1.
Supercomputer
–
A supercomputer is a computer with a high level of computing performance compared to a general-purpose computer. Performance of a supercomputer is measured in floating-point operations per second instead of instructions per second. As of 2015, there are supercomputers which can perform up to quadrillions of FLOPS and it tops the rankings in the TOP500 supercomputer list. Sunway TaihuLights emergence is also notable for its use of indigenous chips, as of June 2016, China, for the first time, had more computers on the TOP500 list than the United States. However, U. S. built computers held ten of the top 20 positions, in November 2016 the U. S. has five of the top 10, throughout their history, they have been essential in the field of cryptanalysis. The use of multi-core processors combined with centralization is an emerging trend, the history of supercomputing goes back to the 1960s, with the Atlas at the University of Manchester and a series of computers at Control Data Corporation, designed by Seymour Cray. These used innovative designs and parallelism to achieve superior computational peak performance, Cray left CDC in 1972 to form his own company, Cray Research. Four years after leaving CDC, Cray delivered the 80 MHz Cray 1 in 1976, the Cray-2 released in 1985 was an 8 processor liquid cooled computer and Fluorinert was pumped through it as it operated. It performed at 1.9 gigaflops and was the second fastest after M-13 supercomputer in Moscow. Fujitsus Numerical Wind Tunnel supercomputer used 166 vector processors to gain the top spot in 1994 with a speed of 1.7 gigaFLOPS per processor. The Hitachi SR2201 obtained a performance of 600 GFLOPS in 1996 by using 2048 processors connected via a fast three-dimensional crossbar network. The Intel Paragon could have 1000 to 4000 Intel i860 processors in various configurations, the Paragon was a MIMD machine which connected processors via a high speed two dimensional mesh, allowing processes to execute on separate nodes, communicating via the Message Passing Interface. Approaches to supercomputer architecture have taken dramatic turns since the earliest systems were introduced in the 1960s, early supercomputer architectures pioneered by Seymour Cray relied on compact innovative designs and local parallelism to achieve superior computational peak performance. However, in time the demand for increased computational power ushered in the age of massively parallel systems, supercomputers of the 21st century can use over 100,000 processors connected by fast connections. The Connection Machine CM-5 supercomputer is a parallel processing computer capable of many billions of arithmetic operations per second. Throughout the decades, the management of heat density has remained a key issue for most centralized supercomputers, the large amount of heat generated by a system may also have other effects, e. g. reducing the lifetime of other system components. There have been diverse approaches to management, from pumping Fluorinert through the system. Systems with a number of processors generally take one of two paths
2.
Computer cluster
–
A computer cluster consists of a set of loosely or tightly connected computers that work together so that, in many respects, they can be viewed as a single system. Unlike grid computers, computer clusters have each set to perform the same task. The components of a cluster are usually connected to each other through fast local area networks and they have a wide range of applicability and deployment, ranging from small business clusters with a handful of nodes to some of the fastest supercomputers in the world such as IBMs Sequoia. The desire to get more computing power and better reliability by orchestrating a number of low-cost commercial off-the-shelf computers has given rise to a variety of architectures, the computer clustering approach usually connects a number of readily available computing nodes via a fast local area network. g. Via a single system image concept, Computer clustering relies on a centralized management approach which makes the nodes available as orchestrated shared servers. It is distinct from other such as peer to peer or grid computing which also use many nodes. A computer cluster may be a simple system which just connects two personal computers, or may be a very fast supercomputer. A basic approach to building a cluster is that of a Beowulf cluster which may be built with a few computers to produce a cost-effective alternative to traditional high performance computing. An early project that showed the viability of the concept was the 133-node Stone Soupercomputer, the developers used Linux, the Parallel Virtual Machine toolkit and the Message Passing Interface library to achieve high performance at a relatively low cost. Although a cluster may consist of just a few personal computers connected by a simple network, greg Pfister has stated that clusters were not invented by any specific vendor but by customers who could not fit all their work on one computer, or needed a backup. Pfister estimates the date as some time in the 1960s, the first production system designed as a cluster was the Burroughs B5700 in the mid-1960s. This allowed up to four computers, each with one or two processors, to be tightly coupled to a common disk storage subsystem in order to distribute the workload. Unlike standard multiprocessor systems, each computer could be restarted without disrupting overall operation, the first commercial loosely coupled clustering product was Datapoint Corporations Attached Resource Computer system, developed in 1977, and using ARCnet as the cluster interface. Clustering per se did not really take off until Digital Equipment Corporation released their VAXcluster product in 1984 for the VAX/VMS operating system, the ARC and VAXcluster products not only supported parallel computing, but also shared file systems and peripheral devices. The idea was to provide the advantages of parallel processing, while maintaining data reliability, two other noteworthy early commercial clusters were the Tandem Himalayan and the IBM S/390 Parallel Sysplex. Within the same frame, while computer clusters used parallelism outside the computer on a commodity network. Following the success of the CDC6600 in 1964, the Cray 1 was delivered in 1976, while early supercomputers excluded clusters and relied on shared memory, in time some of the fastest supercomputers relied on cluster architectures. Computer clusters may be configured for different purposes ranging from general purpose business needs such as web-service support, in either case, the cluster may use a high-availability approach
3.
