A Colossus Mark II computer. The slanted control panel on the left was used to set the pin patterns on the Lorenz; the paper tape transport is on the right.

The Colossus machines were electronic computing devices used by British codebreakers to read encrypted German messages during World War II. Electronics refers to the flow of charge (moving Electrons through Nonmetal conductors (mainly Semiconductors, whereas electrical Computing is usually defined like the activity of using and developing Computer technology Computer hardware and software. Cryptanalysis (from the Greek kryptós, "hidden" and analýein, "to loosen" or "to untie" is the study of methods for Nazi Germany and the Third Reich are the common English names for Germany under the regime of Adolf Hitler and the National Socialist German Workers World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including These were the world's first programmable, digital, electronic, computing devices. They used vacuum tubes (thermionic valves) to perform the calculations. This article is about the electronic device not an evacuated pipe used for experiments in Free-fall.

Colossus was designed by engineer Tommy Flowers at the Post Office Research Station, Dollis Hill with input from mathematician Max Newman and group at Bletchley Park. Thomas (Tommy Harold Flowers MBE ( 22 December 1905 &ndash 28 October 1998) was an English engineer The Post Office Research Station at Dollis Hill, London, was first established in 1921 and opened by the Prime Minister Ramsay MacDonald in 1933 Dollis Hill is an area of north-west London. It lies close to Willesden, in the London Borough of Brent. Maxwell Herman Alexander Newman ( February 7 1897 &ndash February 22 1984) was a British Mathematician and Codebreaker Bletchley Park, also known as Station X, is an estate located in the town of Bletchley, in Buckinghamshire, and (since 1967 part of Milton Keynes The prototype, Colossus Mark I, was shown to be working in December 1943 and was operational at Bletchley Park by February 1944. An improved Colossus Mark II was first installed in June 1944, with input from Allen Coombs, and ten Colossi had been constructed by the end of the war. Allen William Mark (Doc Coombs ( 23 October 1911 &ndash 30 January 1995) was a British electronics engineer at the Post Office Research

The Colossus computers were used to help decipher teleprinter messages which had been encrypted using the Lorenz SZ40/42 machine — British codebreakers referred to encrypted German teleprinter traffic as "Fish" and called the SZ40/42 machine and its traffic as "Tunny". A computer is a Machine that manipulates data according to a list of instructions. A teleprinter ( "Tunny" redirects here For the fish see Tuna. The Lorenz SZ 40 and SZ 42 ( Schlüsselzusatz, meaning For the (Fibonacci Shrinking Stream cipher published in 1993, see FISH (cipher. "Tunny" redirects here For the fish see Tuna. The Lorenz SZ 40 and SZ 42 ( Schlüsselzusatz, meaning Colossus compared two data streams, counting each match based on a programmable boolean function. In Mathematics, a (finitary Boolean function is a function of the form f: B k &rarr B, where B  = {0 1} The encrypted message was read at high speed from a paper tape. The other stream was generated internally, and was an electronic simulation of the Lorenz machine at various trial settings. If the match count for a setting was above a certain threshold, it would be output on an electric typewriter.

## Purpose and origins

The Lorenz machine was used by the Germans to encrypt high-level teleprinter communications. It contained 12 wheels with a total of 501 pins.

The Colossus computers were used in the cryptanalysis of high-level German communications, messages which had been encrypted using the Lorenz SZ 40/42 cipher machine; part of the operation of Colossus was to emulate the mechanical Lorenz machine electronically. Cryptanalysis (from the Greek kryptós, "hidden" and analýein, "to loosen" or "to untie" is the study of methods for "Tunny" redirects here For the fish see Tuna. The Lorenz SZ 40 and SZ 42 ( Schlüsselzusatz, meaning To encrypt a message with the Lorenz machine, the plaintext was combined with a stream of key bits, grouped in fives. In Cryptography, plaintext is the information which the sender wishes to transmit to the receiver(s A bit is a binary digit, taking a value of either 0 or 1 Binary digits are a basic unit of Information storage and communication The keystream was generated using twelve pinwheels: five were termed (by the British) $\chi\,$ ("chi") wheels, another five $\psi\,$ ("psi") wheels, and the remaining two the "motor wheels". In Cryptography, a keystream is a stream of random or pseudorandom characters that are combined with a Plaintext message to produce In Cryptography, a pinwheel was a device for producing a short pseudorandom sequence of Bits (determined by the machine's initial settings as a component Chi ( Uppercase Χ, Lowercase χ; Χι He is the 22nd letter of the Greek alphabet, pronounced as in English For other uses see Psi. Psi (uppercase Ψ, lowercase ψ) is the 23rd letter of the Greek alphabet and has a The $\chi\,$ wheels stepped regularly with each letter that was encrypted, while the $\psi\,$ wheels stepped irregularly, controlled by the motor wheels.

