As the Raspberry Pi edges closer to becoming the best-selling British computer of all time we take a look at the classic machines to come out of the UK.

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The Raspberry Pi has become one of the best-selling British computers of all time.

With more than five million of the credit-card sized computers out the door, the £35 board has moved closer to snatching sales crown from the Amstrad PCW, which shifted eight million units during the 1980s and 90s.

But just what sort of competition was the Pi up against? TechRepublic takes a look the gems produced by the British computer industry since the country's computing boom three decades ago.

To see a gallery of these classic British computers visit this article.

Acorn Atom

Cambridge-based Acorn introduced its first home computer, the Atom, for an affordable £120 if you were willing to build it from a kit, £170 if not.

The machine came with 2KB of RAM and 8KB of ROM, optional colour graphics, support for the Basic programming language, and a proper keyboard. A disk drive was also available for the machine but cost twice the price of the computer.

The Atom was launched in 1980 and sold until it was superseded by the Acorn Electron in 1983.

Acorn BBC Micro

A hit in the 1980s, this is the PC that inspired Pi co-creator Eben Upton to learn about computers when he was a child.

A total of 1.5 million machines were sold, with the PC adopted by most schools in the UK and enjoying moderate popularity among home users.

The BBC Micro booted directly to a command prompt where users could start programming in Basic, and was sold alongside guides that would walk you through writing your first programs. It was also extremely expandable, with room for additional language ROMs, an interface for second processors and other add-ons.

The original model A and B Micro featured a 2MHz 8-bit processor, a MOS 6502, and came with 16KB to 32KB of memory. The model A cost from £235 when it launched in 1981, about £880 in today's money. When you think the Raspberry Pi has just launched with a processor clocked at 500 times the speed for a measly £35, it demonstrates how much more powerful computers have become.

Sinclair ZX Spectrum

Similar to the Commodore 64 in the US, the Sinclair ZX Spectrum was many people's first taste of home computing.

Launched in 1982, the low price of £125 - some way below that of the BBC Micro and Commodore 64 - was at the heart of its appeal. The compact, boxy machine with it distinctive rubber keys became hugely popular, selling five million units in its lifetime - a record that has only just been beaten by the Raspberry Pi.

As sales grew, so did its software and today there are more than 20,000 Spectrum titles available spanning office programs, databases, drawing packages and a lot of games.

Inside the machine was an 8-bit Zilog Z80 processor, 16KB or 48KB of RAM and 16KB of ROM. Graphics wise it could support a 256 x 192 resolution display of up to eight colours and software ran from tapes or floppy discs.

Its unpredictable behaviour led to some of the machine's eccentricity and charm, with owners recalling having to set the volume just right for games to load from tape.

It was officially discontinued in 1992, but today there are a swathe of Spectrum emulators that allow past owners to relive their youth.

Acorn Electron

The Electron was a lightweight, less expensive version BBC Micro, designed to compete with the ZX Spectrum that was dominating the home PC market in the UK.

Unfortunately for the Electron the sacrifices made to get the price down to £175 limited its appeal, with games reported to run at less than half the speed of the BBC Micro. While most of the circuitry from a Model B was put into one ASIC (Application-specific integrated circuit), space and cost constraints meant that sound and video didn't match the original.

Launched in 1983, it stopped being made in 1985, when retailer Dixons bought the remaining stock of the ailing machine for less than the price of manufacture.

Grundy NewBrain

The Grundy NewBrain might not have been a hit among home users, but was moderately popular among science labs.

At one point the machine was destined to be the BBC-branded computer to accompany its TV series on computer literacy, although eventually the Acorn computers were chosen to make the BBC Micro in its place.

Priced at £199 for the most basic model, the unit was released in 1982 and ran a 4MHz Zilog 80A and had 24KB of RAM. While the model A had to output its display to a TV or monitor the model AD also had a one line, 16 character fluorescent display built into the keyboard.

It found favour with scientific researchers due to its strength at floating point computations and high-resolution graphics, able to drive 640×256 resolution displays.

Jupiter Ace

With a similar appearance and price to the ZX80 Spectrum, the Jupiter ACE superficially appeared primed for success in the early 1980s.

The ace up this machine's sleeve was its speed, despite using the same Zilog Z80 processor as the Spectrum and having it clocked to a lower frequency, it was able to outpace its rival in benchmarks - an advantage put down to its support for the Forth software language rather than the more popular Basic.

At a time when machines generally shipped with 16 - 32KB of memory the Ace also packed just 3KB and only 1KB of which was reserved for general use, again a symptom of Forth needing less memory to run programs than Basic did.

However the machine suffered from a lack of third-party software, which stopped sales from taking off, and Jupiter Cantab was wound up by November 1983, just 14 months after the machine had been announced.

Dragon 32 and 64

Built to capitalise on the home computer boom in the 1980s, the Dragon 32 and 64 initially sold well.

Produced in the Welsh town Port Tablot in Wales, the machine suffered from limitations that made it less attractive in comparison to other machines. The Dragon came with 32 or 64KB of memory and was built around the Motorola MC6809E processor, running at 0.89 MHz, an 8-bit CPU with limited 16-bit capabilities that in many respects outperformed competitors based on the MOS Technology 6502 CPUs.

However the machine's graphics processor struggled with many popular games and memory limitations meant it was unable to easily display lower-case letters, restricting its appeal to schools.

Eventually the machine was discontinued in 1984, two years after launch.

Memotech MTX500

Described as being aimed at the "serious home user and the business market", the Memotech MTX500 was praised for its looks and quality of its finish.

