFL is regarded as a world leading university; the QS World University Rankings ranks EPFL 12th in the world across all fields in their 2017/2018 ranking, whilst Times Higher Education World University Rankings ranks EPFL as the world's 11th best school for Engineering and Technology. EPFL is located in the French-speaking part of Switzerland. Associated with several specialised research institutes, the two universities form the Swiss Federal Institutes of Technology Domain, directly dependent on the Federal Department of Economic Affairs and Research. In connection with research and teaching activities, EPFL operates a nuclear reactor CROCUS, a Tokamak Fusion reactor, a Blue Gene/Q Supercomputer and P3 bio-hazard facilities.
The roots of modern-day EPFL can be traced back to the foundation of a private school under the name École spéciale de Lausanne in 1853 at the initiative of Lois Rivier, a graduate of the École Centrale Paris and John Gay, the professor and rector of the Académie de Lausanne. At its inception it had only 11 students and the offices was located at Rue du Valentin in Lausanne. In 1869, it became the technical department of the public Académie de Lausanne; when the Académie was reorganised and acquired the status of a university in 1890, the technical faculty changed its name to École d'ingénieurs de l'Université de Lausanne. In 1946, it was renamed the École polytechnique de l'Université de Lausanne. In 1969, the EPUL was separated from the rest of the University of Lausanne and became a federal institute under its current name. EPFL, like ETH Zurich, is thus directly controlled by the Swiss federal government. In contrast, all other universities in Switzerland are controlled by their respective cantonal governments.
Following the nomination of Patrick Aebischer as president in 2000, EPFL has started to develop into the field of life sciences. It absorbed the Swiss Institute for Experimental Cancer Research in 2008. In 1946, there were 360 students. In 1969, EPFL had 55 professors. In the past two decades the university has grown and as of 2012 14,000 people study or work on campus, about 9,300 of these being Bachelor, Master or PhD students; as EPFL first became a federal institute under its current name in 1969, with a student body of less than 1500, the university is included in the Times Higher Education list of top 100 universities under 50 years old. The environment at modern day EPFL is international with the school now attracting top students and researchers from all over the world. More than 125 countries are represented on the campus and the university has two official languages and English. Like every public university in Switzerland, EPFL is obliged to grant admission to every Swiss resident who took the maturité high-school certificate recognized by the Swiss Federation.
However, international students are required to have a final grade average of 80% or above of the maximum grade of the upper secondary school national system. As such, for Swiss students, EPFL is not selective in its undergraduate admission procedures; the real selection process happens during the first year of study. This period is called the propaedeutic cycle and the students must pass a block examination of all the courses taken during the first year at the end of the cycle. If the weighted average is insufficient, a student is required to retake the entire first year of coursework if they wish to continue their studies at the school. 50% of students fail the first year of study, many of them choose to drop out rather than repeat the first year. The failure rate for the propaedeutic cycle differs between fields of study, it is highest for Mathematics and Electrical Engineering majors where only 30–40% of students pass the first year. For foreign students, the selection procedure towards the undergraduate program is rather strict, since most undergraduate courses are taught in French, foreign students must provide documentation of having acquired a level B2 proficiency as measured on the CEF scale, though C1 proficiency is recommended.
As at all universities in Switzerland, the academic year is divided into two semesters. Regular time to reach graduation is six semesters for the Bachelor of Science degree and four additional semesters for the Master of Science degree. Though only 58% of the student's who manage to graduate are able to graduate within this time-period; the possibility to study abroad for one or two semesters is offered during the 3rd year of study under certain conditions as EPFL maintains several long-standing student exchange programs, such as the junior year engineering and science program with Carnegie Mellon University in the United States, as well as a graduate Aeronautics and Aerospace program with the ISAE in France. The final semester is dedicated to writing a thesis. Entrepreneurship is encouraged to foster a start-up culture among the student body as evident by the EPFL Innovation Park being an integral part of campus. Since 1997, 12 start-ups have been created per year on average by EPFL students and faculty.