Bill Tutte, a cryptanalyst at Bletchley Park, discovered that the keystream produced by the machine exhibited statistical biases deviating from random, and that these biases could be used to break the cipher and read messages. William Thomas Tutte ( May 14 1917 &ndash May 2 2002) was a British, later Canadian codebreaker Bletchley Park, also known as Station X, is an estate located in the town of Bletchley, in Buckinghamshire, and (since 1967 part of Milton Keynes In order to read messages, there were two tasks that needed to be performed. The first task was wheel breaking, which was discovering the pin patterns for all the wheels. These patterns were set up once on the Lorenz machine and then used for a fixed period of time and for a number of different messages. The second task was wheel setting, which could be attempted once the pin patterns were known. Each message encrypted using Lorenz was enciphered at a different start position for the wheels. The process of wheel setting found the start position for a message. Initially Colossus was used to help with wheel setting, but later it was found it could also be adapted to the process of wheel breaking as well.

Colossus was operated in the Newmanry, the section at Bletchley Park responsible for machine methods against the Lorenz machine, headed by the mathematician Max Newman. The Newmanry was a section at Bletchley Park, the British Codebreaking station during World War II. Maxwell Herman Alexander Newman ( February 7 1897 &ndash February 22 1984) was a British Mathematician and Codebreaker

Colossus was developed out of a prior project which produced a special purpose opto-mechanical comparator machine called "Heath Robinson". Heath Robinson was a machine used by British Codebreakers at Bletchley Park during World War II to solve messages in a German Teleprinter cipher The main problem with Robinson was synchronising two paper tapes, one punched with the enciphered message, the other representing the patterns produced by the wheels of the Lorenz machine, that tended to stretch when being read at over 1000 characters per second, resulting in unreliable counts. Punched tape or paper tape is a largely obsolete form of Data storage, consisting of a long strip of paper in which holes are punched to store data Colossus solved this problem by reproducing one of the tapes electronically. The remaining single tape could be fed through Colossus at a higher speed and could be counted much more reliably.

## The construction of Colossus

Tommy Flowers spent eleven months (early February 1943 to early January 1944) designing and building Colossus at the Post Office Research Station, Dollis Hill, in northwest London. Thomas (Tommy Harold Flowers MBE ( 22 December 1905 &ndash 28 October 1998) was an English engineer The Post Office Research Station at Dollis Hill, London, was first established in 1921 and opened by the Prime Minister Ramsay MacDonald in 1933 Dollis Hill is an area of north-west London. It lies close to Willesden, in the London Borough of Brent. After a functional test in December 1943, Colossus was dismantled and shipped north to Bletchley Park, where it was delivered on 18 January 1944, and attacked its first message on 5 February. Year 1943 ( MCMXLIII) was a Common year starting on Friday (the link will display full 1943 calendar of the Gregorian calendar. Events 350 - Generallus Magnentius deposes Roman Emperor Constans and proclaims himself Emperor Year 1944 ( MCMXLIV) was a Leap year starting on Saturday (link will display full calendar of the Gregorian calendar. Events 1576 - Henry of Navarre converts to Roman Catholicism in order to ensure his right to the throne of France. [1]

