Acorn Archimedes

The Acorn Archimedes is a family of personal computers designed by Acorn Computers of Cambridge, England. The systems were based on Acorn's own ARM architecture processors and the proprietary operating systems Arthur and RISC OS. The first models were introduced in 1987, and systems in the Archimedes family were sold until the mid-1990s.
ARM's RISC design, a 32-bit CPU (using 26-bit addressing), running at 8 MHz, was stated as achieving 4.5+ MIPS, which provided a significant upgrade from 8-bit home computers, such as Acorn's previous machines. Claims of being the fastest micro in the world and running at 18 MIPS were also made during tests.
Two of the first models - the A305 and A310 - were given the BBC branding, with BBC Enterprises regarding the machines as "a continuing part of the original computer literacy project". Dissatisfaction with the branding arrangement was voiced by competitor Research Machines and an industry group led by a Microsoft representative, the British Micro Federation, who advocated the use of "business standard" operating systems such as MS-DOS. Responding to claims that the BBC branding was "unethical" and "damaging", a BBC Enterprises representative claimed that, with regard to the BBC's ongoing computer literacy initiatives, bringing in "something totally new would be irresponsible".
However, the name "Acorn Archimedes" is commonly used to describe any of Acorn's contemporary designs based on the same architecture. This architecture can be broadly characterised as involving the ARM CPU and the first generation chipset consisting of MEMC (MEMory Controller), VIDC (VIDeo and sound Controller) and IOC (Input Output Controller).
History.
Having introduced the BBC Micro in 1981, Acorn had established itself as a major supplier to primary and secondary education in the United Kingdom. Attempts to reproduce the same dominance in other sectors, such as in home computing with the BBC Micro and Acorn Electron, and in other markets, such as the United States and West Germany, had been rather less successful. With microprocessor and computing technology making considerable advances in the early 1980s, microcomputer manufacturers were obliged to consider the evolution of their product lines to provide increasing capabilities and performance. Acorn's strategy for business computing and for introducing more capable machines involved a range of "second processor" expansions, with a Z80 second processor running the CP/M operating system being a product to which Acorn had committed when securing the BBC Micro contract.
Meanwhile, established platforms such as CP/M running on Z80 processors were being challenged by the introduction of the IBM PC running PC DOS and computers running a variety of operating systems on Intel processors such as the 8088 and 8086. Systems using the Motorola 68000 and other processors running the Unix operating system were also becoming available. Drawing on previous work by Xerox, Apple had launched the Lisa and Macintosh computers, and Digital Research had introduced its own GEM graphical user interface software.
Acorn's strategy ostensibly evolved to follow the lead of Torch Computers - the subject of an uncompleted acquisition by Acorn - who had already combined BBC Micro hardware with second processors (and modems) to produce their Communicator product line and the Torch 725. In 1984, Acorn presented the Acorn Business Computer (ABC) range, building around the BBC Micro architecture and offering models with different second processors and capabilities, thus responding to and anticipating the current and future trends in computing at the time. These models were tentatively favourably received by the computing press. However, with Acorn financially overstretched from its different endeavours, the company was rescued by Olivetti in 1985, with the future of the ABC range left uncertain in the anticipated rationalisation exercise that would follow. Ultimately, only one of the variants - the Acorn Cambridge Workstation - would reach the market, and in a somewhat different form to that originally planned.
The demise of the Acorn Business Computer left Acorn purely with a range of 8-bit microcomputer products, leaving the company vulnerable to competitors introducing 16-bit and 32-bit machines. The increasing dominance of MS-DOS in the business market and advocacy for the use of such software in the education sector left Acorn at risk of potential exclusion from its core market. Acorn's ability to respond convincingly to these competitive threats was evidently constrained: the BBC Model B+ was merely a redesigned BBC Model B (with some heritage in the ABC endeavour) providing some extra memory but costing more than its predecessor, being labelled as a "stop gap" by Acorn User's technical editor, expressing frustration at opportunities not taken for cost reduction and at a general lack of technological innovation in that "Acorn has never shown interest in anything as exciting as the 68000". Disillusionment was sufficient for some software producers to signal a withdrawal from the Acorn market.
Other commentators in response to the B+ suggested that Acorn pursue the second processor strategy more aggressively, leveraging the existing user base of the BBC Micro while those users were still using the machine. In 1986, Acorn introduced the BBC Master series, starting with the Master 128 which re-emphasised second processors in the form of internally fitted "co-processors". Although a modest evolution of the existing 6502-based platform, enthusiasm for the series was somewhat greater than that for the B+ models, with dealers and software developers citing the expansion capabilities and improved compatibility over the B+. However, the competitiveness of these co-processors proved to be constrained by hardware limitations, compatibility and pricing, with a Master 512 system featuring a Master 128 and 80186 co-processor comparing unfavourably to complete IBM PC-compatible systems. The planned Master Scientific product was never launched, leaving potential customers with the existing Cambridge Co-Processor expansion as their only available option.