Released in 1983, the MTX 500 had a 4MHz Zilog Z80 A CPU, 32KB of RAM and was capable of driving a display with a resolution of up to 256 x 192 with 16 colours.

Like so many other machines the MTX range was hurt by a slump in PC sales in 1984, with the £275 machine struggling to displace the pricier BBC Micro Model B and the cheaper but less fully featured ZX Spectrum. By 1985 Memotech had dropped the price of the machine to £79.95 in an attempt to shift units, but it wasn't enough and the company went into receivership that year.

Camputer Lynx

Though in many ways a better machine than its competitors the Camputer Lynx was relatively short-lived.

Produced in earnest from 1983 onwards, the machine had a number of standout features, such as driving what were then relatively high resolution 256 x 248 graphics with eight colours on the screen at the same time.

The machine ran on a Z80A CPU clocked at 4 MHz, had from 48KB of RAM and a Motorola 6845 as video controller, with an optional 5.25" floppy disk-drive available for higher specced models.

The base machine sold for £225 and was praised for being competitive with the BBC Model B, which cost twice as much at the time.

Little software was produced for the machine during its short life and despite the machine being relaunched and rebranded Camputer went out of business in 1984, with an estimated 30,000 Lynxes having been produced.

Oric

The Oric-1 and Oric Atmos were produced by Cambridgeshire-based Tangerine Computer Systems.

Launched in 1983, the Oric-1 had a 1MHz processor and up to 48KB of memory. Its £129 price tag matched the pricing of models of the competing ZX Spectrum.

The Atmos model added a keyboard with full-sized individual keys and an updated V1.1 ROM.

Apricot Portable

Featuring a graphical interface reminiscent of a Mac, the Apricot Portable was released in November 1984.

The tiny machine packed in a 3.5-inch floppy drive, 4.77MHz CPU and 256KB of memory.

As well as having an 80-column / 25 line LCD screen, it was also one of the first to use speech recognition, able to detect 64 words at any one time.

The keyboard could link to the computer via an infrared beam, another novelty in the mid-1980s.

These then advanced features added up to a fairly pricey machine, sold at £1965 at launch.

Amstrad Colour Personal Computer

The low price of the Amstrad CPC (Colour Personal Computer), combined with its power and flexibility led to about three million machines being sold, making it one of the most successful series of computers in Europe.

Pitched as a rival to Commodore 64 and Sinclair ZX Spectrum, the CPC 464 with its 8-bit 4MHz and 64KB memory cost about £249 on its launch in 1984.

The variety of software the machine could run made it popular, from a large catalogue of games to CP/M software for business users.

The computer sat inside the keyboard, which also included an integrated tape recorder or floppy disc drive and storage. The machine was bundled with a colour or monochrome monitor and a range of peripherals such as printers and drives could be bought as extras. Users could chose from several display resolution, ranging from 160×200 pixels with 16 colours to 640×200 pixels with two colours.

Enterprise

The machine had several monikers before settling on the Enterprise, going by the sprightly Elan and the rather less flattering Flan.

Launched in 1985 for £228, the Enterprise had a 4 megahertz (MHz) Zilog Z80 CPU, 64 kB or 128 kB of RAM. Capable of better overall performance than many competing machines at the time, it created a buzz at the time for it's futuristic look and the bold primary colours of its keyboard and integrated joystick.

However, the machine , developed by British firm Intelligent Software, was also criticised for arriving too late, and it struggled to make an impact in a market already dominated by Amstrad, Commodore and Acorn machines.

The fondness for quirky names extended to its electronics, with the video chip named "Nick" and sound processor named "Dave", after their designers Nick Toop and Dave Woodfield.

RM Nimbus

The Research Machines (RM) Nimbus PC was a relatively nippy machine at the time of its release in 1985.

Despite its comparatively decent specs, packing an Intel 80186 processor, 192KB of RAM and a single floppy disk drive, it had a limited ability to run software.

It ran a modified version of the then popular operating system MS-DOS and, without the use of an emulator, could not run much of the software that worked on other IBM-compatible machines.

The PC, which was designed to be used in schools and colleges, could be expanded to 1MB of RAM and to 160MB of hard disk space. RM later released Intel 286, 386 and 486-based versions of the PC.

Acorn Archimedes

One of the most powerful home computers available during the late 1980s, the Archimedes was Acorn's first home computer based on its ARM architecture - now found in the majority of the world's smartphones.

Despite racking up faster benchmarks than the Commodore Amiga and Atari ST machines popular at the time, the machine was more often found in schools than in homes.

The base machine - the Archimedes 305 came with 512KB of memory, and a single core ARM2-based processor when it launched in 1987 at a price of £799.

Archimedes machines with varying specs were made through to 1992, but from the early 1990s schools began to adopt Apple Macintosh and IBM-compatible PCs instead, leading to the decline in Archimedes use.

RiscPC

The successor to the Archimedes, the RiscPC was a marked upgrade over its predecessor upon its release in 1994.

With a 30MHz ARM 610 CPU based on a new processor architecture, general performance was noticeably better than that of the most powerful Archimedes.

Improvements were made across the board, with a video chip that could display 16-million colours, compared to the 256 maximum of earlier Acorn machines, and support for 8-channel, 16-bit stereo sound in later models.

Risc PCs also allowed a non-ARM CPU to be used as a guest processor, which let Windows PC programs run on the computer.

Not a cheap option, the Risc PC 600 was priced from £1249. It shipped with the Risc OS, an operating system that still runs on the Raspberry Pi today.