The Mark I was followed by nine Mark 2 Colossus machines, the first being installed in June 1944, and the original Mark I machine was converted into a Mark 2. An eleventh Colossus was essentially finished at the end of the war. Colossus Mark 1 contained 1,500 electronic valves (tubes). Colossus Mark 2 with 2,400 valves was both 5 times faster and simpler to operate than Mark 1, greatly speeding the decoding process. Mark 2 was designed while Mark 1 was being constructed. Allen Coombs took over leadership of the Colossus Mark 2 project when Tommy Flowers moved on to other projects. Allen William Mark (Doc Coombs ( 23 October 1911 &ndash 30 January 1995) was a British electronics engineer at the Post Office Research Thomas (Tommy Harold Flowers MBE ( 22 December 1905 &ndash 28 October 1998) was an English engineer For comparison, later stored-program computers like the Manchester Mark I of 1949 used about 4,200 valves. This article is about the early British computer. The term "Manchester Mark I" can also refer to the Avro Manchester heavy bomber in RAF service during Year 1949 ( MCMXLIX) was a Common year starting on Saturday (link will display the full calendar of the Gregorian calendar. In comparison, ENIAC (1946) used 17,468 valves, but was not a software programmable machine. ENIAC, short for Electronic Numerical Integrator And Computer, was the first general-purpose electronic Computer. Year 1946 ( MCMXLVI) was a Common year starting on Tuesday (link will display full 1946 calendar of the Gregorian calendar.

Colossus dispensed with the second tape of the Heath Robinson design by generating the wheel patterns electronically, and processing 5,000 characters per second with the paper tape moving at 40 ft/s (12 m/s or 30 mph). The circuits were synchronized by a clock signal generated by the punched tape. In Electronics and especially synchronous Digital circuits a clock signal is a signal used to coordinate the actions of two or more circuits The speed of calculation was thus limited by the mechanics of the tape reader. Tommy Flowers tested the tape reader up to 9,700 characters per second (60 mph) before the tape disintegrated. He settled on 5,000 characters/second as the desirable speed for regular operation. Sometimes, two or more Colossus computers tried different possibilities simultaneously in what now is called parallel computing, greatly speeding the decoding process. Parallel computing is a form of computation in which many instructions are carried out simultaneously operating on the principle that large problems can often

Colossus included the first ever use of shift registers and systolic arrays, enabling five simultaneous tests, each involving up to 100 Boolean calculations, on each of the five channels on the punched tape (although in normal operation only one or two channels were examined in any run). In Digital circuits a shift register is a group of flip flops set up in a linear fashion which have their inputs and outputs connected together in such a way that the In Computer architecture, a systolic array is a pipe network arrangement of processing units called cells Boolean algebra (or Boolean logic) is a logical calculus of truth values, developed by George Boole in the late 1830s

Initially Colossus was only used to determine the initial wheel positions used for a particular message (termed wheel setting). The Mark 2 included mechanisms intended to help determine pin patterns (wheel breaking). Both models were programmable using switches and plug panels in a way the Robinsons had not been.

## Design and operation

In 1994, a team led by Tony Sale began a reconstruction of a Colossus at Bletchley Park. Here, in 2006, Sale supervises the breaking of an enciphered message with the completed machine.

Colossus used state-of-the-art vacuum tubes (thermionic valves), thyratrons and photomultipliers to optically read a paper tape and then applied a programmable logical function to every character, counting how often this function returned "true". This article is about the electronic device not an evacuated pipe used for experiments in Free-fall. This article is about the electronic device not an evacuated pipe used for experiments in Free-fall. A thyratron is a type of Gas filled tube used as a high Energy electrical Switch and controlled Rectifier. Photomultiplier tubes ( photomultipliers or PMT s for short members of the class of Vacuum tubes and more specifically Phototubes are extremely Although machines with many valves were known to have high failure rates, it was recognised that valve failures occurred most frequently with the current surge at power on, so the Colossus machines, once turned on, were never powered down unless they malfunctioned.