Attitudes towards Acorn and its technological position changed somewhat in late 1985 as news of its RISC microprocessor development effort emerged, potentially encouraging Olivetti to continue its support for the company at "a critical stage" in its refinancing of Acorn. Subsequent commentary suggested the availability of this microprocessor - the Acorn RISC Machine - in future computers as well as in an evaluation board for the BBC Micro, although such a board - the ARM Evaluation System - would only be announced in mid-1986 at a cost of £4500. Having also developed the additional support chips required to make up a complete microcomputer, Acorn was regarded as having leapt ahead of its nearest competitors.
On the eve of the announcement of Acorn's 32-bit ARM-based microcomputer products, prototypes designated A1 and A500 were demonstrated on the BBC television programme "Micro Live" exhibiting BASIC language performance ten times faster than a newly introduced 80386-based computer from perennial education sector rival Research Machines, with suggestions made that the machines would carry the BBC branding. Revealingly, Acorn's managing director noted, "Over the past two years we've paid the price of having no 16-bit micro."
A300 and A400 series.
The Acorn Archimedes was variously described as "the first RISC machine inexpensive enough for home use" and "the first commercially-available RISC-based microcomputer". The first models were released in June 1987, as the 300 and 400 series. The 400 series included four expansion slots (although a two slot backplane could be added to the 300 series as an official upgrade, and third parties produced their own 4-slot backplanes) and an ST-506 controller for an internal hard drive. Both models included the Arthur operating system (later replaced by RISC OS as a paid-for upgrade), BBC BASIC programming language, and an emulator for Acorn's earlier BBC Micro, and were mounted in two-part cases with a small central unit, monitor on top, and a separate keyboard and three-button mouse (the middle one used for pop-up context menus of the operating system). All models featured eight-channel 8-bit stereo sound and were capable of displaying 256 colours on screen.
Three models were initially released with different amounts of memory, the A305, A310 and A440. These were replaced in 1989 with the A410/1, the A420/1 and A440/1, these featuring an upgraded MEMC1a and RISC OS. Earlier models which shipped with Arthur could be upgraded to by replacing the ROM chip containing the operating system. Because of the ROM chip containing the operating systems, the computer booted instantly into its GUI system, rare for its time.
A3000.
Speculation gathered pace about new machines in the Archimedes range in early 1989, with commentators envisaging a low-cost, cut-down model with 512 KB of RAM to replace the A305 in a fashion reminiscent of the Master Compact. Such speculation also raised questions about the 300 series if a low-cost model were to become available with support for up to 2 MB of RAM, given the limitations of the 300 series to a maximum of 1 MB (at least in terms of upgrade availability at the time), this potentially making the older models look "pretty stupid" according to one commentator. This speculation evolved to more accurately predict a machine with 1 MB of RAM aimed at junior or primary schools, albeit incorrectly predicting a separate disc drive unit.
Concurrently with these rumoured product development efforts, work had commenced on a successor to the Arthur operating system, initially named Arthur 2 but renamed to RISC OS 2 for launch. A number of new machines were introduced along with RISC OS 2, and in May 1989, the 300 series was phased out in favour of the new BBC A3000, with the 400 series being replaced by the improved 400/1 series models.
The A3000 used an 8 MHz ARM2 and was supplied with of RAM and RISC OS on of ROM. Unlike the previous models, the A3000 came in a single-part case similar to the BBC Micro, Amiga 500 and Atari ST computers, with the keyboard and disc drive integrated into a base unit "slightly smaller than the Master 128". Despite the machine's desktop footprint, being larger than a simple keyboard, the case was not designed to support a monitor. Acorn offered a monitor stand that attached to the machine, this being bundled with Acorn's Learning Curve package, and PRES announced a monitor plinth and external disc drive case.
The new model sported only a single internal expansion slot, which was physically different from that of the earlier models, although electrically similar. An external connector could interface to existing expansion cards, with an external case for such cards being recommended and anticipated at the machine's launch, and one such solution subsequently being provided by PRES's expansion system. Although only intended to be upgradeable to of RAM, third-party vendors offered upgrades to along with expansions offering additional disc drive connections and combinations of user and analogue ports, both of these helping those upgrading from Acorn's 8-bit products, particularly in education, to make use of existing peripherals such as 5.25-inch drives, input devices and data logging equipment. Hard drive expansions based on ST506, SCSI and IDE technologies were also offered by a range of vendors.
