Micro Computers

The introduction of the first general purpose microprocessors inevitably led to the first microcomputers around 1975. At the time these systems were of limited utility, and Ken Olsen famously derided them in 1977, stating "There is no reason for any individual to have a computer in his home."[43] Unsurprisingly, DEC did not put much effort into the microcomputer area in the early days of the market. In the 1980s, DEC built the VT180 (codenamed "Robin"), which was a VT100 terminal with a Z80-based microcomputer running CP/M.


It was only after IBM had successfully launched the IBM PC that DEC responded with their own systems. Digital responded by introducing not one, but three incompatible machines which were tied to proprietary architectures. The first, the DEC Professional, was based on the PDP-11/23 (the 11/73) running the RSX-11M+ derived, menu-driven, P/OS. The idea was to introduce a machine that outperformed the PC, but in doing so they created one that was more difficult to learn and use[citation needed] than PC-DOS or CP/M which were more commonly used on the 8080 and 8088 based microcomputers of the time. The DECmate was the latest version of the PDP-8 based word processors, but not really suited to general computing, nor competitive with Wang Laboratories word processing that was becoming popular.


The best known of DEC's early microcomputers is the Rainbow 100, which ran an 8086 implementation of CP/M. Applications from standard CP/M could be re-compiled for the Rainbow, but, by this time, users were expecting custom-built applications such as Lotus 1-2-3, which was eventually ported along with MS-DOS 2.0 and introduced in late 1983. Users also objected to having to buy preformatted floppy disks. Although the Rainbow generated some press, it was unsuccessful due to its high price and lack of marketing and sales support.


A further system was introduced in 1986 as the VAXmate, which included Microsoft Windows 1.0 and used VAX/VMS-based file and print servers along with integration into DEC's own DECnet-family, providing LAN/WAN connection from PC to mainframe or supermini. The VAXmate replaced the Rainbow and in its standard form was the first diskless workstation.

The construction of Micro Computers

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. 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 assembled by Harry Fensom and Don Horwood, and attacked its first message on 5 February.

The Mark 1 was followed by nine Mark 2 Colossus machines, the first being commissioned in June 1944, and the original Mark 1 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. For comparison, later stored-program computers like the Manchester Mark 1 of 1949 used about 4,200 valves. In comparison, ENIAC (1946) used 17,468 valves, but, unlike Colossus, was not a software programmable machine.

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 (12.2 m/s or 27.3 mph). The circuits were synchronized by a clock signal generated by the sprocket holes of the punched tape. 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 (53 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, speeding the decoding process by perhaps as much as doubling the rate of comparison.

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).

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.

Reconstruction

Construction of a fully-functional replica of a Colossus Mark 2 was undertaken by a team led by Tony Sale. 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 U.S. 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, at The National Museum of Computing, in H Block Bletchley Park in Milton Keynes, Buckinghamshire.


In November 2007, to celebrate the project completion and to mark the start of a fundraising initiative for The National Museum of Computing, a Cipher Challenge pitted the rebuilt Colossus against radio amateurs worldwide in being first to receive and decode three messages enciphered using the Lorenz SZ42 and transmitted from radio station DL0HNF in the Heinz Nixdorf MuseumsForum computer museum. The challenge was easily won by radio amateur Joachim Schüth, who had carefully prepared for the event and developed his own signal processing and decrypt code using Ada. The Colossus team were hampered by their wish to use World War II radio equipment, delaying them by a day because of poor reception conditions. Nevertheless the victor's 1.4 GHz laptop, running his own code, took less than a minute to find the settings for all 12 wheels. 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."

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.

Latest Version Of Colossus Computer Specification, Features & Price

Colossus ComputerDigital modules

In early 1958 DEC shipped its first products, the "Digital Laboratory Module" line. The Modules consisted of a number of individual electronic components and germanium transistors mounted to a circuit board, the actual circuits being based on those from the TX-2.

The Laboratory Module were packaged in an extruded aluminum housing, intended to sit on an engineer's workbench. They were then connected together using banana plug patch cords inserted at the front of the modules. Three versions were offered, running at 5 MHz (1957), 500 kHz (1959), or 10 MHz (1960). The Modules proved to be in high demand in other computer companies, who used them to build equipment to test their own systems. Despite the recession of the late 1950s, the company sold $94,000 worth of these modules during 1958 alone, turning a profit at the end of its first year.

The original Laboratory Modules were soon supplemented with the "Digital Systems Module" line, which were identical internally but packaged differently. The Systems Modules were designed with all of the connections at the back of the module using 22-pin Amphenol connectors, and were attached to each other by inserting them into a custom 19-inch rack. These versions allowed 25 modules be to inserted into a single 5-1/4 inch section of racking, and allowed the high densities needed to build a computer. DEC used the Systems Modules to build their "Memory Test" machine for testing core memory systems, selling about 50 of these pre-packaged units over the next eight years.

