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36-559: The X1 was designed by the Mathematical Centre in Amsterdam , an academic organization that had been involved in computer design since 1947, and manufactured by Electrologica NV, a company formed expressly for the purpose of producing the machine. The X1 was a solid-state binary computer ("completely transistorized") with magnetic core memory . Word-length was 27 bits and peripherals included punched and magnetic tape. It

72-658: A CWI spinoff . Work at the institute was recognized by national or international research awards, such as the Lanchester Prize (awarded yearly by INFORMS ), the Gödel Prize (awarded by ACM SIGACT ) and the Spinoza Prize . Most of its senior researchers hold part-time professorships at other Dutch universities, with the institute producing over 170 full professors during the course of its history. Several CWI researchers have been recognized as members of

108-488: A longer fatigue life, improved aerodynamics, and a lighter structure; Fokker became the first such company after de Havilland to employ such means. In 1953, the proposed airliner received the name Friendship . A total of four prototypes were produced, two of these being flyable aircraft that were used for the test flight programme and were paid for by the Netherlands Institute of Aircraft Development ;

144-654: A mixture of ATR 42 and ATR 72 aircraft by the end of 2009, the last of these aircraft were subsequently donated to the Hickory Aviation Museum . As of July 2010 a total of 65 F27s were in commercial service with almost 30 different airlines. By July 2013, only 25 Friendships remained in service, operated by 13 different airlines; most of these were F27-500s, with two -400s and a solitary -600 series aircraft in service. Italian cargo airline MiniLiner operated six F27s and Air Panama had four in its fleet. The United States Army Parachute Team has operated

180-442: A simple assembler in its read-only memory . It has rather basic features: symbolic addresses may be defined, but symbols are only two letters long. Instructions are named by a combination of a digit representing the operation, and a letter designating the register to be operated on, or one or two letters indicating an operation class. For example, "0A" means "add memory content to accumulator A", and "5P" means "set an accumulator to

216-588: Is a turboprop airliner developed and manufactured by the Dutch aircraft manufacturer Fokker . It is the most numerous post-war aircraft manufactured in the Netherlands; the F27 was also one of the most successful European airliners of its era. The F27 was developed during the early 1950s with the intent of producing a capable successor to the earlier piston engine -powered airliners that had become commonplace on

252-406: Is a peculiarity of the assembler; the hardware addressing simply uses 15 bit addresses. Centrum Wiskunde %26 Informatica The Centrum Wiskunde & Informatica (abbr. CWI ; English: "National Research Institute for Mathematics and Computer Science") is a research centre in the field of mathematics and theoretical computer science . It is part of the institutes organization of

288-724: Is the case in most computers. A similar capability existed in the Zuse Z22 and the ZEBRA , and much later in the ARM architecture . The approach used in the X1 is more flexible than these others: it makes execution conditional on the current state of the condition flag that is set by a previous instruction if it includes a modifier for that purpose, but untouched otherwise. As a result, conditional execution can be based on tests made some number of lines earlier, rather than being conditional only based on

324-680: The Dutch Research Council (NWO) and is located at the Amsterdam Science Park . This institute is famous as the creation site of the programming language Python . It was a founding member of the European Research Consortium for Informatics and Mathematics (ERCIM). The institute was founded in 1946 by Johannes van der Corput , David van Dantzig , Jurjen Koksma , Hendrik Anthony Kramers , Marcel Minnaert and Jan Arnoldus Schouten . It

360-778: The Royal Netherlands Academy of Arts and Sciences , the Academia Europaea , or as knights in the Order of the Netherlands Lion . In February 2017, CWI in association with Google announced a successful collision attack on SHA 1 encryption algorithm. CWI was an early user of the Internet in Europe, in the form of a TCP/IP connection to NSFNET . Piet Beertema at CWI established one of

396-512: The DC-3, the F27 possessed superior levels of efficiency, enabling faster flight times, greater passenger comfort and a higher level of reliability. In 1960, the base purchase price for an RDa.6-powered F27 was £239,000. By the end of the production run for the Fokker F27 in 1987, a total of 592 units had been completed by Fokker (additionally, another 207 F-27s and FH-227s had been produced in

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432-477: The F27 made its maiden flight ; on 19 November 1958, the type was introduced to revenue service. Shortly after its introduction, the F27 was recognised as being a commercial success. Under a licensing arrangement reached between Fokker and the U.S. aircraft manufacturer Fairchild , the F27 was manufactured in the United States by the latter; Fairchild went on to independently develop a stretched version of