With the "British Broadcasting Corporation Computer System" branding, the "main market" for the A3000 was schools and education authorities, and the educational price of £529 - not considerably more expensive than the BBC Master - was considered to be competitive and persuasive in getting this particular audience to upgrade to Acorn's 32-bit systems. The retail price of £649 plus VAT was considered an "expensive alternative" to the intended competition - the Commodore Amiga and Atari ST - but many times faster than similarly priced models of those ranges. The Amiga 500, it was noted, cost a "not-so-bargain" £550 once upgraded to of RAM.
The relative affordability of the A3000 compared to the first Archimedes machines and the release of RISC OS helped to convince educational software producers of the viability of the platform. Shortly after the A3000's launch, one local education authority had already ordered 500 machines, aiming to introduce the A3000 to its primary schools in addition to other levels of education. Such was the success of the model that it alone had 37 percent of the UK schools market in a nine month period in 1991 and, by the end of that year, was estimated to represent 15 percent of the 500,000 or more computers installed in the country's schools.
The appeal of the A3000 to education may also have motivated the return of Microvitec to the Acorn market with the Cub3000 monitor: a re-engineered version of the Cub monitor that was popular amongst institutional users of the original BBC Micro. (Having been "nowhere to be seen" when the Archimedes was released, Microvitec had sought to introduce its own Cubpack range of IBM PC-compatible personal computers for the education market offering some BBC BASIC compatibility, building on an estimated 80 percent market share for 14-inch colour monitors in the sector, and aspiring to launch an "interactive video workstation".)
The introduction of the A3000 also saw Acorn regaining a presence in mainstream retail channels, with a deal with high street retailer Dixons to sell the computer at "business centre" outlets, followed by agreements with the John Lewis and Alders chains. Acorn also sought to secure the interest of games publishers, hosting a conference in August 1989 for representatives of "the top 30 software houses, including Ocean, Domark, US Gold, Grand Slam and Electronic Arts".
Marketing efforts towards home users continued in 1990 with the introduction of The Learning Curve: a bundle of A3000 and application software priced at £699 plus VAT, requiring a SCART capable television, or bundled with a colour monitor and Acorn's monitor stand for £949 plus VAT. The software, having a retail value of around £200, consisted of the second, RISC OS compliant version of Acorn's First Word Plus, the hypermedia application Genesis, and the PC Emulator software, with an introductory video presented by Fred Harris. Aiming at the "pre-Christmas market" in 1990, another bundle called Jet Set offered a more entertainment-focused collection of software valued at £200 including Clares' Interdictor flight simulator, Domark's Trivial Pursuit, Superior Golf, and the Euclid 3D modelling package from Ace Computing. The price of this bundle was £747.50 which also included a television modulator developed by the bundle's distributor, ZCL, designed for use with "any TV set" and offering a "monitor quality" picture.
A540.
The A540, introduced in late 1990, was an anticipated consequence of Acorn's Unix workstation development, offering the same general specification as Acorn's R260 Unix workstation (running RISC iX) but without built-in Ethernet support and running RISC OS 2 instead of Unix. It was Acorn's first machine to be fitted with the ARM3 processor as standard, supporting up to 16 MB of RAM, and included higher speed SCSI and provision for connecting genlock devices. The memory access frequency was raised to 12 MHz in the A540, compared to 8 MHz in earlier models, thus providing enhanced system performance over earlier models upgraded with ARM3 processors. The hardware design featured memory modules, each providing their own memory controller and 4 MB of RAM, and a processor module providing the ARM3 and a slot for a floating point accelerator (FPA) chip, the latter offering the possibility (subsequently unrealised) of processor upgrades. The FPA, replacing Acorn's previous floating point podule, was scheduled to be available in 1991. Much delayed, the FPA finally became available in 1993.
A5000 and A4 laptop.
In late 1991, the A5000 was launched to replace the A440/1 machine in the existing product range. With the existing A400/1 series regarded as "a little tired", being largely unchanged from the A400 models introduced four years previously, the A5000 was regarded (by one reviewer, at least) as "the biggest leap forward for Acorn since the introduction of the Archimedes in 1987", introducing a combination of the ARM3 processor and RISC OS 3 for the first time in a new Acorn product, being "the machine the A540 should have been - smaller, neater, with higher capacity drives and all the same speed for about half the cost".
The A5000 featured the new 25 MHz ARM3 processor, 2 or 4 MB of RAM, either a 40 MB or an 80 MB hard drive and a more conventional pizza box-style two-part case (HxWxD: 100 mm × 430 mm × 340 mm). With IBM-compatible PCs offering increasingly better graphical capabilities, they had not merely matched the capabilities of Acorn's machines, but in offering resolutions of 1024 x 768 in 16 or 256 colours and with 24-bit palettes, they had surpassed them. The A5000 (along with the earlier A540) supported the SVGA resolution of 800 x 600 in 16 colours, although the observation that "Archimedes machines have simply not kept pace" arguably remained.