Cray-2
–
The Cray-2 is a supercomputer with four vector processors built with emitter-coupled logic and 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, the Cray-2 was replaced as the worlds fastest computer by the ETA-10G in 1990. With the successful launch of his famed Cray-1, Seymour Cray turned to the design of its successor. By 1979 he had become fed up with management interruptions in what was now a large company, and as he had done in the past, decided to resign his management post and move to form a new lab. As with his move to Chippewa Falls, Wisconsin from Control Data HQ in Minneapolis, Minnesota, Cray management understood his needs and supported his move to a new lab in Boulder. Working as an independent consultant at these new Cray Labs, he put together a team and this Lab would later close, and a decade later a new facility in Colorado Springs would open. The classic example of design is the CDC8600, which packed four CDC 7600-like machines based on ECL logic into a 1 x 1 meter cylinder. Unfortunately the density needed to achieve this cycle time led to the machines downfall, one solution to this problem, one that most computer vendors had already moved to, was to use integrated circuits instead of individual components. Each IC included a selection of components from a module pre-wired into a circuit by the construction process. If an IC did not work, another one would be tried, at the time the 8600 was being designed the simple MOSFET-based technology did not offer the speed Cray needed. Relentless improvements changed things by the mid-1970s, however, and the Cray-1 had been able to use newer ICs, in fact, the Cray-1 was actually somewhat faster than the 8600 because it packed considerably more logic into the system due to the ICs small size. Although IC design continued to improve, the size of the ICs was constrained largely by mechanical limits. In order to gain another 10-fold increase in performance over the Cray-1, the goal Cray aimed for, another design problem was the increasing performance gap between the processor and main memory. In the era of the CDC6600 memory ran at the speed as the processor. Cray solved this by adding ten smaller computers to the system, allowing them to deal with the external storage. Adding four processors simply made this problem worse and it was the foreground processors task to run the computer, handling storage and making efficient use of the multiple channels into main memory. It drove the background processors by passing in the instructions they should run via eight 16 word buffers, modern CPUs use a variation of this design as well, although the foreground processor is now referred to as the load/store unit and is not a complete machine unto its own. Main memory banks were arranged in quadrants to be accessed at the same time, the downside to this approach is that the cost of setting up the scatter/gather unit in the foreground processor was fairly high
4.