Modules were part of DEC's product line into the 1970s, although they went through several evolutions during this time as technology changed. The same circuits were then packaged as the first "R" (red) series "Flip-Chip" modules. Later, other module series provided additional speed, much higher logic density, and industrial I/O capabilities. Digital published extensive data about the modules in free catalogs that became very popular.

With the company established and a successful product on the market, DEC turned its attention to the computer market once again as part of its planned "Phase II". In August 1959, Ben Gurley started design of the company's first computer, the PDP-1. In keeping with Doriot's instructions, the name was an initialism for "Programmable Data Processor", leaving off the term "computer". As Gurley put it, "We aren't building computers, we're building 'Programmable Data Processors'." The prototype was first shown publicly at the Joint Computer Conference in Boston in December 1959.

The PDP-1 design was based on a number of System Building Blocks packaged into several 19-inch racks to form an 18-bit word computer, supplied standard with 4 kWords of core memory and running at a basic speed of 100,000 operations per second. The racks were themselves packaged into a single large mainframe case, with a hexagonal control panel containing switches and lights mounted to lay at table-top height at one end of the mainframe. Above the control panel was the system's standard input/output solution, a punch tape reader and writer. Most systems were purchased with two peripherals, the Type 30 vector graphics display, and a Soroban Engineering modified IBM Model B Electric typewriter that was used as a printer. The Soroban system was notoriously unreliable, and often replaced with a modified Friden Flexowriter, which also contained its own punch tape system. A variety of more-expensive add-ons followed, including magnetic tape systems, punched card readers and writers, and faster punch tape and printer systems.

The first PDP-1 was delivered to Bolt, Beranek and Newman in November 1960, and formally accepted the next April. In 1962 DEC donated the prototype PDP-1 to MIT, where it was placed in the room next to the TX-0. In this setting the PDP-1 quickly replaced the TX-0 as the favourite machine among the budding hacker culture, and served as the platform for a wide variety of "firsts" in the computing world. Perhaps best known among these is the first computerized video game, Spacewar!, but among the list are the first text editor, word processor, interactive debugger, the first credible computer chess program, and some of the earliest computerized music.

The PDP-1 sold in basic form for $120,000, or about $780,000 in 2005-era USD.[ BBN's system was quickly followed by orders from Lawrence Livermore and Atomic Energy of Canada (AECL), and eventually 53 PDP-1s were delivered until production ended in 1969. All of these machines were still being actively used in 1970, and several were eventually saved. MIT's example was donated to The Computer Museum, Boston, and from there ended up at the Computer History Museum (CHM). A late version of Spacewar! on paper tape was still tucked into the case. PDP-1 #44 was found in a barn in Wichita, Kansas in 1988, apparently formerly owned by one of the many aviation companies in the area, and rescued for the Digital Historical Collection, also eventually ending up at the CHM. AECLs was sent to Science North, but was later scrapped.

When DEC introduced the PDP-1, they also mentioned larger machines at 24, 30 and 36-bits, based on the same design. During construction of the prototype PDP-1, some design work was carried out on a 24-bit PDP-2, and the 36-bit PDP-3. Although the PDP-2 never proceeded beyond the initial design, the PDP-3 found some interest and was designed in full. Only one PDP-3 appears to have been built, in 1960, by the CIA's Scientific Engineering Institute (SEI) in Waltham, Massachusetts. According to the limited information available, they used it to process radar cross section data for the Lockheed A-12 reconnaissance aircraft. Gordon Bell remembered that it was being used in Oregon some time later, but could not recall who was using it.

In November 1962 DEC introduced the $65,000 PDP-4. The PDP-4 was similar to the PDP-1 and used a similar instruction set, but used slower memory and different packaging to lower the price. Like the PDP-1, about 54 PDP-4's were eventually sold, most to a customer base similar to the original PDP-1.

In 1964 DEC introduced its new Flip Chip module design, and used it to re-implement the PDP-4 as the PDP-7. The PDP-7 was introduced in December 1964, and about 120 were eventually produced. An upgrade to the Flip Chip led to the R series, which in turn led to the PDP-7A in 1965. The PDP-7 is most famous as the original machine for the Unix operating system.

A more dramatic upgrade to the PDP-1 series was introduced in August 1966, the PDP-9.[26] The PDP-9 was instruction compatible with the PDP-4 and -7, but ran about twice as fast as the -7 and was intended to be used in larger deployments. At only $19,900 in 1968, the PDP-9 was a big seller, eventually selling 445 machines, more than all of the earlier models combined.

