The Acorn Archimedes was Acorn, Ltd's first general purpose home computer based on their own ARM RISC CPU, and spawned a family of very capable machines with various options.

Table of contents
1 Description; Early models
2 The A3000 and A5000
3 A new range and a laptop
4 Significance and impact
5 External links

Description; Early models

The first models were released in June 1987, as the 300 and 400 series. The machines differed primarily in that the 400 series included more slots (four instead of two) and a ST506 controller for an internal hard drive. Both models included the Arthur OS (later versions to be called RISC OS, see below), BBC BASIC and an emulator for Acorn's earlier BBC Micro, and were mounted in excellent two-part cases with a small central unit, monitor on top, and a separate keyboard and three-button mouse.

Four models were initially released with different amounts of memory, the A305, A310, A410 and A440. The 300 and 400 were followed by a number of machines with minor changes and upgrades:

  • (A500 - 4 MB RAM, Archimedes development machine, never sold [1])
  • A305 - 512 KB RAM
  • A310 - 1 MB RAM
  • A410 - 1 MB RAM
  • A420 - 2 MB RAM, 20 MB hard disk
  • A440 - 4 MB RAM, 40 MB hard disk
  • (A4xx/1 editions with improved memory controller)
  • A540 - 4 MB RAM, 100 MB hard Disk
  • (A680 and M4 - 8 MB RAM, RISCiX development machines, never sold)
  • R140 - 4 MB RAM,   52 MB hard disk, RISCiX UNIX workstation
  • R260 - 8 MB RAM, 100 MB hard disk, RISCiX UNIX workstation
  • R225 - 4 MB RAM, RISCiX UNIX network computer

The A3000 and A5000

Work began on an upgrade to the Arthur OS as Arthur 2, but with the release of the Hollywood movie of the same name the OS was renamed to RISC OS 2. This seemed like a good time to introduce a number of new machines as well, and the 300 series was replaced with the new A3000 series in May, 1989.

Unlike the 300, the 3000's were mounted in single-part cases with the keyboard attached to the main unit. This makes them harder to place on a desk because the monitor cannot be put on top. It also eliminated one of the slots, there simply wasn't room for it. Oddly the 400 series continued on after switching a few options. It seems unlikely that the less expensive 3000 style case would be able to save any real amount of money given that the 400 continued to be produced.

The A5000 had a two part case, but a different design to the earlier models. It used the new ARM3 processor while the A3000 had the older ARM2. Both the A3000 and the A5000 ran RISC OS 3. In summary:

  • A3000 - 1 MB RAM
  • A5000 - 1 MB RAM, 40/80 MB hard disk (and the A5000 Alpha Variant - 2/4 MB RAM, 80/120 MB hard disk)

A new range and a laptop

In 1991, a new range was produced, using the ARM250 processor (an ARM2 with integrated memory/video controller; not as fast as the ARM3, though) and RISC OS 3.1. The A30x0 had a one-piece design, similar to the A3000, while the A4000 looked like a slightly slimmer A5000.

There was also a laptop, the A4, and later an updated A5000 (using a 33MHz ARM3 instead of 25MHz).
In summary, minus the A5000:

  • A3010 - 1 MB RAM (and the A3010 Special Edition)
  • A3020 - 1 MB RAM, 60MB hard disk
  • A4000 - 2 MB RAM, 80MB hard disk
  • A4       - 2 MB RAM (A5000 hardware in a laptop case)

The A7000, despite its name's being reminiscent of the Archimedes naming-conventions, was actually a low-end
RiscPC – the line of RISC OS computers that succeded the Archimedes in 1994.

Significance and impact

The Archimedes was in fact the most powerful home computer during the late 1980s; it could run a piece of software faster and with better visual quality than the more-famous and better selling Atari ST and Commodore Amiga. This was mainly because the ARM CPUs were not untypically three times faster than the competition (the Motorola 68000 family), and thus was able to control and respond to the graphics hardware in a much faster manner.

Despite a technical edge having been fully realised upon the release of RISC OS 2 in 1989, the Archimedes only ever met a moderate success, becoming very much a 'minority' platform outside of niche markets (not unlike the Apple Macintosh). The education markets of the UK, Ireland and Australasia were among the platform's most dominant zones of importance, along with specialised professional work such as radio, medical and train station management. Most students/pupils in the aforementioned countries in the early 90s will have seen/used an Archimedes.

The platform was very unusual in that it was and still is largely unknown outside of a handful of countries where most of its sales occurred. Very few people in Asia or the USA have ever heard of the Archimedes.

External links