Colossus was the first of the electronic digital machines with programmability, albeit limited in modern terms. It was not, however, a fully general Turing-complete computer, even though Alan Turing worked at Bletchley Park. In computability theory, several closely-related terms are used to describe the "computational power" of a computational system (such as an Abstract machine or Alan Mathison Turing, OBE, FRS (ˈt(jʊ(ərɪŋ (23 June 1912 &ndash 7 June 1954 was an English Mathematician Bletchley Park, also known as Station X, is an estate located in the town of Bletchley, in Buckinghamshire, and (since 1967 part of Milton Keynes It was not then realized that Turing completeness was significant; most of the other pioneering modern computing machines were also not Turing complete (e. g. the Atanasoff–Berry Computer, the Harvard Mark I electro-mechanical relay machine, the Bell Labs relay machines (by George Stibitz et al), or the first designs of Konrad Zuse). The Atanasoff–Berry Computer ( ABC) was the first electronic Digital Computing device The IBM Automatic Sequence Controlled Calculator ( ASCC) called the Mark I by Harvard University, was the first large-scale automatic digital Bell Laboratories (also known as Bell Labs and formerly known as AT&T Bell Laboratories and Bell Telephone Laboratories) is the Research organization George Robert Stibitz ( April 20, 1904 &ndash January 31, 1995) is internationally recognized as a father of the modern digital computer Konrad Zuse (ˈkɔnʁat ˈtsuːzə June 22, 1910 Berlin - December 18, 1995 Hünfeld) was a German The notion of a computer as a general purpose machine--that is, as more than a calculator devoted to solving difficult but specific problems--would not become prominent for several years. A calculator is device for performing mathematical calculations distinguished from a Computer by having a limited problem solving ability and an interface optimized for interactive

Colossus was preceded by several computers, many of them first in some category. Zuse's Z3 was the first functional fully program-controlled computer, and was based on electromechanical relays, as were the (less advanced) Bell Labs machines of the late 1930s (George Stibitz, et al). Konrad Zuse (ˈkɔnʁat ˈtsuːzə June 22, 1910 Berlin - December 18, 1995 Hünfeld) was a German Konrad Zuse 's A computer is a Machine that manipulates data according to a list of instructions. Bell Laboratories (also known as Bell Labs and formerly known as AT&T Bell Laboratories and Bell Telephone Laboratories) is the Research organization George Robert Stibitz ( April 20, 1904 &ndash January 31, 1995) is internationally recognized as a father of the modern digital computer The Atanasoff–Berry Computer was electronic and binary (digital) but not programmable. The Atanasoff–Berry Computer ( ABC) was the first electronic Digital Computing device Assorted analog computers were semiprogrammable; some of these much predated the 1930s (e. An analog computer (spelt analogue in British English is a form of Computer that uses continuous physical phenomena such as electrical mechanical g. , Vannevar Bush). Vannevar Bush ( March 11, 1890 &ndash June 30, 1974; pronounced "VAN-ee-var" ˈvæˌniː Babbage's Analytical engine predated all these (in the mid-1800s), and was both digital and programmable though entirely mechanical, but was only partially constructed and never functioned during Babbage's life (a replica of his Difference engine No. 2, built in 1991, does work, however). The analytical engine, an important step in the History of computers, was the design of a mechanical general-purpose Computer by the British mathematician Charles The Difference Engine was an automatic mechanical calculator designed to tabulate polynomial functions. Colossus was the first combining digital, (partially) programmable, and electronic. The first fully programmable digital electronic computer was the 1948 Manchester Small Scale Experimental Machine. The Manchester Small-Scale Experimental Machine (SSEM, nicknamed Baby, was the world's first stored-program Computer.

Defining characteristics of some early digital computers of the 1940s (See History of computing hardware)
NameFirst operationalNumeral systemComputing mechanismProgrammingTuring complete
Zuse Z3 (Germany)May 1941BinaryElectro-mechanicalProgram-controlled by punched film stockYes (1998)
Atanasoff–Berry Computer (USA)Summer 1941BinaryElectronicNot programmable—single purposeNo
Colossus (UK)December 1943BinaryElectronicProgram-controlled by patch cables and switchesNo
Harvard Mark I – IBM ASCC (USA)1944DecimalElectro-mechanicalProgram-controlled by 24-channel punched paper tape (but no conditional branch)Yes (1998)
ENIAC (USA)November 1945DecimalElectronicProgram-controlled by patch cables and switchesYes
Manchester Small-Scale Experimental Machine (UK)June 1948BinaryElectronicStored-program in Williams cathode ray tube memoryYes
Modified ENIAC (USA)September 1948DecimalElectronicProgram-controlled by patch cables and switches plus a primitive read-only stored programming mechanism using the Function Tables as program ROMYes
EDSAC (UK)May 1949BinaryElectronicStored-program in mercury delay line memoryYes
Manchester Mark I (UK)October 1949BinaryElectronicWilliams cathode ray tube memory and magnetic drum memoryYes
CSIRAC (Australia)November 1949BinaryElectronicStored-program in mercury delay line memoryYes