UNIX System V
–
UNIX System V is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983, four major versions of System V were released, numbered 1,2,3, and 4. It was the source of common commercial Unix features. System V is sometimes abbreviated to SysV, as of 2012, the Unix market is divided between three System V variants, IBMs AIX, Hewlett-Packards HP-UX and Oracles Solaris. System V was the successor to 1982s UNIX System III, while AT&T sold their own hardware that ran System V, most customers instead ran a version from a reseller, based on AT&Ts reference implementation. A standards document called the System V Interface Definition outlined the default features, in the 1980s and early-1990s, System V was considered one of the two major versions of UNIX, the other being the Berkeley Software Distribution. Historically, BSD was also commonly called BSD Unix or Berkeley Unix, the dispute had several levels, some technical and some cultural. The divide was roughly between longhairs and shorthairs, programmers and technical people tended to line up with Berkeley and BSD, more business-oriented types with AT&T and System V. While HP, IBM and others chose System V as the basis for their Unix offerings, other such as Sun Microsystems. Throughout its development, though, System V was infused with features from BSD, since the early 1990s, due to standardization efforts such as POSIX and the commercial success of Linux, the division between System V and BSD has become less important. System V, known inside Bell Labs as Unix 5.0, there was never an external release of Unix 4.0, which would have been System IV. This first release of System V was developed by AT&Ts UNIX Support Group, System V also included features such as the vi editor and curses from 4.1 BSD, developed at the University of California, Berkeley, it also improved performance by adding buffer and inode caches. It also added support for communication using messages, semaphores. SVR1 ran on DEC PDP-11 and VAX minicomputers, System V Release 2 was released in April,1984. It added shell functions and the SVID, new kernel features included record and file locking, demand paging, and copy on write. The concept of the base was formalized, and the DEC VAX-11/780 was chosen for this release. The porting base is the original version of a release. Educational source licenses for SVR2 were offered by AT&T for US$800 for the first CPU, a commercial source license was offered for $43,000, with three months of support, and a $16,000 price per additional CPU
5.
Cray X-MP
–
The Cray X-MP is a supercomputer designed, built and sold by Cray Research. It was announced in 1982 as the cleaned up successor to the 1975 Cray-1, the principal designer was Steve Chen. The X-MPs main improvement over the Cray-1 was that it was a parallel vector processor. It housed two CPUs in a mainframe that was identical in outside appearance to the Cray-1. The X-MP CPU had a faster 9.5 nanosecond clock cycle and it was built from bipolar gate-array integrated circuits containing 16 emitter-coupled logic gates each. The CPU was very similar to the Cray-1 CPU in architecture, each CPU had a theoretical peak performance of 200 MFLOPS, for a peak system performance of 400 MFLOPS. The X-MP initially supported 2 million 64-bit words of memory in 16 banks. Memory bandwidth was significantly improved over the Cray-1—instead of one port for both reads and writes, there were now two read ports, one port, and one dedicated to I/O. The main memory was built from 4 Kbit bipolar SRAM ICs, CMOS memory versions of the Cray-1M were renamed Cray X-MP/1s. This configuration was first used for Cray Researchs UNIX port, in 1984, improved models of the X-MP were announced, consisting of one, two, and four-processor systems with 4 and 8 million word configurations. The top-end system was the X-MP/48, which contained four CPUs with a peak system performance of over 800 MFLOPS and 8 million words of memory. The CPUs in these models introduced vector gather/scatter memory reference instructions to the product line, the amount of main memory supported was increased to a maximum of 16 million words, depending on the model. The main memory was built from bipolar or MOS SRAM ICs, the system initially ran the proprietary Cray Operating System and was object-code compatible with the Cray-1. A UNIX System V derivative initially named CX-OS and finally renamed UniCOS ran through a guest operating system facility, UniCOS became the main OS from 1986 onwards. The DOE ran the Cray Time Sharing System OS instead, see the Software section for the Cray 1 for a more detailed elaboration of software as X-MPs and 1s were mostly compatible. Cray Research announced the X-MP Extended Architecture series in 1986, the EA series CPU had an 8.5 ns clock cycle, and was built from macrocell array and gate array ICs. The EA series extended the width of the A and B registers to 32 bits and performed 32-bit address arithmetic, the largest configuration produced was 64 million words of MOS SRAM in 64 banks. For compatibility with existing software written for the Cray-1 and older X-MP models, each EA series CPUs peak performance was 234 MFLOPS
6.