It was the first Archimedes to feature a High Density capable floppy disc drive as standard. This natively supported various formats including DOS and Atari discs; RISC OS' own ADFS floppy format had a relatively large capacity of 800 KB for "double" (low) density or 1600 KB for high density. A later version of the A5000 featured a 33 MHz ARM3, 4 or 8 MB of RAM, an 80 or 120 MB hard drive.
The A5000 initially ran the new 3.0 version of RISC OS, although several bugs were identified; most were shipped with RISC OS 3.10 or 3.11. As before, earlier machines were capable of being upgraded to the new RISC OS 3, though some needed to have an additional daughterboard installed first. Earlier models could also benefit from the video performance of the A5000 via third party upgrades such as the Computer Concepts ColourCard Gold.
In 1992, Acorn introduced the A4 laptop computer featuring a slower 24 MHz (compared to the 25 MHz A5000) version of the ARM3 processor and a LCD screen capable of displaying a maximum resolution of in 15 levels of grey. However, it did feature a monitor port which offered the same display capabilities as an A5000. A notable omission from the machine was a built-in pointing device, requiring users to navigate with the cursor keys or attach a conventional Acorn three-button mouse.
A3010, A3020, A4000.
In 1992, several new models were introduced to replace the A3000 and low-end A400 series models - the A3010, A3020 and A4000 - thus starting a transition from a range of machines of different vintages that still included the A3000 (at the low end) and the A540 (at the high end) to a range that purely featured more recently designed models (including the A5000 as the high-end offering).
These new models utilised the first ARM system-on-chip: the ARM250 microprocessor, a single-chip design including the functionality of an ARM3 chip without cache, the IOC1, VIDC1a and MEMC1a chips all integrated into one chip. The increase in clock frequency, from 8 MHz to 12 MHz, gave a performance of 7 MIPS. The machines were supplied with RISC OS 3.10 or 3.11. The A30x0 series had a one-piece design, similar to the A3000 but slightly more shallow, while the A4000 looked like a slightly slimmer A5000. The A3010 model was intended to be a home computing machine, featuring a TV modulator and standard 9-pin joystick ports, while the A3020 targeted the home office and educational markets, featuring a built-in 2.5" hard drive and a dedicated network interface socket. Technically, the A4000 was almost identical to the A3020, only differing in hard disk size (3.5-inch in the A4000), though it sported a different appearance. All three ARM250-based machines could be upgraded to 4 MB with plug-in chips (though the A3010 was designed for 2 MB, third party upgrades overcame this) and one "mini-podule" slot as used for internal expansion in the A3000.
Later A-series models.
The "A7000", despite its name being reminiscent of the Archimedes naming conventions, was actually more similar to the Risc PC, the line of RISC OS computers that succeeded the Archimedes in 1994. It lacked, however, the DEBI expansion slots and multi-slice case that characterized the Risc PC (though by removing the CDROM, a backplane with one slot could be fitted).
Software.
Arthur operating system.
Reminiscent of the BBC Micro upon its release, the earliest Archimedes models were delivered with provisional versions of the Arthur operating system, for which upgrades were apparently issued free of charge, thus avoiding the controversy around early ROM upgrades for the BBC Micro. In early 1988, Arthur 1.2 was delivered in an attempt to fix the deficiencies and problems in the earlier versions of the software. However, even after Arthur 1.2 had been released, a reported 100 documented bugs regarded as "mostly quite obscure" persisted, with Acorn indicating that a "new, enhanced version" of the operating system was under development.
Early applications.
Following on from the release of Arthur 1.2, Acorn itself offered a "basic word processor", ArcWriter, intended for "personal correspondence, notices and short articles" and to demonstrate the window, menu and pointer features of the system, employing built-in printer fonts for rapid printed output. The software was issued free of charge for registered users, although Acorn indicated that it would not produce a "definitive" word processor for the platform, in contrast to the BBC Micro where the View word processor had been central to Acorn's office software range. However, Acorn did also announce a port of the 1st Word package, First Word Plus, for the platform. ArcWriter was poorly received, with window repainting issues demonstrated as a particular problem, and with users complaining of "serious bugs". Although taking advantage of the Arthur desktop environment and using anti-aliased fonts, complaints were made about "blurred and smudged" characters and slow display updates when changing fonts or styles on low-memory machines like the A305. An early competitor, Graphic Writer, was received more favourably but provided its own full-screen user interface. Neither were regarded as competitive with established products on other platforms.