468-487: The F27 were developed and made available for commercial operators. Several military transport models were also produced. Fokker also chose to design a dedicated model of the F27 for conducting maritime reconnaissance missions. During 1952, Fokker established a relationship with the US aircraft manufacturer Fairchild , which was interested in the upcoming F27. In 1956, Fokker signed a licensing deal with Fairchild, under which

504-576: The F27. The Fokker 50 ultimately replaced the F27 in production. In November 1958, the first production aircraft, an F27-100 model, was delivered to Irish airline Aer Lingus ; it performed its first revenue flight in the following month. Other early customers of the Friendship included Braathens SAFE and Luxair in Europe; New Zealand National Airways Corporation ; Trans Australia Airlines and its Australian competitors Ansett and East-West Airlines ; and Turkish Airlines . Initial sales for

540-423: The US by Fairchild), more than any other western European civil turboprop airliner at the time. In later service, many aircraft have been modified from their original configurations for passenger service to perform cargo or express-package freighter duties instead. The last major cargo user of the F27 in the United States was FedEx Express , using it as a cargo "feeder" aircraft. These were retired and replaced by

576-602: The airliner, which was designated as the Fairchild FH-227 . During the 1980s, Fokker developed a modernised successor to the F27, the Fokker 50 , which eventually replaced it in production. In the aftermath of the Second World War , twin-engine all-metal monoplanes such as the successful Douglas DC-3 airliner dominated commuter aviation. Over 10,000 DC-3s had been manufactured during wartime, which led to

612-460: The design team chose to incorporate various new technologies into the tentative design. Fokker evaluated several potential configurations for the airliner, including the use of Wright Cyclone radial engines , before finally settling upon a high- wing aircraft, which was furnished with a pair of Rolls-Royce Dart turboprop engines and a pressurised cabin which contained a total of 28 passengers. The Dart engine had already proven successful on

648-690: The development of scheduling algorithms for the Dutch railway system (the Nederlandse Spoorwegen , one of the busiest rail networks in the world) and the development of the Python programming language by Guido van Rossum . Python has played an important role in the development of the Google search platform from the beginning, and it continues to do so as the system grows and evolves. Many information retrieval techniques used by packages such as SPSS were initially developed by Data Distilleries,

684-633: The early 1980s, Fokker decided to develop a modernised successor to the F27 Friendship, designated as the F27 Mark 050 and marketed as the Fokker 50 . Although originating from the F27-500 airframe, the Fokker 50 was virtually a new aircraft, complete with Pratt & Whitney Canada engines and modern systems, which led to its general performance and passenger comfort being noticeably improved over

720-481: The early models of the Vickers Viscount , while a high-mounted wing had been selected as it produced a higher lift coefficient than a lower counterpart, it also enabled easier ground loading due to a lower floor level and provided unfettered external views to passengers without any weight increase. In the aircraft's construction, Fokker used an innovative metal-to-metal bonding technique, Redux , resulting in

756-559: The first two connections outside the United States to the NSFNET (shortly after France's INRIA ) for EUnet on 17 November 1988. The first Dutch country code top-level domain issued was cwi.nl. When this domain cwi.nl was registered, on 1 May 1986, .nl effectively became the first active ccTLD outside the United States . For the first ten years CWI, or rather Beertema, managed the .nl administration, until in 1996 this task

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792-482: The founder of computer science (or informatica ) in the Netherlands, was the director of the institute for almost 20 years. Edsger Dijkstra did most of his early influential work on algorithms and formal methods at CWI. The first Dutch computers, the Electrologica X1 and Electrologica X8 , were both designed at the centre, and Electrologica was created as a spinoff to manufacture the machines. In 1983,

828-577: The latter was authorised to manufacture the F27 in the USA. On 12 April 1958, the first American-built aircraft conducted its first flight. Production of Fairchild built aircraft would continue until July 1973. Fairchild proceeded to independently develop a stretched version of the airliner, designated as the FH-227 . The majority of sales completed by Fairchild fell within the North American market. In

864-529: The market, such as the Douglas DC-3 . A key innovation of the F27 was the adoption of the Rolls-Royce Dart turboprop engine, which produced substantially less vibration and noise which provided improved conditions for passengers; another major comfort feature was cabin pressurisation . Innovative manufacturing techniques were also employed in the aircraft's construction. On 24 November 1955,