Unix
–
Among these is Apples macOS, which is the Unix version with the largest installed base as of 2014. Many Unix-like operating systems have arisen over the years, of which Linux is the most popular, Unix was originally meant to be a convenient platform for programmers developing software to be run on it and on other systems, rather than for non-programmer users. The system grew larger as the system started spreading in academic circles, as users added their own tools to the system. Unix was designed to be portable, multi-tasking and multi-user in a time-sharing configuration and these concepts are collectively known as the Unix philosophy. By the early 1980s users began seeing Unix as a universal operating system. Under Unix, the system consists of many utilities along with the master control program. To mediate such access, the kernel has special rights, reflected in the division between user space and kernel space, the microkernel concept was introduced in an effort to reverse the trend towards larger kernels and return to a system in which most tasks were completed by smaller utilities. In an era when a standard computer consisted of a disk for storage and a data terminal for input and output. However, modern systems include networking and other new devices, as graphical user interfaces developed, the file model proved inadequate to the task of handling asynchronous events such as those generated by a mouse. In the 1980s, non-blocking I/O and the set of inter-process communication mechanisms were augmented with Unix domain sockets, shared memory, message queues, and semaphores. In microkernel implementations, functions such as network protocols could be moved out of the kernel, Multics introduced many innovations, but had many problems. Frustrated by the size and complexity of Multics but not by the aims and their last researchers to leave Multics, Ken Thompson, Dennis Ritchie, M. D. McIlroy, and J. F. Ossanna, decided to redo the work on a much smaller scale. The name Unics, a pun on Multics, was suggested for the project in 1970. Peter H. Salus credits Peter Neumann with the pun, while Brian Kernighan claims the coining for himself, in 1972, Unix was rewritten in the C programming language. Bell Labs produced several versions of Unix that are referred to as Research Unix. In 1975, the first source license for UNIX was sold to faculty at the University of Illinois Department of Computer Science, UIUC graduate student Greg Chesson was instrumental in negotiating the terms of this license. During the late 1970s and early 1980s, the influence of Unix in academic circles led to adoption of Unix by commercial startups, including Sequent, HP-UX, Solaris, AIX. In the late 1980s, AT&T Unix System Laboratories and Sun Microsystems developed System V Release 4, in the 1990s, Unix-like systems grew in popularity as Linux and BSD distributions were developed through collaboration by a worldwide network of programmers
7.
Cray T3D
–
The T3D was Cray Researchs first attempt at a massively parallel supercomputer architecture. Launched in 1993, it also marked Crays first use of another companys microprocessor, the T3D consisted of between 32 and 2048 Processing Elements, each comprising a 150 MHz DEC Alpha 21064 microprocessor and either 16 or 64 MB of DRAM. PEs were grouped in pairs, or nodes, which incorporated a 6-way processor interconnect switch and these switches had a peak bandwidth of 300 MB/second in each direction and were connected to form a three-dimensional torus network topology. The T3D was designed to be hosted by a Cray Y-MP Model E, M90 or C90-series front-end system and rely on it and its UNICOS operating system for all I/O, the T3D PEs ran a simple microkernel called UNICOS MAX. Several different configurations of T3D were available, the SC models shared a cabinet with a host Y-MP system and were available with either 128 or 256 PEs. The MC models were housed in one or more liquid-cooled cabinet separately from the host, there was also a liquid-cooled MCN model which had an alternative interconnect wiremat allowing non-power-of-2 numbers of PEs. The Cray T3D MC cabinet had an Apple Macintosh PowerBook laptop built into its front and its only purpose was to display animated Cray Research and T3D logos on its color LCD screen. The first T3D delivered was a prototype installed at the Pittsburgh Supercomputing Center in early September 1993, the supercomputer was formally introduced on 27 September 1993. The T3D was superseded in 1995 by the faster and more sophisticated Cray T3E, CRAY T3D System Architecture Overview Manual
8.