## Influence and fate

The use to which the Colossi were put was of the highest secrecy, and the Colossus itself was highly secret, and remained so for many years after the War. The history of computer hardware encompasses the hardware, its architecture, and its impact on software. Computer programs (also software programs, or just programs) are instructions for a Computer. In computability theory, several closely-related terms are used to describe the "computational power" of a computational system (such as an Abstract machine or Konrad Zuse (ˈkɔnʁat ˈtsuːzə June 22, 1910 Berlin - December 18, 1995 Hünfeld) was a German Konrad Zuse 's Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. In Engineering, electromechanics combines the Sciences of Electromagnetism of Electrical engineering and mechanics. This focuses on Motion picture film For Still photography film see Photographic film. Konrad Zuse 's The Atanasoff–Berry Computer ( ABC) was the first electronic Digital Computing device The United States of America —commonly referred to as the The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located The IBM Automatic Sequence Controlled Calculator ( ASCC) called the Mark I by Harvard University, was the first large-scale automatic digital The United States of America —commonly referred to as the The decimal ( base ten or occasionally denary) Numeral system has ten as its base. In Engineering, electromechanics combines the Sciences of Electromagnetism of Electrical engineering and mechanics. Punched tape or paper tape is a largely obsolete form of Data storage, consisting of a long strip of paper in which holes are punched to store data Konrad Zuse 's ENIAC, short for Electronic Numerical Integrator And Computer, was the first general-purpose electronic Computer. The United States of America —commonly referred to as the The decimal ( base ten or occasionally denary) Numeral system has ten as its base. The Manchester Small-Scale Experimental Machine (SSEM, nicknamed Baby, was the world's first stored-program Computer. The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located The von Neumann architecture is a design model for a stored-program Digital computer that uses a processing unit and a single separate storage structure The Williams tube or the Williams-Kilburn tube (after inventors Freddie Williams and Tom Kilburn) developed about 1946 or 1947 ENIAC, short for Electronic Numerical Integrator And Computer, was the first general-purpose electronic Computer. The United States of America —commonly referred to as the The decimal ( base ten or occasionally denary) Numeral system has ten as its base. Electronic Delay Storage Automatic Calculator ( EDSAC) was an early British Computer. The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located The von Neumann architecture is a design model for a stored-program Digital computer that uses a processing unit and a single separate storage structure Genesis in radar The basic concept of the delay line originated with World War II Radar research as a system to reduce clutter from reflections from the ground This article is about the early British computer. The term "Manchester Mark I" can also refer to the Avro Manchester heavy bomber in RAF service during The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located The Williams tube or the Williams-Kilburn tube (after inventors Freddie Williams and Tom Kilburn) developed about 1946 or 1947 Drum memory is a magnetic Data storage device and was an early form of Computer memory widely used in the 1950s and into the 1960s invented by Gustav Tauschek CSIRAC ( C ouncil for S cientific and I ndustrial R esearch A utomatic C omputer, pronounced /'sаɪræk/ For a topic outline on this subject see List of basic Australia topics. The von Neumann architecture is a design model for a stored-program Digital computer that uses a processing unit and a single separate storage structure Genesis in radar The basic concept of the delay line originated with World War II Radar research as a system to reduce clutter from reflections from the ground Thus, Colossus could not be included in the history of computing hardware for many years, and Flowers and his associates also were deprived of the recognition they were due. The history of computer hardware encompasses the hardware, its architecture, and its impact on software.

