The ACORN ARCHIMEDES is a family of personal computers designed by
Acorn Computers Ltd in
ARM's RISC design – 32-bit CPU (26-bit addressing), running at 8 MHz , was stated as running at 4.5+ MIPS , which provided a significant upgrade from 8-bit home computers, such as Acorn's previous ones. Claims of being the fastest micro in the world and running at 18 MIPS were also made during tests.
The models in the family either omitted the Acorn or Archimedes part
of the name, with the first models named "
* 1 Description and history
* 1.1 Early models * 1.2 A3000 and A5000 * 1.3 New range and a laptop
* 2 List of models * 3 Significance and impact * 4 See also * 5 References * 6 External links
DESCRIPTION AND HISTORY
BBC Computer Literacy Project
Four models were initially released with different amounts of memory, the A305, A310, A410 and A440. The 540 was unveiled in September 1990, and included higher speed SCSI and provision for connecting Genlock devices. The 300 and 400 were followed by a number of machines with minor changes and upgrades:
A3000 AND A5000
Work began on a successor to the Arthur operating system . Initially named Arthur 2, it was renamed to RISC OS 2. New computers were shipped with it pre-installed. 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 Acorn A3000 (the 400 series was kept in production). Earlier models which shipped with Arthur could be upgraded to RISC OS 2 by replacing the ROM chips containing the operating system.
The A3000 used an 8 MHz ARM 2 and was supplied with 1 MB of RAM.
Unlike the previous models, the A3000 came in a single-part case
similar to the
A300 series, A400 series, R140 and A3000 machines had the VIDC1a video chip, which provided a wide variety of screen resolutions, such as those provided officially by the operating system:
* 160 × 256 with 4, 16 or 256 possible colours * 320 × 256 with 2, 4, 16 or 256 possible colours * 640 × 256 with 2, 4, 16 or 256 possible colours * 640 × 512 with 2, 4, 16 or 256 possible colours * 800 × 600 with 2, 4 or 16 possible colours
while the chip could be made to run others, such as:
* 1152 × 896 with 2 possible colours
where the palette range was 4096 colours (12-bit) and the VIDC1a had 16 hardware palette registers. This meant that in screen modes with sixteen colours or fewer, the colours could be mapped to any of the 4096 available. However, in 256 colour modes, 4 bits of the colour data were hardware derived and could not be adjusted. The net result was 256 colours, but only 16 of them could be assigned as desired, covering a range of the 4096 available colours. It also had no Horizontal sync interrupt, meaning that it was difficult to display additional colours by changing the palette for each scan line, but not impossible, thanks to the 2 MHz IOC timer 1. Many demos managed to display 4096 colour on screen or more with dithering It had also one hardware sprite, with 32 pixels width and unlimited height (by default used for the mouse pointer), where each pixel is coded on two bits: value 0 is for transparency, and the three others are freely chosen from the 4096 colour palette. A5000 with top removed
In 1991, the A5000 was launched. It 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 ). Its enhanced video capabilities allowed the A5000
to comfortably display
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 a third party upgrade.
NEW RANGE AND A LAPTOP
In 1992, a new range was produced, utilising the first ARM macrocell: the ARM250 microprocessor , a single-chip design including the functionality of an ARM3 chip without cache, the IOC1 (Input Output Controller), VIDC1a (VIDeo and sound Controller) and MEMC1 (MEMory Controller) 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 far smaller, 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.
Also 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
The A7000 , despite its name being reminiscent of the Archimedes naming conventions, was actually more similar to the RiscPC , 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 RiscPC (though by removing the CDROM, a backplane with one slot could be fitted).
LIST OF MODELS
Acorn R140 4 MB 47 MB ST506 ARM2 June 1989 £3,500 RISC iX workstation
Acorn R225 4 MB - ARM3 July 1990 £3,000 RISC iX network workstation
Acorn R260 8 MB 100 MB SCSI ARM3 July 1990 £5,000 RISC iX workstation
Acorn A5000 1, 2, 4 or 8 MB 20 MB to 160 MB IDE ARM3 September 1991 £999 or £1,499 25 or 33 MHz ARM3 processor, launched with various sub-models
2 or 4 MB
40 or 60 MB IDE (2.5")
£1,399 or £1,699
Notebook model with ARM3 processor clocked at 24 MHz, 640x480
Acorn A3010 1 MB - ARM2/ARM250 September 1992 £499 ARM250 processor (early models had an ARM2 mezzanine processor codenamed "Adelaide" )
Acorn A3020 2 MB 0–80 MB IDE (2.5") ARM250 September 1992 £799
Acorn A4000 2 MB 0–210 MB IDE ARM250 September 1992 £999
Also produced, but never sold commercially were:
SIGNIFICANCE AND IMPACT
The Archimedes was one of the most powerful home computers available
during the late 1980s and early 1990s; its main CPU was faster than
Motorola 68000 microprocessors found in the more popular Commodore
The computer was exhibited at the 1987 Personal Computer World Show ,
along with Amigas ,
The Archimedes won significant market share in the education markets
of the UK , Ireland ,
By the early 1990s, the UK educational market began to turn away from the Archimedes. Apple Macintosh computers or IBM compatible PCs eclipsed the Archimedes in their multimedia capabilities, which led to an erosion of the Archimedes market share. 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.
* ^ Anand Lal Shimpi (March 31, 2014). "ARM Partners Ship 50
Billion Chips Since 1991 - Where Did They Go?". ARM pointed out that
Cortex-A shipments overtook x86 in 2012
* ^ A B "Chris\'s Acorns -
RISC OS Performance Page".
Acorn.chriswhy.co.uk. 2008-10-31. Archived from the original on 18
July 2011. Retrieved 2011-06-13.
* ^ Hammond, Ray (1987-06-18). "'Fastest' micro in the world". New
Scientist. p. 41.
* ^ Pountain, Dick (October 1987). "The Archimedes A310". BYTE. p.
125. Retrieved 4 August 2014.
* ^ "Chris\'s Acorns: 32bit Upgrades & Expansions by company". Acorn.chriswhy.co.uk. 2008-10-31. Archived from the original on 18 July 2011. Retrieved 2011-06-13. * ^ "Chris\'s Acorns: 32bit Upgrades & Expansions by company". Acorn.chriswhy.co.uk. 2008-10-31. Archived from the original on 18 July 2011. Retrieved 2011-06-13. * ^ Announcing Acorn\'s A4 Portable - "... a quart in a pint pot" * ^ A B C D "300 SERIES A British Broadcasting Corporation Microcomputer" (PDF). Archimedes High Performance Computer Systems Retail Price List. July 1987. * ^ Cain, Chris (July 1989). "Acorn A3000". Personal Computer World. * ^ "A3010 Specs". Classicacorn.freeuk.com. Retrieved 2011-06-13. * ^ "Rare A500 surfaces on ebay Drobe.co.uk archives". Drobe.co.uk. Archived from the original on 8 June 2011. Retrieved 2011-06-13. * ^ "News from the PCW Show". Crash . Newsfield Publications . November 1987. Archived from the original on 6 June 2011. Retrieved 2011-07-12. Despite the number of STs and Amigas demonstrating titles at the show, despite whiz-bang demos of Acorn’s Archimedes, and despite the undeniable interest shown in the games machines, The PCW Show indicated to me that it’s a bit early to announce the death of the 8-bit machines. * ^ Roger Wilson (April 10, 1990). "Acorn Micros?". Newsgroup : comp.misc . Usenet: 5357@ucrmath.UCR.EDU . Retrieved June 14, 2011.
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