Fermilab
–
Fermi National Accelerator Laboratory, located just outside Batavia, Illinois, near Chicago, is a United States Department of Energy national laboratory specializing in high-energy particle physics. Since 2007, Fermilab has been operated by the Fermi Research Alliance, a joint venture of the University of Chicago, Fermilab is a part of the Illinois Technology and Research Corridor. Fermilabs Tevatron was a particle accelerator, at 3.9 miles in circumference, it was the worlds fourth-largest particle accelerator. In 1995, the discovery of the top quark was announced by researchers who used the Tevatrons CDF, in addition to high-energy collider physics, Fermilab hosts fixed-target and neutrino experiments, such as MicroBooNE, NOνA and SeaQuest. Completed neutrino experiments include MINOS, MINOS+, MiniBooNE and SciBooNE, the MiniBooNE detector was a 40-foot diameter sphere containing 800 tons of mineral oil lined with 1,520 phototube detectors. An estimated 1 million neutrino events were recorded each year, SciBooNE sat in the same neutrino beam as MiniBooNE but had fine-grained tracking capabilities. In the public realm, Fermilab hosts many events, not only public science lectures and symposia. The site is open dawn to dusk to visitors who present valid photo identification. Asteroid 11998 Fermilab is named in honor of the laboratory, weston, Illinois, was a community next to Batavia voted out of existence by its village board in 1966 to provide a site for Fermilab. The laboratory was founded in 1967 as the National Accelerator Laboratory, the laboratorys first director was Robert Rathbun Wilson, under whom the laboratory opened ahead of time and under budget. Many of the sculptures on the site are of his creation and he is the namesake of the sites high-rise laboratory building, whose unique shape has become the symbol for Fermilab and which is the center of activity on the campus. After Wilson stepped down in 1978 to protest the lack of funding for the lab and it was under his guidance that the original accelerator was replaced with the Tevatron, an accelerator capable of colliding protons and antiprotons at a combined energy of 1.96 TeV. Lederman stepped down in 1989 and remains Director Emeritus, the science education center at the site was named in his honor. The later directors include, John Peoples,1989 to 1999 Michael S, as of 2014, the first stage in the acceleration process takes place in two ion sources which turn hydrogen gas into H− ions. A magnetron generates a plasma to form the ions near the metal surface, at the exit of RFQ, the beam is matched by medium energy beam transport into the entrance of the linear accelerator. The next stage of acceleration is linear particle accelerator and this stage consists of two segments. The first segment has 5 vacuum vessel for drift tubes, operating at 201 MHz, the second stage has 7 side-coupled cavities, operating at 805 MHz. At the end of linac, the particles are accelerated to 400 MeV, immediately before entering the next accelerator, the H− ions pass through a carbon foil, becoming H+ ions
9.
CERN
–
The European Organization for Nuclear Research, known as CERN, is a European research organization that operates the largest particle physics laboratory in the world. Established in 1954, the organization is based in a northwest suburb of Geneva on the Franco–Swiss border, Israel is the only non-European country granted full membership. The main site at Meyrin hosts a large computing facility, which is used to store and analyse data from experiments. Researchers need remote access to facilities, so the lab has historically been a major wide area network hub. CERN is also the birthplace of the World Wide Web, the convention establishing CERN was ratified on 29 September 1954 by 12 countries in Western Europe. The acronym was retained for the new laboratory after the council was dissolved. CERNs first president was Sir Benjamin Lockspeiser, edoardo Amaldi was the general secretary of CERN at its early stages when operations were still provisional, while the first Director-General was Felix Bloch. The laboratory was originally devoted to the study of atomic nuclei, therefore, the laboratory operated by CERN is commonly referred to as the European laboratory for particle physics, which better describes the research being performed there. Several important achievements in physics have been made through experiments at CERN. The 1984 Nobel Prize for Physics was awarded to Carlo Rubbia, the 1992 Nobel Prize for Physics was awarded to CERN staff researcher Georges Charpak for his invention and development of particle detectors, in particular the multiwire proportional chamber. The World Wide Web began as a CERN project named ENQUIRE, initiated by Tim Berners-Lee in 1989, Berners-Lee and Cailliau were jointly honoured by the Association for Computing Machinery in 1995 for their contributions to the development of the World Wide Web. Based on the concept of hypertext, the project was intended to facilitate the sharing of information between researchers, the first website was activated in 1991. On 30 April 1993, CERN announced that the World Wide Web would be free to anyone, a copy of the original first webpage, created by Berners-Lee, is still published on the World Wide Web Consortiums website as a historical document. Prior to the Webs development, CERN had pioneered the introduction of Internet technology, a short history of this period can be found at CERN. ch. More recently, CERN has become a facility for the development of computing, hosting projects including the Enabling Grids for E-sciencE. It also hosts the CERN Internet Exchange Point, one of the two main internet exchange points in Switzerland. 48×10−5, a measurement with 6. 0-sigma significance. However, on 23 February, CERN stated in a release that the results were flawed due to an incorrectly connected GPS-synchronization cable. In March 2012, the ICARUS Collaboration reported that the measurement would be reproduced by both OPERA and ICARUS, further tests, after fixing the GPS connector, showed speed measurements consistent with the speed of light from four experiments at Gran Sasso, including OPERA
10.