Even while the PDP-9 was being introduced, its replacement was being designed, and was introduced as 1969's PDP-15, which re-implemented the PDP-9 using integrated circuits in place of modules. Much faster than the PDP-9 even in basic form, the PDP-15 also included a floating point unit and a separate input/output processor for further performance gains. Over 400 PDP-15's were ordered in the first eight months of production, and production eventually amounted to 790 examples in twelve basic models. However, by this time other machines in DEC's lineup could fill the same niche at even lower price points, and the PDP-15 would be the last of the 18-bit series.

In 1962, Lincoln Laboratory used a selection of System Building Blocks to implement a small 12-bit machine, and attached it to a variety of analog-to-digital (A to D) input/output (I/O) devices that made it easy to interface with various analog lab equipment. The LINC proved to attract intense interest in the scientific community, and has since been referred to as the first real minicomputer, a machine that was small and inexpensive enough to be dedicated to a single task even in a small lab.

Seeing the success of the LINC, in 1963 DEC took the basic logic design but stripped away the extensive A to D systems to produce the PDP-5. The new machine, the first outside the PDP-1 mould, was introduced at WESTCON on 11 August 1963. A 1964 ad expressed the main advantage of the PDP-5, "Now you can own the PDP-5 computer for what a core memory alone used to cost: $27,000" 116 PDP-5s were produced until the lines were shut down in early 1967. Like the PDP-1 before it, the PDP-5 inspired a series of newer models based on the same basic design that would go on to be more famous than its parent.

On 22 March 1965, DEC introduced the PDP-8, which replaced the PDP-5's modules with the new R-series modules using Flip Chips. The machine was re-packaged into a small tabletop case, which remains distinctive for its use of smoked plastic over the CPU which allowed one to easily see the wire-wrapped internals of the CPU. Sold standard with 4 kWords of 12-bit core memory and a ASR-33 Teletype for basic input/output, the machine listed for only $18,000. The PDP-8 is referred to as the first real minicomputer because of its sub-$25,000 price. Sales were, unsurprisingly, very strong, and helped by the fact that several competitors had just entered the market with machines aimed directly at the PDP-5's market space, which the PDP-8 trounced. This gave the company two years of unrestricted leadership, and eventually 1450 "straight eight" machines were produced before it was replaced by newer implementations of the same basic design.

DEC hit an even lower price-point with the PDP-8/S, the S for "serial". As the name implies the /S used a serial arithmetic unit, which was much slower but reduced costs so much that the system sold for under $10,000. DEC then used the new PDP-8 design as the basis for a new LINC, the two-processor LINC-8. The LINC-8 used one PDP-8 CPU and a separate LINC CPU, and included instructions to switch from one to the other. This allowed customers to run their existing LINC programs, or "upgrade" to the PDP-8, all in software. Although not a huge seller, 142 LINK-8s were sold starting at $38,500. Like the original LINC to PDP-5 evolution, the LINC-8 was then modified into the single-processor PDP-12, adding another 1000 machines to the 12-bit family. Newer circuitry designs led to the PDP-8/I and PDP-8/L in 1968.[11] In 1975, one year after an agreement between Digital and Intersil, the Intersil 6100 chip was launched, effectively a PDP-8 on a chip. This was a way to allow PDP-8 software to be run even after the official end-of-life announcement for the Digital PDP-8 product line.


While the PDP-5 introduced a lower-cost line, 1963's PDP-6 was intended to take DEC into the mainframe market with a 36-bit machine. However, the PDP-6 proved to be a "hard sell" with customers, as it offered few advantages over similar machines from the better established vendors like IBM or Honeywell, in spite of its low cost around $300,000. Only 23 were sold,[36] or 26 depending on the source, and unlike earlier models the low sales meant the PDP-6 was not improved with intermediate versions. However, the PDP-6 is historically important as the platform that introduced "Monitor", an early time-sharing operating system that would evolve into the widely used TOPS-10.

In spite of the PDP-6's limited commercial success, it introduced many features that clearly had commercial benefit. When the Flip Chip packaging allowed the PDP-6 to be re-implemented at a much lower cost, DEC took the opportunity to carry out a similar evolution of their 36-bit design and introduced the PDP-10 in 1968. The PDP-10 was as much a success as the PDP-6 was a failure; during its lifetime about 700 mainframe PDP-10's were sold before production ended in 1984. The PDP-10 was widely used in university settings, and thus was the basis of many advances in computing and operating system design during the 1970s. DEC later re-branded all of the models in the 36-bit series as the "DECsystem-10", and PDP-10's are generally referred to by the model of their CPU, like "KA10". Later upgrades produced the compatible DECSYSTEM-20, along with TOPS-20 that included virtual memory.

