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de:Acorn fr:Acorn sv:Acorn Acorn Computers Ltd. was a computer company founded in 1978 by Hermann Hauser in Cambridge, England. Later, Chris Curry joined Acorn from their Cambridge rivals Science of Cambridge, and they produced a number of computer models over the next decade and would go on to create their own CPU before Olivetti took control of the company in 1985. Acorn continued to produce new computer models as a subsidiary of Olivetti until about 1996. In 1998 they abandoned the desktop market and renamed themselves Element 14 (not coincidentally the atomic number of silicon). Then, in 1999, the microcomputer division was acquired by Pace and the DSP division was subject to a management buy-out. The DSP division continued to be known as Element 14 before being purchased by Broadcom in 2000 for $594 million.
Early computers 1979–80Between 1979 and 1980 Acorn launched a number of MOS Technology 6502 based computers named System 1 (or System One) through System 5.
The Acorn System 1 (http://www.cary.demon.co.uk/acorn/) (originally known simply as the Acorn Microcomputer) was designed by Sophie Wilson. It was a very small machine built on two cards, one (shown right) with an LED display, keypad, and cassette interface (the circuitry to the left of the keypad), and the other with the rest of the computer (including the CPU). Almost all CPU signals were accessible via a Eurocard connector. The System 2 made it easier to expand the system, by putting the CPU card from the System 1 in a 19" Eurocard rack which allowed a number of optional additions. The System 2 typically shipped with keyboard controller, and external keyboard, a text display interface, and a cassette operating system with built-in BASIC interpreter. The System 3 added floppy disk support, and the System 4 added a larger case with a second drive. The System 5 was largely similar to the System 4, but included a newer 2MHz version of the 6502. The Atom, Proton, and ElectronIn 1980 the engineers at Acorn took the internals of the System 3 and placed them inside the case of an external keyboard, creating a quite typical setup for an inexpensive home computer of the early 80s era — this one the relatively successful Acorn Atom. Work started almost immediately on a newer version of the Atom known as the Proton with better graphics, extensive expansion abilities, and the 2MHz 6502. as in the System 5. In early 1980, the BBC Further Education department conceived the idea of a computer literacy programme, mostly as a follow-up to a BBC documentary, The Mighty Micro, in which Dr. Christopher Evans from the UK National Physical Laboratory predicted the coming (micro)computer revolution. It was a very influential documentary — so much so that questions were asked in parliament. BBC Engineering was instructed to attempt to draw up an objective specification for a computer to accompany the series. As a result of the questions in Parliament, the Department of Industry (DoI) became interested in the programme, as did BBC Enterprises, who saw an opportunity to sell a machine to go with the series. Eventually, under some pressure from the DoI to choose a British system, the BBC chose the Grundy NewBrain. Although the NewBrain was under heavy development by Newbury, it soon became clear that Newbury was not going to be able to produce it. The BBC's programmes, initially scheduled for Autumn 1981, were moved back to Spring 1982. After Chris Curry and Clive Sinclair found out about the BBC's plans, the BBC allowed other manufacturers to submit their proposals. The BBC awarded Acorn the contract after seeing the prototype Proton (as well as lesser offerings from other vendors), and the machine was renamed the BBC Micro in November 1981. The BBC Micro was sold on the back of the BBC's computer literacy TV series The Computer Programme, in which it was used to demonstrate the various aspects of computing to the British public. During the next five years, a number of variants of the same design were launched, including the Acorn Electron, the BBC Model B+ and the BBC Master in several models. The Tube®With the Atom on the market, Acorn began to think about what was needed to replace it. There were new 16-bit processors coming onto the market - should they move in that direction? After a great deal of discussion, Hauser suggested a compromise - an improved 6502-based machine with far greater expansion capabilities. One of the proposed developments was the Tube. The Tube was to be a proprietary interface that would allow the Proton (BBC Micro) to be expanded by the addition of a second processor. In general, processing would be farmed out to the second processor leaving the host to perform I/O. Acorn sold a 6502 second processor for the BBC Micro. Torch Computer also developed a Z80 second processor and then launched their own range of CP/M computers using the BBC Micro motherboard as an I/O subsystem. Torch also produced a 68000 second processor. The Tube played an important role in the development of the Acorn RISC Machine processor since it was by developing the second processors that Acorn engineers were able to assess the performance of the various CPU options. The Acorn Business Computer (ABC)The IBM PC was launched on August 12 1981. Although a version of that machine was aimed at the enthusiast market much like the BBC Micro, its real area of success was business. The successor to the PC, the XT (EXtended Technology) was introduced in early 1983. The success of these machines, and the variety of Z80-based CP/M machines, in the business sector (and that sector's ability to cope with premium prices) demonstrated that it was a viable market - the development of a business machine looked like a good idea to Acorn. The Acorn Business Computer range was announced in 1984. The concept was to use the BBC Micro with a range of second processors operating over