900-490: The maximum number of passengers which could be carried to 32. These aircraft were also powered by the Dart Mk 528 engine, which was capable of generating greater thrust. Throughout the F27's production life, Fokker proceeded to adapt the design for various purposes and roles. Via modifications such as the adoption of improved engines, rearranged loading doors, elongated fuselages, and other changes, several different models of

936-426: The name of the institute was changed to Centrum Wiskunde & Informatica (CWI) to reflect a governmental push for emphasizing computer science research in the Netherlands. The institute is known for its work in fields such as operations research , software engineering , information processing, and mathematical applications in life sciences and logistics . More recent examples of research results from CWI include

972-425: The negative of another accumulator". The normal use of symbolic addresses is to name "paragraphs", i.e., related blocks of code or data. The symbolic addresses would be modified by a "line number" (a numeric offset) and a "page number" (a number in the range 0 to 31). For example, "3 FE 6" is line number 3, page number 6, representing an offset of 195 (6 * 32 + 3) from the start of paragraph FE. This address notation

1008-416: The other two prototypes were for static and fatigue testing. On 24 November 1955, the first prototype, registered PH-NIV , performed its maiden flight . The second prototype and initial production machines were 0.9 m (3 ft) longer than the first prototype in order to address a revealed tendency for slightly tail-heavy handling as well as to provide additional space for four more passengers, raising

1044-428: The result of the most recent arithmetic operation. This allowed for compact expression of programs. The following example demonstrates the loading of the value of memory at n into the accumulator A , calling a subroutine (which presumably uses that value in A ), and finally setting A to be the absolute value of the number read: The X1 arithmetic operators used binary ones' complement arithmetic. The X1 included

1080-402: The type being highly available and thus encouraging its adoption by hundreds of operators across the world. By the early 1950s, various aircraft manufacturers had begun considering the post-war requirements of the civil aviation market and several commenced work upon projects aiming to produce designs for new aircraft which would be viewed as best meeting these requirements; Dutch firm Fokker

1116-453: The type were slow, which led to Fokker seeking financial support from banks and from the Dutch government in order to maintain production of the airliner while more customers were sought. In 1960, demand for the F27 increased rapidly as multiple airlines placed sizable orders for the type. This is in part due to the spreading reputation of the type, having been found by operators that, in comparison to its piston-engine wartime counterparts like

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1152-513: The work of its researchers at the disposal of society, mainly by collaborating with commercial companies and creating spin-off businesses. In 2000 CWI established "CWI Incubator BV", a dedicated company with the aim to generate high tech spin-off companies. Some of the CWI spinoffs include: 52°21′23″N 4°57′07″E  /  52.35639°N 4.95194°E  / 52.35639; 4.95194 Fokker F27 Friendship The Fokker F27 Friendship

1188-418: Was amongst the companies pursuing development of such an aircraft. By 1951, figures within Fokker were urging that design work be undertaken on a prospective 32-seat airliner intended as a direct replacement for the popular DC-3. Fokker sought the opinions of existing DC-3 operators on what performance increases and refinements they would expect of a new model of commuter aircraft. On the basis of this feedback,

1224-482: Was one of the first European computers to have an interrupt facility. The X1 was the subject of Edsger Dijkstra's Ph.D. dissertation, and the target of the first complete working ALGOL 60 compiler, completed by Dijkstra and Jaap Zonneveld. In 1965, the X1 was superseded by the X8 . Electrologica was taken over by Philips a few years later. The X1 allowed conditional execution of every instruction, not just branches as

1260-794: Was originally called Mathematical Centre (in Dutch: Mathematisch Centrum ). One early mission was to develop mathematical prediction models to assist large Dutch engineering projects, such as the Delta Works . During this early period, the Mathematics Institute also helped with designing the wings of the Fokker F27 Friendship airplane, voted in 2006 as the most beautiful Dutch design of the 20th century. The computer science component developed soon after. Adriaan van Wijngaarden , considered

1296-459: Was transferred to its spin-off SIDN. The Amsterdam Internet Exchange (one of the largest Internet Exchanges in the world, in terms of both members and throughput traffic) is located at the neighbouring SARA (an early CWI spin-off) and Nikhef institutes. The World Wide Web Consortium (W3C) office for the Benelux countries is located at CWI. CWI has demonstrated a continuing effort to put

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