One of the most unusual peripherals produced for the PDP-10 was the DECtape. The DECtape was a length of standard magnetic tape wound on 5-in reels. However, the recording format was a 10-track approach using fixed-length numbered 'blocks' organized into a standard file structure, including a directory. Files could be written, read, changed, and deleted on a DECtape as though it were a disk. In fact, some PDP-10 systems had no disks at all, using DECtapes alone for their primary data storage. For greater efficiency, the DECtape drive could read and write to a DECtape in both directions.

In 1968 DEC was working on a PDP machine that would be based on 8-bit bytes instead of 6-bit characters. Known as the "PDP-X", the project was eventually cancelled. Several team members decamped and set up Data General in May 1968, and rapidly brought the 16-bit NOVA minicomputer to market. DEC immediately found itself behind in the industry transition to 8-bit bytes, and soon lost its crown as the largest minicomputer vendor.

The PDP-11 16-bit computer was designed in a crash program by Harold McFarland, Gordon Bell, Roger Cady, and others. The project was able to leap forward in design with the arrival of Harold McFarland, who had been researching 16-bit designs at Carnegie Mellon University. One of his simpler designs became the PDP-11, although when they first presented it, management was not impressed and almost cancelled it.

In particular, the new design did not include many of the addressing modes that were intended to make programs smaller in memory, a technique that was widely used on other DEC machines and CISC designs in general. This would mean the machine would spend more time accessing memory, which would slow it down. However, the machine also introduced the idea of "General Registers", which gave the programmer flexibility to use these high-speed memory caches as they needed, potentially addressing the performance issues.

A major advance in the PDP-11 design was UNIBUS, which supported all peripherals through memory mapping. This allowed new devices to be added easily, generally only requiring some sort of hardware interface and then writing software that examined the mapped memory to control them. This spawned a huge market of 3rd party add-ons for the PDP-11, which made the machine even more useful.

Its numerous architectural innovations proved superior to all competitors and the "11" architecture was soon the industry leader, propelling DEC back to their leadership position. The design was later expanded to allow paged physical memory and memory protection features, useful for multitasking and time-sharing, and some models supported separate instruction and data spaces for an effective virtual address size of 128 kB within a physical address size of up to 4 MB. PDP-11s, implemented as single-chip CPUs, continued to be produced until 1996, by which time over 600,000 had been sold.

The PDP-11 supported several operating systems, including Bell Labs' new Unix operating system as well as DEC's DOS-11, RSX-11, IAS, RT-11, DSM-11, and RSTS/E. Many early PDP-11 applications were developed using standalone paper-tape utilities. DOS-11 was the PDP-11's first disk operating system, but was soon supplanted by more capable systems. RSX provided a general-purpose multitasking environment and supported a wide variety of programming languages. IAS was a time-sharing version of RSX-11D. Both RSTS and Unix were time-sharing systems available to educational institutions at little or no cost, and these PDP-11 systems were destined to be the sandbox for a generation of engineers and computer scientists. Large numbers of 11/70s were deployed in telecommunications and industrial control applications. AT&T became DEC's largest customer.

RT-11 provided a practical real-time operating system, allowing the PDP-11 to continue Digital's critical role as a computer supplier for embedded systems. RT-11 served as the inspiration for many microcomputer OS's, as these were generally being written by programmers who cut their teeth on one of the many PDP-11 models. CP/M used a command syntax similar to RT-11's, and even retained the awkward PIP program used to copy other programs. DEC's use of "/" for "switches" (command-line options) would lead to the adoption of "\" for pathnames in MS-DOS and Microsoft Windows as opposed to "/" in Unix.

The evolution of the PDP-11 followed earlier systems, eventually evolving into a single-user deskside personal computer form in the microPDP. 600,000 PDP-11's of all models were eventually sold. Many PDP-11-like machines were also introduced, and a wide variety of peripheral vendors entered the ecosystem. The PDP-11 series was cloned in COMECON countries as the SM EVM series, and was produced in quantities comparable to original PDP-11 production.


In 1976, DEC decided to extend the PDP-11 architecture to 32-bits while adding a complete virtual memory system to the simple paging and memory protection of the PDP-11. The result was the VAX architecture. The first computer to use a VAX CPU was the VAX-11/780, which DEC referred to as a superminicomputer. Although it was not the first 32-bit minicomputer, the VAX-11/780's combination of features, price, and marketing almost immediately propelled it to a leadership position in the market after it was released in 1978. VAX systems were so successful that in 1983, DEC canceled its Jupiter project, which had been intended to build a successor to the PDP-10 mainframe, and instead focused on promoting the VAX as their the single computer architecture for the company.