Fortran
–
Fortran is a general-purpose, imperative programming language that is especially suited to numeric computation and scientific computing. It is a language for high-performance computing and is used for programs that benchmark. Fortran encompasses a lineage of versions, each of which evolved to add extensions to the language while usually retaining compatibility with prior versions, the names of earlier versions of the language through FORTRAN77 were conventionally spelled in all-capitals. The capitalization has been dropped in referring to newer versions beginning with Fortran 90, the official language standards now refer to the language as Fortran rather than all-caps FORTRAN. In late 1953, John W. Backus submitted a proposal to his superiors at IBM to develop a practical alternative to assembly language for programming their IBM704 mainframe computer. Backus historic FORTRAN team consisted of programmers Richard Goldberg, Sheldon F. Best, Harlan Herrick, Peter Sheridan, Roy Nutt, Robert Nelson, Irving Ziller, Lois Haibt, and David Sayre. Its concepts included easier entry of equations into a computer, a developed by J. Halcombe Laning and demonstrated in the Laning. A draft specification for The IBM Mathematical Formula Translating System was completed by mid-1954, the first manual for FORTRAN appeared in October 1956, with the first FORTRAN compiler delivered in April 1957. John Backus said during a 1979 interview with Think, the IBM employee magazine, the language was widely adopted by scientists for writing numerically intensive programs, which encouraged compiler writers to produce compilers that could generate faster and more efficient code. The inclusion of a complex data type in the language made Fortran especially suited to technical applications such as electrical engineering. By 1960, versions of FORTRAN were available for the IBM709,650,1620, significantly, the increasing popularity of FORTRAN spurred competing computer manufacturers to provide FORTRAN compilers for their machines, so that by 1963 over 40 FORTRAN compilers existed. For these reasons, FORTRAN is considered to be the first widely used programming language supported across a variety of computer architectures, the arithmetic IF statement was similar to a three-way branch instruction on the IBM704. However, the 704 branch instructions all contained only one destination address, an optimizing compiler like FORTRAN would most likely select the more compact and usually faster Transfers instead of the Compare. Also the Compare considered −0 and +0 to be different values while the Transfer Zero, the FREQUENCY statement in FORTRAN was used originally to give branch probabilities for the three branch cases of the arithmetic IF statement. The Monte Carlo technique is documented in Backus et al, many years later, the FREQUENCY statement had no effect on the code, and was treated as a comment statement, since the compilers no longer did this kind of compile-time simulation. A similar fate has befallen compiler hints in other programming languages. The first FORTRAN compiler reported diagnostic information by halting the program when an error was found and that code could be looked up by the programmer in a error messages table in the operators manual, providing them with a brief description of the problem. Before the development of disk files, text editors and terminals, programs were most often entered on a keyboard onto 80-column punched cards
11.