Being not widely known, it therefore had little direct influence on the development of later computers; EDVAC was the early design which had the most influence on subsequent computer architecture. EDVAC ( E lectronic D iscrete V ariable A utomatic C omputer) was one of the earliest electronic Computers

However, the technology of Colossus, and the knowledge that reliable high-speed electronic digital computing devices were feasible, had a significant influence on the development of early computers in Britain and probably in the US. A number of people who were associated with the project and knew all about Colossus played significant roles in early computer work in Britain. In 1972, Herman Goldstine wrote that:

"Britain had such vitality that it could immediately after the war embark on so many well-conceived and well-executed projects in the computer field". Year 1972 ( MCMLXXII) was a Leap year starting on Saturday (link will display full calendar of the Gregorian calendar. Herman Heine Goldstine ( September 13, 1913 &ndash June 16, 2004) Mathematician, Computer scientist and Scientific [2]

In writing that, Goldstine was unaware of Colossus, and its legacy to those projects of people such as Alan Turing (with the Pilot ACE and ACE), and Max Newman and I. J. Good (with the Manchester Mark I and other early Manchester computers). Alan Mathison Turing, OBE, FRS (ˈt(jʊ(ərɪŋ (23 June 1912 &ndash 7 June 1954 was an English Mathematician The Pilot ACE was one of the first Computers built in the United Kingdom, at the National Physical Laboratory (NPL in the early 1950s The Automatic Computing Engine ( ACE) was an early Electronic stored-program Computer design produced by Alan Turing at the invitation of John Irving John (Jack Good (born 9 December 1916) is a British Statistician who worked also as a Cryptographer at Bletchley Park This article is about the early British computer. The term "Manchester Mark I" can also refer to the Avro Manchester heavy bomber in RAF service during Brian Randell later wrote that:

"the COLOSSUS project was an important source of this vitality, one that has been largely unappreciated, as has the significance of its places in the chronology of the invention of the digital computer". Brian Randell is a British Computer scientist, specializing in research in Software Fault tolerance and Dependability. [3]

Colossus documentation and hardware were classified from the moment of their creation and remained so after the War, when Winston Churchill specifically ordered the destruction of most of the Colossus machines into 'pieces no bigger than a man's hand'; Tommy Flowers personally burned blueprints in a furnace at Dollis Hill. Sir Winston Leonard Spencer-Churchill, KG, OM, CH, TD, FRS, PC, PC (Can ( 30 November 1874 Some parts, sanitised as to their original use, were taken to Newman's Computing Machine Laboratory at Manchester University. The University of Manchester is a " red brick " civic University located in Manchester, England. The Colossus Mark I was dismantled and parts returned to the Post Office. Two Colossus computers, along with two replica Tunny machines, were retained, moving to GCHQ's new headquarters at Eastcote in April 1946, and moving again with GCHQ to Cheltenham between 1952 and 1954. The Government Communications Headquarters (GCHQ is a British Intelligence agency responsible for providing Signals intelligence (SIGINT and Information Eastcote is a place in the London Borough of Hillingdon. The 2001 UK census gave the population of the Eastcote and South Ruislip Ward as 11480 Education [4] One of the Colossi, known as Colossus Blue, was dismantled in 1959; the other in 1960. [4] In their later years, the Colossi were used for training, but before that, there had been attempts to adapt them, with varying success, to other purposes. [5] Jack Good relates how he was the first to use it after the war, persuading NSA that Colossus could be used to perform a function for which they were planning to build a special purpose machine. The National Security Agency/ Central Security Service ( NSA/CSS) is a cryptologic intelligence agency of the United States government [4] Colossus was also used to perform character counts on one-time pad tape to ensure their randomness. [4]

Information about Colossus began to emerge publicly in the late 1970s, after the secrecy imposed was broken when Colonel Winterbotham published his book 'The Ultra Secret'. This article is about the Decade 1970-1979 For the Year 1970 see 1970. More recently, a 500-page technical report on the Tunny cipher and its cryptanalysis – entitled General Report on Tunny – was released by GCHQ to the national Public Record Office in October 2000; the complete report is available online,[6] and it contains a fascinating paean to Colossus by the cryptographers who worked with it:

It is regretted that it is not possible to give an adequate idea of the fascination of a Colossus at work; its sheer bulk and apparent complexity; the fantastic speed of thin paper tape round the glittering pulleys; the childish pleasure of not-not, span, print main header and other gadgets; the wizardry of purely mechanical decoding letter by letter (one novice thought she was being hoaxed); the uncanny action of the typewriter in printing the correct scores without and beyond human aid; the stepping of the display; periods of eager expectation culminating in the sudden appearance of the longed-for score; and the strange rhythms characterizing every type of run: the stately break-in, the erratic short run, the regularity of wheel-breaking, the stolid rectangle interrupted by the wild leaps of the carriage-return, the frantic chatter of a motor run, even the ludicrous frenzy of hosts of bogus scores. The Government Communications Headquarters (GCHQ is a British Intelligence agency responsible for providing Signals intelligence (SIGINT and Information The Public Record Office (PRO of the United Kingdom is one of the three organisations that make up the National Archives (the others are the Historical Manuscripts 2000 ( MM) was a Leap year that started on Saturday of the Common Era, in accordance with the Gregorian calendar. Paean (pronounced as the last two syllables of "European" ˈpiːən is a term used to describe a type of triumphal or grateful song usually choral though sometimes individual [7]

## Reconstruction

Construction of a fully-functional replica[8] of a Colossus Mark II has been undertaken by a team led by Tony Sale. Anthony Edgar Sale (or Tony Sale) (born 30 January 1931) is popularly known for leading the rebuilding of the Colossus computer which was completed In spite of the blueprints and hardware being destroyed, a surprising amount of material survived, mainly in engineers' notebooks, but a considerable amount of it in the US. The optical tape reader might have posed the biggest problem, but Dr. Arnold Lynch its original designer was able to redesign it to his own original specification. The reconstruction is on display, in the historically correct place for Colossus No. 9, in H Block Bletchley Park Museum in Milton Keynes, Buckinghamshire. Bletchley Park, also known as Station X, is an estate located in the town of Bletchley, in Buckinghamshire, and (since 1967 part of Milton Keynes Milton Keynes ( ˌmɪltənˈkiːnz often abbreviated to MK, is a large town Buckinghamshire (abbreviated Bucks) is a ceremonial and non-metropolitan home county in South East England. In November 2007, to celebrate the project completion and to mark the start of a fundraising initiative for the The National Museum of Computing, a Cipher Challenge[9] pitted the rebuilt Colossus against radio amateurs worldwide in being first to receive and decode 3 messages enciphered using the Lorenz SZ42 and transmitted from radio station DL0HNF in the Heinz Nixdorf MuseumsForum computer museum. The National Museum of Computing is a Museum documenting the history of the Computer sciences based at Bletchley Park in the United Kingdom. "Tunny" redirects here For the fish see Tuna. The Lorenz SZ 40 and SZ 42 ( Schlüsselzusatz, meaning The challenge was easily won by radio amateur Joachim Schüth who had carefully prepared[10] for the event and developed his own signal processing and decrypt code using Ada. See also Amateur radio An amateur radio operator is an individual who typically uses equipment at an Amateur radio station to engage in two-way Ada is a structured, Statically typed, imperative, and object-oriented high-level computer Programming language The Colossus team were hampered by their wish to use WW2 radio equipment[11], delaying them by a day because of poor reception conditions. World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including Nevertheless the victor's 1. 4GHz laptop, running his own code, took less than a minute to find the settings for all 12 wheels. A laptop computer, also known as a notebook computer, is a small Personal computer designed for mobile use. The German codebreaker said: “My laptop digested ciphertext at a speed of 1. 2 million characters per second – 240 times faster than Colossus. If you scale the CPU frequency by that factor, you get an equivalent clock of 5. 8 MHz for Colossus. That is a remarkable speed for a computer built in 1944. "[12]

The Cipher Challenge verified the successful completion of the rebuild project. "On the strength of today's performance Colossus is as good as it was six decades ago," commented Tony Sale. "We are delighted to have produced a fitting tribute to the people who worked at Bletchley Park and whose brainpower devised these fantastic machines which broke these ciphers and shortened the war by many months. "[13]