Supporting the VAX's success was the VT52, one of the most successful smart terminals. Building on earlier less successful models (the VT05 and VT50), the VT52 was the first terminal that did everything one might want in a single chassis. The VT52 was followed by the even more successful VT100 and its follow-ons, making DEC one of the largest terminal vendors in the industry. With the VT series, DEC could now offer a complete top-to-bottom system from computer to all peripherals, which formerly required collecting the required devices from different suppliers.

The VAX processor architecture and family of systems evolved and expanded through several generations during the 1980s, culminating in the NVAX microprocessor implementation and VAX 7000/10000 series in the early 1990s

Colossus Computer

Digital Computers

Colossus computer

The Colossus machines were electronic computing devices used by British codebreakers to help read encrypted German messages during World War II. These were the world's first programmable, digital, electronic, computing devices. They used vacuum tubes (thermionic valves) to perform the calculations.

Colossus was designed by engineer Tommy Flowers with input from Harry Fensom, Allen Coombs, Sid Broadhurst and Bill Chandler[1] at the Post Office Research Station, Dollis Hill to solve a problem posed by mathematician Max Newman at Bletchley Park. The prototype, Colossus Mark 1, was shown to be working in December 1943 and was operational at Bletchley Park by February 1944. An improved Colossus Mark 2 first worked on 1 June 1944, just in time for the Normandy Landings. Ten Colossi were in use by the end of the war.

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 "Tunny". Colossus compared two data streams, counting each match based on a programmable Boolean function. 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 sent as output to an electric typewriter.

The Colossus was used to find possible key combinations for the Lorenz machines – rather than decrypting an intercepted message in its entirety.

In spite of the destruction of the Colossus hardware and blueprints as part of the effort to maintain a project secrecy that was kept up into the 1970s—a secrecy that deprived some of the Colossus creators of credit for their pioneering advancements in electronic digital computing during their lifetimes—a functional replica of a Colossus computer was completed in 2007.

Purpose and origins

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 electromechanical Lorenz machine electronically. To encrypt a message with the Lorenz machine, the plaintext was combined with a stream of key bits, grouped in fives. The keystream was generated using twelve pinwheels: five were termed (by the British) ? ("chi") wheels, another five ? ("psi") wheels, and the remaining two the "motor wheels". The ? wheels stepped regularly with each letter that was encrypted, while the ? 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. 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 developed for the Newmanry, the section at Bletchley Park responsible for machine methods against the Lorenz machine, headed by the mathematician Max Newman. It arose out of a prior project which produced a special purpose opto-mechanical comparator and counting machine called "Heath Robinson".

The main problems with the Heath Robinson were the relative slowness of electro-mechanical relays and the difficulty of synchronising two paper tapes, one punched with the enciphered message, the other representing the patterns produced by the wheels of the Lorenz machine. The tapes tended to stretch when being read at some 2000 characters per second, resulting in unreliable counts. Tommy Flowers of the Post Office Research Station at Dollis Hill was called in to look into the design of the Robinson’s combining unit. He was not impressed with the machines and, at his own initiative, designed an electronic machine which stored the data from one of the tapes internally. He presented this design to Max Newman in February 1943, but the idea that the one to two thousand thermionic valves (vacuum tubes) proposed, could work together reliably was greeted with scepticism, so more Robinsons were ordered from Dollis Hill. Flowers, however, persisted with the idea and obtained support from the Director of the Research Station.

Design and operation

 

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". 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 when powering up, 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. 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 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.

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.). The Atanasoff–Berry Computer was electronic and binary (digital) but not programmable. Assorted analog computers were semiprogrammable; some of these much predated the 1930s (e.g., Vannevar Bush). Babbage's Analytical engine design predated all these (in the mid-19th century), it was a decimal, programmable, entirely mechanical construction—but was only partially built and never functioned during Babbage's lifetime (the first complete mechanical Difference engine No. 2, built in 1991, does work however). Colossus was the first combining digital, (partially) programmable, and electronic. The first fully programmable digital electronic computer was the ENIAC which was completed in 1946.

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I love laying in bed at night talking about nothing.
 
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I love the surprises you leave for me.
 
I love your intelligence.
 
I love your ingenuity.
 
I love your ability to make friends where ever we go.
 
I love your love for life.
 
I love your passion for your hobbies and interests.
 
I love how every time I look at you, you take my breath away.
 
I love how I thank God everyday for bringing someone as wonderful as you into my life.
 
I love the fact you gave me the gift of our children.
 
I love the special moments that we shared that will remain my fondest memories of you and I.
 
I love spending the holidays with the one person I love the most.
 
I love how my heart skips a beat whenever you walk into the room.
 
I love how you love me.
 
I love how I love you.
 
I love the ways you choose to show your affection for me.
 