Several software companies immediately promised software for the Archimedes, most notably Computer Concepts, Clares and Minerva, with Advanced Memory Systems, BBC Soft and Logotron being other familiar software publishers. Autodesk, Grafox and GST were newcomers to the Acorn market. However, in early 1988, many software developers were reportedly holding off on releasing software for the Archimedes until the release of a stable operating system, with Acorn offering to lend Arthur 1.2 to developers. Claims had been made of confusion amongst potential purchasers of the machine caused by the lack of available software, with Acorn having pursued a strategy of launching the machine first so that independent software developers might have hardware to work with. In order to make the Archimedes more attractive to certain sectors, Acorn announced a £250,000 investment in educational software and indicated a commitment to business software development. Alongside First Word Plus, the Logistix spreadsheet-based business planning package was also commissioned by Acorn from Grafox Limited as a port to the platform. Autodesk released AutoSketch for the Archimedes in 1988.
Although Acorn had restricted itself to supporting the use of its View word processor under BBC emulation on the Archimedes, View Professional - the final iteration of the View suite on Acorn's 8-bit computers - had been advertised as a future product in June 1987 for November availability. View Professional, like the View series, had been developed for Acorn by Mark Colton, and a company - Colton Software - delivered the successor to this product as Pipedream for the Cambridge Computer Z88. In mid-1988, Colton Software announced Pipedream for the Archimedes, priced at £114, following on from the announcement of a version for MS-DOS, establishing a long history of product development for the platform, leading to Pipedream 4 in 1992, followed by Pipedream's eventual successor, Fireworkz, in 1994.
Much early software had consisted of titles converted from the BBC Micro, taking advantage of a degree of compatibility between the different series of machines, with Computer Concepts even going as far as to produce a ROM/RAM hardware expansion for use with the company's existing BBC Micro series products, and Acorn also offering such an expansion alongside a BBC-compatible interfacing expansion. Another element of Acorn's early marketing strategy for the Archimedes was to emphasise the PC Emulator product which was a software-based emulator for IBM PC-compatible systems based on the 8088 processor running "legal MS-DOS programs". Alongside this, plans were also made for the launch of a podule (peripheral module) hardware expansion providing its own 80186 processor, a disk controller and connector for a disk drive. The podule expansion was subsequently postponed in early 1988 (and ultimately cancelled), with Acorn indicating that its price of £300 would have been uncompetitive against complete PC systems costing as little as £500, and that the hardware capabilities to be offered, such as the provision of CGA graphics, would be likely to become outdated as the industry moved to support EGA and VGA graphical standards.
Commentators were disappointed with the incoherent user interface provided by the software platform, with "Logistix looking like a PC, First Word slavishly copying GEM" and "101 other 'user interfaces'" amongst the early offerings. The result was the lack of a "personality" for the machine which risked becoming a system that would "never look as easy or as slick as the Mac". Alongside the introduction of visual and behavioural consistency between applications, personal computer user environments had also evolved from running a single application at a time, moved beyond "desk accessories" (or pop-up programs), normalised the practice of switching between applications, and had begun to provide the ability to run different applications at the same time, with the Macintosh having already done so with its MultiFinder enhancement. Computer Concepts, having begun development of various new applications for the Archimedes, was sufficiently frustrated with Arthur and its lack of "true multi-tasking" that it announced a rival operating system, Impulse, intended to host those applications on the machine.
RISC OS.
Remedying various criticisms of the early operating environment, Acorn previewed RISC OS in late 1988 and announced availability for April 1989. Reactions to the upgraded operating system were positive and even enthusiastic, describing RISC OS as giving software developers "the stable platform they have been waiting for" and "a viable alternative to the PC or Mac", also crediting Acorn for having improved on the original nine month effort in developing Arthur in the following twelve months leading up to the unveiling of RISC OS. For a modest upgrade cost of £29, users received four ROM chips, three discs including several applications, and documentation.
New facilities in RISC OS included co-operative multitasking, a task manager to monitor tasks and memory, versatile file management, "solid" window manipulation ("the whole window moves - not just the outline"), and adaptive rendering of bitmaps and colours, using dithering where necessary, depending on the nature of the selected screen mode. A common printing framework was introduced, with dot-matrix and PostScript printer drivers supplied, with such drivers available for use by all desktop applications. Amongst the selection of applications and tools included with RISC OS were the Draw graphics editor, featuring vector graphics editing and rudimentary manipulation of text (using the anti-aliased fonts familiar from Arthur) and bitmaps, the Edit text editor, the Paint bitmap editor, and the Maestro music editor.
With RISC OS available, Acorn launched new and updated applications to take advantage of the improved desktop environment. One of these, deferred until after the launch of RISC OS, was Acorn Desktop Publisher, a port of Timeworks Publisher, which introduced a significant improvement to the anti-aliased font capabilities through a new outline font manager, offering scalable fonts that were anti-aliased on screen but rendered at the appropriate resolution when printed, even on dot-matrix printers. First Word Plus was also updated to support the new RISC OS desktop environment, albeit retaining its own printer drivers, being positioned as complementing Acorn Desktop Publisher whose emphasis was on page layout as opposed to textual document creation.