In the year 2013, a total of 105 million CHF was raised by EPFL start-ups. The three most observed international university rankings, QS World University Rankings, Academic Ranking of World Universities and Times Higher Education Wor
VAX is a discontinued instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. The VAX-11/780, introduced on October 25, 1977, was the first of a range of popular and influential computers implementing that architecture. A 32-bit system with a complex instruction set computer architecture based on DEC's earlier PDP-11, VAX was designed to extend or replace DEC's various Programmed Data Processor ISAs; the VAX architecture's primary features were its orthogonal instruction set. VAX was succeeded by the DEC Alpha instruction set architecture. VAX has been perceived as the quintessential CISC ISA, with its large number of assembly-language-programmer-friendly addressing modes and machine instructions orthogonal architecture, instructions for complex operations such as queue insertion or deletion and polynomial evaluation; the name "VAX" originated as an acronym for virtual address extension, both because the VAX was seen as a 32-bit extension of the older 16-bit PDP-11 and because it was an early adopter of virtual memory to manage this larger address space.
Early versions of the VAX processor implement a "compatibility mode" that emulates many of the PDP-11's instructions, are in fact called VAX-11 to highlight this compatibility and that VAX-11 was an outgrowth of the PDP-11 family. Versions offloaded the compatibility mode and some of the less used CISC instructions to emulation in the operating system software; the VAX instruction set was designed to be orthogonal. When it was introduced, many programs were written in assembly language, so having a "programmer-friendly" instruction set was important. In time, as more programs were written in higher-level language, the instruction set became less visible, the only ones much concerned about it were compiler writers. One unusual aspect of the VAX instruction set is the presence of register masks at the start of each subprogram; these are arbitrary bit patterns that specify, when control is passed to the subprogram, which registers are to be preserved. Since register masks are a form of data embedded within the executable code, they can make linear parsing of the machine code difficult.
This can complicate optimization techniques. The "native" VAX operating system is Digital's VAX/VMS; the VAX architecture and OpenVMS operating system were "engineered concurrently" to take maximum advantage of each other, as was the initial implementation of the VAXcluster facility. Other VAX operating systems have included various releases of BSD UNIX up to 4.3BSD, Ultrix-32, VAXELN, Xinu. More NetBSD and OpenBSD have supported various VAX models and some work has been done on porting Linux to the VAX architecture. OpenBSD discontinued support for the architecture in September 2016; the first VAX model sold was the VAX-11/780, introduced on October 25, 1977 at the Digital Equipment Corporation's Annual Meeting of Shareholders. Bill Strecker, C. Gordon Bell's doctoral student at Carnegie Mellon University, was responsible for the architecture. Many different models with different prices, performance levels, capacities were subsequently created. VAX superminicomputers were popular in the early 1980s.
For a while the VAX-11/780 was used as a standard in CPU benchmarks. It was described as a one-MIPS machine, because its performance was equivalent to an IBM System/360 that ran at one MIPS, the System/360 implementations had been de facto performance standards; the actual number of instructions executed in 1 second was about 500,000, which led to complaints of marketing exaggeration. The result was the definition of a "VAX MIPS," the speed of a VAX-11/780. Within the Digital community the term VUP was the more common term, because MIPS do not compare well across different architectures; the related term cluster VUPs was informally used to describe the aggregate performance of a VAXcluster. The VAX-11/780 included a subordinate stand-alone LSI-11 computer that performed microcode load and diagnostic functions for the parent computer; this was dropped from subsequent VAX models. Enterprising VAX-11/780 users could therefore run three different Digital Equipment Corporation operating systems: VMS on the VAX processor, either RSX-11M or RT-11 on the LSI-11.
The VAX went through many different implementations. The original VAX 11/780 was implemented in TTL and filled a four-by-five-foot cabinet with a single CPU. CPU implementations that consisted of multiple ECL gate array or macrocell array chips included the VAX 8600 and 8800 superminis and the VAX 9000 mainframe class machines. CPU implementations that consisted of multiple MOSFET custom chips included the 8100 and 8200 class machines; the VAX 11-730 and 725 low-end machines were built using bit-slice components. The MicroVAX I represented a major transition within the VAX family. At the time of its design, it was not yet possible to implement the full VAX architecture as a single VLSI chip. Instead, the MicroVAX I was the first VAX implementation to move some of the more complex VAX instructions (such as th