I love the way you inspire me to be more than I am.
 
I love the way you spark my creativity and imagination.
 
I love the way you make me feel like anything is possible as long as I'm with you.
 
I love your sense of humor.

I love the way you make me feel like royalty.
 
I love the way you dress.
 
I love your understated elegance.

I love you just the way you are.
 
I love your spontaneity.
 
I love our life together.
 
I love how if I died right now I would be the happiest person alive knowing I found my one true love.
 
I love the fact that we will grow old together.
 
I love your way with words.
 
I love the way you look when your sleeping.
 
I love the way you think you look awful when you first wake up when it is actually then I find you the most beautiful.
 
I love your willingness to share everything and most especially your heart with me.
 
I love your strength of character.
 
I love taking showers together.
 
I love the way you leave me love notes to find whenever you're gone.
 
I love the way you treat me.
 
I love the way you take care of us.
 
I love your cooking.
 
I love the way you take the time to thank me for doing every day things.
 
I love the way you show your affection when we are around friends and/or family.
 
I love the way you are not scared to show your affection when we are in public.
I love your confidence.
 
I love your ability to make me feel better when times are tough.
 
I love the way we make up after a fight.
 
I love how you treat our children.
 
I love the way you support me when I'm off track.
 
I love the way you take the time to show me how much you love me.
 
I love your beautiful hair.
 
I love your ody.
 
I love your openness to try new things.
 
I love your ability to talk things through.
 
I love your courage to be you.
 
I love your greatness.
 
I love the fact that you want to be with me and only me.
 
I love how I am and feel when I am with you!
 
I love you for you!

Worlds Popular (Latest) Super Computers Features, Review & Price

Computer Modern

supercomputer is a computer that is at the frontline of current processing capacity, particularly speed of calculation. Supercomputers introduced in the 1960s were designed primarily by Seymour Cray at Control Data Corporation (CDC), and led the market into the 1970s until Cray left to form his own company, Cray Research. He then took over the supercomputer market with his new designs, holding the top spot in supercomputing for five years (1985–1990). In the 1980s a large number of smaller competitors entered the market, in parallel to the creation of the minicomputer market a decade earlier, but many of these disappeared in the mid-1990s "supercomputer market crash".

The era in which computing power doubles every two years is drawing to a close, according to the man behind Moore's Law Jonathan Richards For decades it has been the benchmark by which advancements in computing are measured. Now Moore's Law - the maxim which states that computers double in speed roughly every two years - has come under threat, from none other than the man who coined it. Gordon Moore, the retired co-founder of Intel, wrote an influential paper in 1965 called 'Cramming more components onto integrated circuits', in which he theorised that the number of transistors on a computer chip would double at a constant rate. Silicon Valley has kept up with his widely accepted maxim for more than 40 years, to the point where a new generation of chips, which Intel will begin to produce next year, will have transistors so tiny that four million of them could fit on the head of a pin. Related Links * IBM unveils nanotechnology chip advance * Intel chips away at AMD * Intel apologises for 'racist' ad In an interview yesterday, however, Mr Moore said by about 2020, his law would come up against a rather intractable stumbling block: the laws of physics. "Another decade, a decade and a half, I think we'll hit something fairly fundamental," Mr Moore said at Intel's twice-annual technology conference. Then Moore's Law will be no more. The current method of Silicon-based manufacturing is known as "bulk CMOS", which is essentially a 'top-down' approach, where the maker starts with a piece of Silicon and 'etches out' the parts that aren't needed. "It's all very well having multicore chips in desktop machines, but if the software does not take advantage of them, you gain no benefit." "We are hitting the software barrier before we hit the physical barrier," he said. Mr Moore, who is 78, pioneered the design of the integrated circuit, and went on to co-found Intel in 1968, where he served as chief executive between 1975 and 1987.
Apple Inc. (previously Apple Computer, Inc.) is an American multinational corporation that designs and markets consumer electronics, computer software, and personal computers. The company's best-known hardware products include the Macintosh computers, the iPod, the iPhone and the iPad. Apple software includes the Mac OS X operating system; the iTunes media browser; the iLife suite of multimedia and creativity software; the iWork suite of productivity software; Aperture, a professional photography package; Final Cut Studio, a suite of professional audio and film-industry software products; and Logic Studio, a suite of audio tools. As of January 2010, the company operates 284 retail stores in ten countries,and an online store where hardware and software products are sold.
Established on April 1, 1976 in Cupertino, California, and incorporated January 3, 1977, the company was previously named Apple Computer, Inc. for its first 30 years, but removed the word "Computer" on January 9, 2007, to reflect the company's ongoing expansion into the consumer electronics market in addition to its traditional focus on personal computers. As of September 26, 2009, Apple had 34,300 full time employees and 2,500 temporary full time employees worldwide and had worldwide annual sales of $42.91 billion in its fiscal year ending September 26, 2009.