As part of an effort to grow the company's share of the home market, Acorn introduced a bundle called The Learning Curve, initially featuring the A3000, optional monitor and a set of applications (First Word Plus, the PC Emulator, and Genesis). This bundle was enhanced later in 1990 to attract buyers to the A420/1, adding Acorn Desktop Publisher and some additional Genesis applications. Acorn's document processing applications also began to see broader competition around this time, with Impression from Computer Concepts and Ovation from Beebug also providing competitive solutions for desktop publishing. Also in 1990, Pipedream 3 became the first version of the Pipedream integrated suite, descended from Acorn's View Professional but developed and marketed by Colton Software, to be made available for the RISC OS desktop.
Art and image editing.
Having considerably improved graphical capabilities compared to those provided with Acorn's 8-bit machines, a number of art packages were released for the Archimedes to exploit this particular area of opportunity, albeit rather cautiously at first. One of the first available packages, Clares' Artisan, supported image editing at the high resolution of but only in the 16-colour mode 12, despite the availability of the 256-colour mode 15 as standard. Favourably received as being "streets ahead" of art software on the BBC Micro, it was considered as barely the start of any real exploitation of the machine's potential. Typical of software of the era, only months after the launch of the machine, Artisan provided its own graphical interface and, continuing the tradition of BBC Micro software, took over the machine entirely even to the point of editing the machine configuration and restoring it upon exiting. Clares released a successor, Artisan 2, two years later to provide compatibility with RISC OS, replacing special-purpose printer support with use of the system's printer drivers, but not making the software a desktop application. The program's user interface deficiencies were regarded as less forgivable with the availability of a common desktop interface that would have addressed such problems and made the program "easier to use and a more powerful program as a result".
Clares also produced a 256-colour package called ProArtisan, also with its own special user interface (despite the impending arrival of RISC OS), costing considerably more than its predecessor (£170, compared to £40 for Artisan), offering a wider range of tools than Artisan including sprays, washes and path editing (using Bezier curves) to define areas of the canvas. Although regarded as powerful, the pricing was considered rather high from the perspective of those more familiar with the 8-bit software market, and the user interface was regarded as "only just bearable". Competitors to ProArtisan during 1989 included Art Nouveau from Computer Assisted Learning and Atelier from Minerva. Both of these programs, like ProArtisan, ran in full-screen mode outside the desktop, used the 256-colour mode 15, and offered their own interfaces. Atelier, however, was able to multi-task, providing the ability to switch back to the desktop and find applications still running and accessible. Unlike other contemporary art programs, it also took advantage of the system's own anti-aliased fonts. One unusual feature was the ability to wrap areas of the canvas around solid objects. Both programs also offered similar path editing facilities to ProArtisan, with it being noted that Art Nouveau's limitations in this regard might be remedied by using the support already present in RISC OS and provided by the Draw application functionality, as ProArtisan 2 eventually demonstrated.
In 1989, RISC OS was provided with the Paint application on one of the accompanying application discs. It featured a multi-document, desktop-based interface with a range of elementary painting and drawing tools, also allowing images to be created in arbitrary sizes for any of the display modes, even permitting editing of images in display modes with different numbers of colours, albeit with limitations in the representation of image colours when the desktop mode had fewer colours available. Along with its companion applications, Paint supported the system's anti-aliased fonts and printer driver framework, and by embracing the system's user interface conventions, images could be exported directly to applications such as Draw by dragging an image's file icon from the save dialogue directly to the target application.
Despite a trend of gradual adoption of desktop functionality, in 1990, Arcol from ExpLAN offered a single-tasking, full-screen, 256-colour editing experience using the lower resolution mode 13, supporting only bitmap fonts. Aimed at educational users, its strengths apparently included real-time transformation of canvas areas, rapid zooming, and the absence of limitations on tools when zooming: arguably demonstrating more a limitation of contemporary packages with their own peculiar interfaces. ExpLAN subsequently released Arcol Desktop, although the "desktop" label only indicated that the program would multi-task with desktop applications and offer some desktop functionality, particularly for the loading and saving of images: the program still employed a special full-screen user interface, albeit allowing other 256-colour modes to be used, with the mode of the original being the default. With expectations having evolved with regard to user interfaces and desktop compatibility, this updated product was judged less favourably, with the partitioning of functionality between the desktop and painting interface being "awkward" and the behavioural differences "confusing", leaving the product looking "rather dated" when compared to its modern contemporaries.
