I ran my own blog from November 2006 till October 2014. All posts are still online, but I don't have time to update it anymore. Please note that all images and media files have been removed when the backup was moved to a new host in early 2016. Enjoy!

Acorn Archimedes - A Computer Way Ahead Of Its Time

12. march 2008

The Acorn Archimedes was the first RISC based home computer and was introduced long before Apple moved to the PowerPC RISC architecture.

First introduced in 1987, the Acorn Archimedes 300 and 400 computers offered outstanding features for that time: a 32-bit RISC processor, a modern operating system (Arthur OS, later renamed to RISC OS), built-in harddisk controllers, 8 channel stereo sound and 256 color graphics.

The second generation A3000 offered an 8 MHz ARM 2 and 1 MB of RAM, it used a combined computer-keyboard design similar to the Amiga 500 or Atari ST computers, while its powerful RISC CPU offered about 4 to 5 times the power of the Motorola 68000 CPU used by most of its rivals (including the Amiga, the Atari ST and the Apple Macintosh).

The Archimedes became very popular in the the education markets of the UK, Ireland and Australia, but it was never very successful outside of this niche - despite the fact that it was a technical revolution for that time.

In 1991, the A5000 was launched featuring the new 25 MHz ARM3 processor, up to 4 MB of RAM and 80 MB hard drives, VGA resolutions of up to 800×600 pixels and a disk drive that could read both Atari and DOS disks. It was followed by the next generation A30x0 and A4000 computers as well as by the A4 laptop computer using a 640 × 480 pixels greyscale LCD display.


But the UK educational market had already begun to drop the Archimedes architecture and started switching over to Apple Macintosh and Windows PC computers during the early 1990s. Archimedes sales dropped significantely and Acorn had to find a solution for this problem.


In 1994 Acorn launched the Risc PC, a modular design based upon Archimedes hardware and running RISC OS. Acorn also offered on optional CPU daughterboard featuring an Intel x86 CPU so that the Risc PC could run the popular Windows operating system.

During the following years Acorn struggled to survive while RiscPC sales were still low, and finally they had give up. The successor of the Risc PC, the so-called Phoebe 2100, should have arrived in late 1998, but it was never released despite thousands of pre-release orders.

There were only two Phoebe 2100 prototypes, they ran the all new RISC OS 4 and featured a 233 MHz StrongARM RISC CPU (ready for multiprocessor upgrades), a 64 MHz front side bus, up to 512 MB of RAM, high resolution graphics of up to 1280 x 1024 pixels with 32, 768 colours, a PCI bus and a large number of further innovations.