For reasons as various as its philosophy of comprehensive aesthetic design to its distinctive advertising campaigns, Apple has established a unique reputation in the consumer electronics industry. This includes a customer base that is devoted to the company and its brand, particularly in the United States. Fortune magazine named Apple the most admired company in the United States in 2008, and in the world in 2008, 2009, and 2010. In May 2010, Apple's market cap exceeded that of Microsoft for the first time since 1989
1998–2005: Return to profitabilityOn August 15, 1998, Apple introduced a new all-in-one computer reminiscent of the Macintosh 128K: the iMac. The iMac design team was led by Jonathan Ive, who would later design the iPod and the iPhone. The iMac featured modern technology and a unique design. It sold close to 800,000 units in its first five months.
Through this period, Apple purchased several companies to create a portfolio of professional and consumer-oriented digital production software. In 1998, Apple announced the purchase of Macromedia's Final Cut software, signaling its expansion into the digital video editing market. The following year, Apple released two video editing products: iMovie for consumers, and Final Cut Pro for professionals, the latter of which has gone on to be a significant video-editing program, with 800,000 registered users in early 2007. In 2002 Apple purchased Nothing Real for their advanced digital compositing application Shake, as well as Emagic for their music productivity application Logic, which led to the development of their consumer-level GarageBand application. iPhoto's release the same year completed the iLife suite.[Mac OS X, based on NeXT's OPENSTEP and BSD Unix was released on March 24, 2001, after several years of development. Aimed at consumers and professionals alike, Mac OS X aimed to combine the stability, reliability and security of Unix with the ease of use afforded by an overhauled user interface. To aid users in migrating from Mac OS 9, the new operating system allowed the use of OS 9 applications through Mac OS X's Classic environment.
On May 19, 2001, Apple opened the first official Apple Retail Stores in Virginia and California. The same year, Apple introduced the iPod portable digital audio player. The product was phenomenally successful — over 100 million units were sold within six years. In 2003, Apple's iTunes Store was introduced, offering online music downloads for $0.99 a song and integration with the iPod. The service quickly became the market leader in online music services, with over 5 billion downloads by June 19, 2008Since 2001 Apple's design team has progressively abandoned the use of translucent colored plastics first used in the iMac G3. This began with the titanium PowerBook and was followed by the white polycarbonate iBook and the flat-panel iMac2005–2007: The Intel transition
At the Worldwide Developers Conference keynote address on June 6, 2005, Steve Jobs announced that Apple would begin producing Intel-based Mac computers in 2006. On January 10, 2006, the new MacBook Pro and iMac became the first Apple computers to use Intel's Core Duo CPU. By August 7, 2006 Apple had transitioned the entire Mac product line to Intel chips, over 1 year sooner than announced. The Power Mac, iBook, and PowerBook brands were retired during the transition; the Mac Pro, MacBook, and MacBook Pro became their respective successors. On April 29, 2009, The Wall Street Journal reported that Apple was building its own team of engineers to design microchips.