In early 1991, in the context of remarks that, at that point in time, the Paint application bundled with RISC OS was "the only true Risc OS art program" operating in the desktop and not restricting users to specific display modes, Longman Logotron released Revelation, an application running in the desktop environment, providing interoperability with other applications through support for the platform's standard Sprite and Drawfile formats, with vector graphics import being provided by a companion tool, and utilising the system's printing framework. Apart from observations of limited functionality in some areas, one significant limitation reminiscent of earlier products was the inability to change display mode without affecting the picture being edited. This limitation was not convincingly removed in the second version, sold as Revelation 2 around a year later, with colours being redefined when selecting a 16-colour display mode while editing a 256-colour image, preserving the inability to edit 256-colour images in 16-colour modes. A further version update was delivered as the Revelation ImagePro product, being considered "the best art package that I have used on the Archimedes" by Acorn User's graphics columnist in late 1992.
In response to the evolving competitive situation and market expectations, Clares released ProArtisan 2, a successor to its earlier product, in late 1993 as "a completely new program" with some familiar features from the company's earlier products but offering display mode independence, 24-bit colour support (including support for ColourCard and G8/G16 graphics cards), multi-document editing, and desktop compliance. The path editing tools familiar from its predecessor were supported using functionality from Acorn's Draw application, and the image enhancement capabilities had also "undergone a major revamp". At a reduced price of £135, and with use of the RISC OS desktop contributing to overall ease of use, the package was considered by one reviewer as "the best art package around at the moment for the Archimedes".
Hardware.
Graphical capabilities.
The Archimedes machines (and their equivalents running RISC iX) used the VIDC1a video chip to provide a wide variety of screen resolutions, expanding on those available on the BBC Micro:
Since the video controller would not support display modes smaller than 20 KB, the lowest resolution modes were supported in the operating system by employing modes with twice the horizontal resolution and duplicating horizontally adjacent pixels.
The A540 and A5000 supported additional display modes:
High-resolution monochrome display modes were offered by the A440, A400/1 series and A540:
Apparent confusion about monochrome monitor support upon the launch of the Archimedes models led Acorn to clarify that the A400 series had "extra circuitry" offering two additional display modes "of up to 1280 by 976 in monochrome, and 160 columns by 122 lines of text, but only using a special monitor", this being connected using two BNC sockets (one for signal and one for sync).
The A540 (and corresponding R-series workstations) offered three BNC sockets, adding one for a separate horizontal sync connection for certain monitors. Acorn suggested the 19-inch Taxan Viking and Philips M19P114 monitors, with the former being offered in a bundle with the R140 workstation. The Taxan Viking R140 product bundled the existing Viking product with appropriate cabling and produced a "rock steady" 66 Hz mode 23 display, albeit with mouse pointer corruption at the extreme right of the screen due to "a bug in the VIDC chip".
The A5000 unlike its predecessor, the A540, did not support high resolution monochrome modes.
Graphics expansions.
An expansion to speed up the VIDC chip in the Archimedes from 24 MHz to 36 MHz was announced by Atomwide in 1990, offering higher resolution display modes for machines connected to multisync monitors. Although resolutions up to and were supported, flicker due to a decreased refresh rate was reported as a problem, with appearing to be more comfortable in this regard. The SVGA resolution of was also supported in up to 16 colours. One side-effect of increasing the frequency of the VIDC was to also increase the frequency of generated sounds, since the VIDC was also responsible for sound generation. VIDC enhancers were supplied by some monitor vendors together with the appropriate cable for Archimedes machines, although fitting the device still required approved service work to be performed. Monitors such as the Taxan 795 Multivision were only usable in multisync modes without the VIDC enhancer whose accompanying software sought to "redefine all modes" to be compatible with the display as well as providing new modes.
One drawback of VIDC enhancer solutions was the increased memory bandwidth used by the VIDC at its newly elevated frequency, slowing down machines when using higher resolution modes, particularly machines with ARM2 processors and slower memory busses. Consequently, other solutions were adopted to work around the limitations of the built-in display hardware, notably "graphics enhancers" such as the PCATS graphics enhancer from The Serial Port, and "colour cards" such as Computer Concepts' ColourCard and State Machine's G8 which provided a separate framebuffer, holding a copy of the normal screen memory, for use in generating a video signal independently of the system's main memory. This permitted higher refresh rates (up to 70 Hz) even for higher resolution modes, although the maximum size of the screen memory imposed by the VIDC () also imposed a limit on available resolutions and colour depths, with being the highest resolution 256 colour mode that could be supported. However, such cards were also able to support more flexible palettes in 256 colour modes than the VIDC, and for lower resolutions, greater colour depths offering over 32,000 colours could be supported. The ColourCard was reported to allow an ARM2 system to use a display mode with 16 colours (occupying 480 KB) with an operating speed of "160% of the speed of the considerably lower resolution Acorn mode 28", this being with 256 colours (occupying 300 KB).
Floating point arithmetic.