## Footnotes

1. ^ Jack Copeland, "Machine against Machine", p. The history of computer hardware encompasses the hardware, its architecture, and its impact on software. Konrad Zuse 's A supercomputer is a Computer that is at the frontline of processing capacity particularly speed of calculation (at the time of its introduction 75 (entire article pp. 64-77) in B. Jack Copeland, ed. , Colossus: The Secrets of Bletchley Park's Codebreaking Computers, Oxford University Press, 2006
2. ^ The Computer from Pascal to von Neuman (pp. 321)
3. ^ B. Randell, "The Colossus", in A History of Computing in the Twentieth Century (N. Metropolis, J. Howlett and G. C. Rota, Eds. ), pp. 47-92, Academic Press, New York, 1980. , p. 87
4. ^ a b c d Copeland, 2006, p. 173-175
5. ^ Horwood, 1973
6. ^ Jack Good; Donald Michie, and Geoffrey Timms (1945). General Report on Tunny.
7. ^ http://www.alanturing.net/turing_archive/archive/t/t17/TR17-003.html.
8. ^ Colossus Rebuild Project.
9. ^ Cipher Challenge.
10. ^ SZ42 Codebreaking Software.
11. ^ BBC News Article.
12. ^ German Codebreaker receives Bletchley Park Honours.
13. ^ Latest Cipher Challenge News 16.11.2007.

## References

• W. W. Chandler, The Installation and Maintenance of Colossus (IEEE Annals of the History of Computing, Vol. The IEEE Annals of the History of Computing is a quarterly Journal published by the IEEE Computer Society. 5 (No. 3), 1983, pp. 260–262)
• Allen W. M. Coombs, The Making of Colossus (Annals of the History of Computing, Vol. Allen William Mark (Doc Coombs ( 23 October 1911 &ndash 30 January 1995) was a British electronics engineer at the Post Office Research 5 (No. 3), 1983, pp. 253-259)
• Jack Copeland, Colossus: Its Origins and Originators (IEEE Annals of the History of Computing, 26(4), October–December 2004, pp. The IEEE Annals of the History of Computing is a quarterly Journal published by the IEEE Computer Society. 38–45).
• Jack Copeland, Colossus and the Dawning of the Computer Age, in Action This Day, 2001, ISBN 0-593-04982-9.
• B. Jack Copeland (editor), Colossus: The Secrets of Bletchley Park's Codebreaking Computers, 2006, Oxford University Press, ISBN 0-19-284055-X.
• I. J. Good, Early Work on Computers at Bletchley (IEEE Annals of the History of Computing, Vol. Irving John (Jack Good (born 9 December 1916) is a British Statistician who worked also as a Cryptographer at Bletchley Park The IEEE Annals of the History of Computing is a quarterly Journal published by the IEEE Computer Society. 1 (No. 1), 1979, pp. 38–48)
• I. J. Good, Pioneering Work on Computers at Bletchley (in Nicholas Metropolis, J. Irving John (Jack Good (born 9 December 1916) is a British Statistician who worked also as a Cryptographer at Bletchley Park Howlett, Gian-Carlo Rota, (editors), A History of Computing in the Twentieth Century, Academic Press, New York, 1980)
• T. H. Flowers, The Design of Colossus (Annals of the History of Computing, Vol. Thomas (Tommy Harold Flowers MBE ( 22 December 1905 &ndash 28 October 1998) was an English engineer 5 (No. 3), 1983, pp. 239–252)
• D C Horwood, A technical description of COLOSSUS I, August 1973, PRO HW 25/24.
• Brian Randell, Colossus: Godfather of the Computer, 1977 (reprinted in The Origins of Digital Computers: Selected Papers, Springer-Verlag, New York, 1982)
• Brian Randell, The COLOSSUS (in A History of Computing in the Twentieth Century)
• Albert W. Brian Randell is a British Computer scientist, specializing in research in Software Fault tolerance and Dependability. Springer Science+Business Media or Springer (ˈʃpʁɪŋɐ is a worldwide Publishing company based in Germany, which publishes textbooks academic Brian Randell is a British Computer scientist, specializing in research in Software Fault tolerance and Dependability. Small, The Special Fish Report (December, 1944) describe the operation of Colossus to break Tunny messages