Apple also introduced Boot Camp to help users install Windows XP or Windows Vista on their Intel Macs alongside Mac OS X.
Apple's success during this period was evident in its stock price. Between early 2003 and 2006, the price of Apple's stock increased more than tenfold, from around $6 per share (split-adjusted) to over $80. In January 2006, Apple's market cap surpassed that of Dell. Nine years prior, Dell's CEO Michael Dell said that if he ran Apple he would "shut it down and give the money back to the shareholders."
Although Apple's market share in computers has grown, it remains far behind competitors using Microsoft Windows, with only about 8 percent of desktops and laptops in the U.S.
2007–present: Mobile Consumer Electronics EraDelivering his keynote at the Macworld Expo on January 9, 2007, Jobs announced that Apple Computer, Inc. would from that point on be known as Apple Inc. because computers are just one part of the company now. This change reflects the company's focus to mobile electronic devices from personal computers. The event also saw the announcement of the iPhone and the Apple TV.The following day, Apple shares hit $97.80, an all-time high at that point. In May, Apple's share price passed the $100 mark.
In an article posted on Apple's website on February 6, 2007, Steve Jobs wrote that Apple would be willing to sell music on the iTunes Store without DRM (which would allow tracks to be played on third-party players) if record labels would agree to drop the technology. On April 2, 2007, Apple and EMI jointly announced the removal of DRM technology from EMI's catalog in the iTunes Store, effective in May. Other record labels followed suit later that year.
In July of the following year, Apple launched the App Store to sell third-party applications for the iPhone and iPod Touch. Within a month, the store sold 60 million applications and brought in $1 million daily on average, with Jobs speculating that the App Store could become a billion-dollar business for Apple. Three months later, it was announced that Apple had become the third-largest mobile handset supplier in the world due to the popularity of the iPhone.
On December 16, 2008, Apple announced that after over 20 years of attending Macworld, 2009 would be the last year Apple would be attending the Macworld Expo, and that Phil Schiller would deliver the 2009 keynote in lieu of the expected Jobs. Almost exactly one month later, on January 14, 2009, an internal Apple memo from Jobs announced that he would be taking a six-month leave of absence, until the end of June 2009, to allow him to better focus on his health and to allow the company to better focus on its products with out having the rampant media speculating about his health.[89] Despite Jobs' absence, Apple recorded its best non-holiday quarter (Q1 FY 2009) during the recession with a revenue of $8.16 billion and a profit of $1.21 billion.
After years of speculation and multiple rumored "leaks" Apple announced a large screen, tablet-like media device known as the iPad on January 27, 2010. The iPad runs the same touch based operating system that the iPhone uses and many of the same iPhone apps are compatible with the iPad. This gave the iPad a large app catalog on launch even with very little development time before the release. Later that year on April 3, 2010, the iPad was launched in the US and sold more than 300,000 units on that day and reaching 500,000 by the end of the first week
Current productsMac mini, consumer sub-desktop computer and server introduced in January 2005. iMac, consumer all-in-one desktop computer that was first introduced by Apple in 1998. Its popularity helped revive the company's fortunes. Mac Pro, workstation-class desktop computer introduced in August 2006. It replaced the Power Macintosh. MacBook, consumer notebook introduced in 2006. It replaced the iBook. MacBook Air, ultra-thin, ultra-portable notebook, introduced in January 2008. MacBook Pro, professional portable computer alternative to the MacBook, available in 13, 15, and 17-inch variants, introduced in January 2006. It replaced the PowerBook. Xserve, rack mounted, dual or quad core, dual processor 1U server. Apple sells a variety of computer accessories for Mac computers including the AirPort wireless networking products, Time Capsule, Cinema Display, Magic Mouse, the Apple Wireless Keyboard computer keyboard, and the Apple USB Modem.

iPadOn January 27, 2010, Apple introduced their much-anticipated media tablet, the iPad running a modified version of iOS. It offers multitouch interaction with multimedia formats including newspapers, magazines, ebooks, textbooks, photos, movies, TV shows videos, music, word processing documents, spreadsheets, video games, and all existing iPhone apps.[92] It also includes a mobile version of Safari for internet browsing, as well as access to the App Store, iTunes Library, iBooks store, contacts, and notepad. Content is downloadable via WIFI and optional 3G service or synced through the user's computer. AT&T is currently the sole US provider of 3G wireless access for the iPad.
Computer Modern is the family of typefaces used by default by the typesetting program TeX. It was created by Donald Knuth with his METAFONT program, and was most recently updated in 1992. However, the family font was superseded by CM-Super (Computer Modern-super), the latest release dating 2002. The latter was complemented by CM-LGC, which provides support for Latin, Greek and Cyrillic, with the latest release dating 2005. Both CM-Super and CM-LGC are included in TeXLive, a modern TeX distribution.

The Computer Modern typefaces are described in great detail (including full source code) in the book Computer Modern Typefaces, volume E in the Computers and Typesetting series, which is unique in the history of font design: in Knuth's words, they "belong to the class of sets of books that describe precisely their own appearance."

As implied by the name, Computer Modern is a modern font. Modern, or "Didone", fonts have high contrast between thick and thin elements, and their axis of "stress" or thickening is perfectly vertical. Computer Modern, specifically, is based on Monotype Modern 8a, and like its immediate model it has a large x-height relative to the length of ascenders and descenders.
The most unusual characteristic of Computer Modern, however, is the fact that it is a complete type family designed with the METAFONT system. The Computer Modern source files are governed by 62 distinct parameters, controlling the widths and heights of various elements, the presence of serifs or old-style numerals, whether dots such as the dot on the "i" are square or rounded, and the degree of "superness" in the bowls of lowercase letters such as "g" and "o". Computer Modern is by no means the only METAFONT-designed typeface, but it is by far the most mature and widely used.
The advance of printer technology has reduced the need for software rasterizers like METAFONT. Outline fonts (to be rendered by the printer or display system) are now generally preferred. As a result, many users have now migrated to Postscript-based replacements, mostly Type 1 implementation of Computer Modern, maintained by the American Mathematical Society, or Latin Modern, instead of the original METAFONT-based Computer Modern. The Latin Modern implementation, now standard in the TeX community, was made through a METAFONT/MetaPost derivative called METATYPE1.