The Archimedes did not provide hardware support for floating point arithmetic as standard, but the system was designed so that one might be added, with a floating point co-processor instruction set architecture having been defined by Acorn for programs to use. Accompanying this, a software module providing an emulation of such a co-processor, handling these additional instructions in software written using conventional ARM instructions. The co-processor was described as a "cut-down" ARM with only eight registers available instead of sixteen, offering instructions to transfer values to and from memory (supporting single, double, extended double and packed binary-coded decimal representations), to transfer values between the main CPU and co-processor, to transfer status information from the co-processor, to perform unary and binary operations on values, and to perform comparisons.
In the first generation of Archimedes 300 and 400 series machines, only the 400 series had the appropriate expansion capability to add a floating point unit (FPU) or co-processor, although the emulator was supported on all models. The expansion capability was retained in the 400/1 series. The FPU expansion card was delivered for the R140 workstation and 400 series in 1989, priced at £599 plus VAT, and was based on the WE32206, with a "protocol converter chip" being used to translate between the ARM and the WE32206. The WE32206 card was also offered for Acorn's Springboard expansion card for IBM PC compatibles.
The Archimedes models based on the ARM3 processor supported a completely new "arithmetic co-processor" or "floating point accelerator" known as the FPA10. Released in 1993 for the R260 workstation and the A540 and A5000 machines, priced at £99 plus VAT, the FPA device was fitted in a dedicated socket on the processor card for the R260 and A540, or in a motherboard socket in the A5000. It offered a peak throughput of 5 MFLOPS at 26 MHz.
List of models.
Also produced, but never sold commercially were:
Impact.
A mid-1987 Personal Computer World preview of the Archimedes based on the "A500 Development System" expressed enthusiasm about the computer's performance, that it "felt like the fastest computer I have ever used, by a considerable margin", indicating that the system deserved success in the education market and might have more success than Acorn's earlier models in the business market, comparing favourably to the Mac II or IBM PS/2 80. Similar enthusiasm was reflected by the same writer in a Byte magazine preview of the A310 the following month. Later coverage, around the start of 1989, of the arrival of RISC OS for the Archimedes praised the desktop and supplied applications, noting that "RISC OS is everything the Archimedes' original Desktop should have been but wasn't", and looked forward to future applications from Acorn and third parties, only lamenting that it was "a shame that this impressive environment was not in place at the Archimedes' launch, but it's still not too late for it to turn some heads".
The Archimedes was one of the most powerful home computers available during the late 1980s and early 1990s. Its main CPU is more powerful than the Motorola 68000 found in both the cheaper Amiga 500 and Atari ST machines, and the more expensive Macintosh and Amiga 2000. An 68000 has an average performance of roughly for 16-bit workloads and for 32-bit workloads, with peak performance of for simpler 16-bit instructions. The yields for 32-bit workloads in repeatable benchmark tests.
By early 1991, 100,000 Archimedes machines had been sold, with the A3000 being the largest selling computer in UK schools, with Acorn's Archimedes and Master 128 accounting for 53 percent of sales in an eight month period during 1990, and with the 32-bit machines "outselling the Master 128 by a factor of two to one". By mid-1992, a reported 180,000 Archimedes machines had been sold, again due to strong A3000 sales. The range won significant market share in the education markets of the UK, Ireland, Australia and New Zealand; the success of the Archimedes in British schools was due partly to its predecessor the BBC Micro and later to the Computers for Schools scheme organised by the Tesco supermarket chain in association with Acorn, and most students and pupils in these countries in the early 1990s were exposed to an Archimedes or A-series computer. The Archimedes range was available in the US and Canada via Olivetti Canada.
By the mid to late 1990s the UK educational market began to turn away from the Archimedes. Macintosh computers and IBM PC compatibles eclipsed the Archimedes in their multimedia capabilities. The Tesco Computers for Schools scheme later changed partnership from Acorn to RM plc and many other computer-related suppliers, which also led to the decrease of the Archimedes' educational market share. Acorn itself gradually moved its focus away from computers and instead began exploiting the lucrative ARM processor technology as a separate enterprise through the spin off Arm Holdings which it had founded in 1990.
Legacy.
Between 1994 and 2008 a model superseding the Archimedes computer, the Risc PC, was used in television for broadcast automation, programmed by the UK company Omnibus Systems. Original desktop models and custom made 19-inch rack models were used to control/automate multiple television broadcast devices from other manufacturers in a way that was unusual at the time. It was used at several large European television stations including the BBC, NRK, TMF (NL, UK).
Also between 1994 and 2004 the Archimedes and Risc PC models were used for teleprompters at television studios. The hardware was easy to adapt for TV broadcast use and cheaper than other hardware available at the time.
Curiosity.
"Autom@tedVisualMusic" visualmusic software, creates images and sounds in relation to precise correspondences sound-symbol-color, producing multiple variations, written by Sergio Maltagliati, from experiences of the visual "HomeArt" programs designed by Pietro Grossi in the '80s, in the language BBC BASIC with computer Acorn Archimedes A310.