the Tube - Z80 for CP/M, 80286 running various versions of DOS, a 32016 running PANOS. The 32016-based machine was later marketed in small numbers as the Cambridge Workstation while the ABC range quietly died. 1984 was also the year in which the Apple Macintosh was launched. Using what was essentially a BBC micro as the graphics controller was now obviously a blind alley. The ARM architectureEven from the time of the Atom Acorn were considering how to move on from the 6502. The 16-bit Acorn Communicator was developed in 1982 using the 65816. The ABC range, although never launched, led to the development of a number of second processors for the BBC. In developing these second processor options for the BBC Micro and the ABC, Acorn had to implement the Tube protocols on each of the processor options chosen - finding out during 1983 that there were no obvious candidates to replace the 6502; for example, because of many-cycle uninterruptible instructions, the interrupt response times of the 68000 were too slow to handle the communication protocol that the host 6502-based BBC Micro coped with easily. Development of the Cambridge Workstation (a National Semiconductor 32016 based survivor of the ABC range) had shown Sophie Wilson and Steve Furber the value of memory bandwidth. It also showed that an 8MHz 32016 was completely trounced in performance terms by a 4MHz 6502. Furthermore, the Apple Lisa had shown the Acorn engineers that they needed to develop a windowing system - and this was not going to be easy with a 2-4MHz 6502-based system doing the graphics! The BBC Micro had been superbly optimised to display text - its video RAM was organised in such a way that putting an 8x8 bitmap of a text character onto the screen was calculation-lite and therefore fast. Now the world was becoming graphical... Acorn had tested all of the available processors and found them wanting. And when you have excluded the impossible, whatever remains, however improbable, must be the truth! Acorn needed to design its own processor. Acorn’s engineers came across papers on the Berkeley RISC project. They could now handle the truth - if a class of graduate students could create a competitive 32-bit processor, Acorn would have no problem! A trip to the Western Design Center in Phoenix showed Furber and Wilson that they didn't need massive resources and state-of-the-art R&D facilities. Sophie Wilson set about developing the instruction set, writing a simulation of the processor in BBC Basic that ran on a BBC Micro with a 6502 second processor. It convinced the Acorn engineers that they were on the right track... but before they could go any further they would need more resources. It was time for Wilson to approach Hauser and explain what was afoot. Once the go-ahead had been given, a small team was put together to implement Wilson's model in hardware. Work started in October 1983 and VLSI Technology produced the first silicon on 26 April 1985. It worked first time. The first use of ARM1 was as a second processor to the beeb and this system was then used to develop the simulation software to finish work on the support chips (VIDC, IOC, MEMC). Wilson subsequently coded BBC Basic in ARM assembly language and the in-depth knowledge obtained from designing the instruction set allowed the code to be very dense (a typical Wilson trait), making ARM BBC Basic an extremely good test for any ARM emulator. Such was the secrecy surrounding this project that when Olivetti took a controlling share of Acorn in 1985 they were not told about the development team until after the negotiations had been finalised. The Advanced Research and Development section of Acorn that had developed the processor formed the basis of ARM Ltd when that company was spun off. The first ARM-based product was the ARM Development System, a Tube-linked second processor for the BBC Master which allowed one to write programs for the new system. It cost around £4,000 to buy, and included the ARM processor and three support chips, 4MB of RAM and a set of development tools with an enhanced version of BBC BASIC. The Archimedes and Risc PCThe second ARM-based product was the Acorn Archimedes desktop-computer, released in mid-1987. The Archimedes was popular in the United Kingdom, Australasia and Ireland, and was considerably more powerful and advanced than most offerings of the day, but the market was already stratifying into the PC dominated world. Acorn continued to produce updated models of the Archimedes including a laptop (the A4) and the Risc PC where the top specification included a 200MHz+ StrongARM processor. These were sold mainly into education, specialist and enthusiast markets until Acorn finally abandoned producing desktop-computers in late 1998 in favour of set-top boxes. The last machine (codenamed "Phoebe" or Risc PC 2) was nearly fully developed at the time of the project's abandonment, and therefore was never produced in volume nor sold to the public (notably, numbers of its distinctive yellow case were produced and sold-off cheaply). The operating system developed for Phoebe (codename Ursula or RISC OS 4) was made available to Risc PC users by RISCOS Ltd, which licensed the operating system, and continues to develop, support and sell RISC OS today. However, the market is still competive with two strands of the OS currently being developed, the 26bit RISC OS 4 which is currently sold for the Microdigital Omega, and the 32bit RISC OS 5 for the Castle Iyonix. This competition recently caused a crisis in the community, one that threatened the platforms existence. Oracle and The Network ComputerIn August 1996 Acorn launched the network computer, a diskless device which implemented Oracle's Network Computer Reference Profile. The operating system was strongly based on Risc OS These machines were Larry Ellison's view of the future of computing through the internet.
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