Bell Labs
–
Nokia Bell Labs is an American research and scientific development company, owned by Finnish company Nokia. Its headquarters are located in Murray Hill, New Jersey, in addition to laboratories around the rest of the United States. The historic laboratory originated in the late 19th century as the Volta Laboratory, Bell Labs was also at one time a division of the American Telephone & Telegraph Company, half-owned through its Western Electric manufacturing subsidiary. Eight Nobel Prizes have been awarded for work completed at Bell Laboratories, in 1880, the French government awarded Alexander Graham Bell the Volta Prize of 50,000 francs, approximately US$10,000 at that time for the invention of the telephone. Bell used the award to fund the Volta Laboratory in Washington, D. C. in collaboration with Sumner Tainter, the laboratory is also variously known as the Volta Bureau, the Bell Carriage House, the Bell Laboratory and the Volta Laboratory. The laboratory focused on the analysis, recording, and transmission of sound, Bell used his considerable profits from the laboratory for further research and education to permit the diffusion of knowledge relating to the deaf. This resulted in the founding of the Volta Bureau c,1887, located at Bells fathers house at 1527 35th Street in Washington, D. C. where its carriage house became their headquarters in 1889. In 1893, Bell constructed a new building, close by at 1537 35th St. specifically to house the lab, the building was declared a National Historic Landmark in 1972. In 1884, the American Bell Telephone Company created the Mechanical Department from the Electrical, the first president of research was Frank B. Jewett, who stayed there until 1940, ownership of Bell Laboratories was evenly split between AT&T and the Western Electric Company. Its principal work was to plan, design, and support the equipment that Western Electric built for Bell System operating companies and this included everything from telephones, telephone exchange switches, and transmission equipment. Bell Labs also carried out consulting work for the Bell Telephone Company, a few workers were assigned to basic research, and this attracted much attention, especially since they produced several Nobel Prize winners. Until the 1940s, the principal locations were in and around the Bell Labs Building in New York City. Of these, Murray Hill and Crawford Hill remain in existence, the largest grouping of people in the company was in Illinois, at Naperville-Lisle, in the Chicago area, which had the largest concentration of employees prior to 2001. Since 2001, many of the locations have been scaled down or closed. The Holmdel site, a 1.9 million square foot structure set on 473 acres, was closed in 2007, the mirrored-glass building was designed by Eero Saarinen. In August 2013, Somerset Development bought the building, intending to redevelop it into a commercial and residential project. The prospects of success are clouded by the difficulty of readapting Saarinens design and by the current glut of aging, eight Nobel Prizes have been awarded for work completed at Bell Laboratories
12.
Linux kernel
–
The Linux kernel is a monolithic Unix-like computer operating system kernel. The Android operating system for computers, smartphones and smartwatches is also based atop the Linux kernel. While the adoption on desktop computers is low, Linux-based operating systems dominate nearly every segment of computing. As of November 2016, all but two of the worlds 500 most powerful supercomputers run Linux, Linux rapidly attracted developers and users who adopted it as the kernel for other free software projects, notably the GNU Operating System. The Linux kernel has received contributions from nearly 12,000 programmers from more than 1,200 companies, the Linux kernel API, the application programming interface through which user programs interact with the kernel, is meant to be very stable and to not break userspace programs. As part of the functionality, device drivers control the hardware. However, the interface between the kernel and loadable kernel modules, unlike in many other kernels and operating systems, is not meant to be stable by design. The Linux kernel, developed by contributors worldwide, is a prominent example of free, day-to-day development discussions take place on the Linux kernel mailing list. The Linux kernel is released under the GNU General Public License version 2, in April 1991, Linus Torvalds, at the time a 21-year-old computer science student at the University of Helsinki, Finland, started working on some simple ideas for an operating system. He started with a task switcher in Intel 80386 assembly language, on 25 August 1991, Torvalds posted the following to comp. os. minix, a newsgroup on Usenet, Im doing a operating system for 386 AT clones. This has been brewing since April, and is starting to get ready, id like any feedback on things people like/dislike in minix, as my OS resembles it somewhat. Ive currently ported bash and gcc, and things seem to work and this implies that Ill get something practical within a few months Yes - its free of any minix code, and it has a multi-threaded fs. It is NOT portable, and it never will support anything other than AT-harddisks, as thats all I have. Its mostly in C, but most people wouldnt call what I write C and it uses every conceivable feature of the 386 I could find, as it was also a project to teach me about the 386. As already mentioned, it uses a MMU, for both paging and segmentation and its the segmentation that makes it REALLY386 dependent. Some of my C-files are almost as much assembler as C, unlike minix, I also happen to LIKE interrupts, so interrupts are handled without trying to hide the reason behind them. After that, many people contributed code to the project, early on, the MINIX community contributed code and ideas to the Linux kernel. At the time, the GNU Project had created many of the components required for an operating system
