What is an Acorn Computer?



Acorn Computers existed for 20 years and produced many different models. Many of the models were produced in more than one configuration, the amount of memory, size of disc, OS version or bundled software varying between them. Once the computer was sold, the owner may have added ROMs, expansion boards, podules, bigger discs and other upgrades. During its life, the computer may have developed a fault and been repaired replacing some original parts with newer, different ones. Finally the collector (e.g. me) may have taken parts from several non-working computers to create a working computer that is representative of its model.

Both during and after Acorn Computers existance, third parties have been using Acorn's technology to make their own computers, whether it is a Viglen cased BBC Micro, a Torch Computer with a BBC I/O processor, a Pace STB or a Castle Iyonix . This does pose the question of where do you draw a boundary, is it only computers made by Acorn, with an Acorn logo, or do others count as well?

What is a BBC Micro?

Let's consider the BBC microcomputer  after all that should be fairly simple. But no, the model A , model B and model B+, give three different types of BBC Micro . But the Acorn product codes include:

Then add in the BBC micros made for German (GNB14) and US (UNB09) markets, and you get 10 Different BBC micros. However there are also the different motherboards, certainly Issue 2, 3, 4 and 7 exist for both the model A and model B which gives another 4 models for a total of 14 different models from Acorn.

But there are also the reboxed BBC Micros which typically give a seperate keyboard and system unit and include the disc drives in the system unit (e.g. Viglen) should they be included?

What is an Archimedes?

Acorn produced the Achimedes  range for about 4 years from 1987 to 1991. The basic Archimedes when through many incarnations from the original A3xx to the top of the range A540, along the way the A440 became the R140 and the A540 became the R260 running RISCiX. Many third parties produced upgrades for the Archimedes, Memory and disc upgrades were commmon as were ARM2 to ARM3 upgrades. At the same time the Operating System went from Arthur to RISC OS 2 to RISC OS3.

One of my Archimedes has an A420/1 badge on the front, a serial number on the case for an A440/1, and I changed the motherboard because the original one has vandalised!

Meanwhile Acorn had started to bundle software with the Archimedes. The first one was the Learning Curve bundle aimed at the education market. These bundles naturally had their own product codes even though the hardware was identical to other unbundled Archimedes.

The A3010, A3020 & A4000

The A3010, A3020 and A4000 which replaced the Archimedes range, had fewer hardware options (more memory, slightly bigger discs and an optional monitor). But to make up for this Acorn launched more bundled products as the Learning Curve was joined by Early Years and Home Office.
Unless I find a complete bundled package in this range, I think I will have to restrict myself to a representative selection of hardware.

The RiscPC

For a collector, the Risc PC  is the real nightmare. Originally introduced in 1994 as the Risc PC 600 , new models were launched in January 1995 with a CDROM drive and again in July1995 with a faster ARM610 CPU and updated RISC OS. Then there were the Learning Curve, Early Years and Home Office editions. I think there were 10 different versions, but there might have been more.

The Risc PC 700   was introduce in July 1995 and there were at least 5 different version including an X system terminal. But there were also Early Years, Learning Curve and Home Office editions.

The StrongARM Risc PC  was launched in September 1996 with a 202MHz StrongARM CPU and a new version of RISC OS. A year later an upgraded StrongARM Risc PC was launched with a 233MHz StrongARM CPU and another upgrade to RISC OS.

Each of the versions of the Risc PC had various hardware options, ever more memory, bigger discs, faster CDROMs and Monitors. In addition there were still the bundle software packages.

But far worse from a collectors point of view the Risc PC is just so easily upgraded. Most users will have upgraded an early Risc PC at least once, more memory, newer version of RISC OS, a StrongARM CPU etc. So what is described on the case as a Risc PC 600 and has a Risc PC 600 Product Code is nothing of the sort! My own Risc PC 600 is like this, I think that the only original part is the case!

Finally Castle has continued to manufacture the Risc PC and even development a new version in the Kinetic Risc PC. RISCOS Ltd have continued to develop RISC OS. So the Risc PC has had 4 generations of CPU (counting the Kinetic), 5 different OS versions, grown from 2 MB RAM to 256MB (or more?), discs have grown from 210MB to 20GB (or 40GB or 80GB or more?) . What a remarkable design!

So what is a Risc PC? You decide.

Acorn Badged OEM hardware

Don't forget that Acorn also rebadged OEM hardware. The best examples are the Pocketbook I and II  which were Psion 3 and 3a with minor changes and an Acorn badge. Possibly the worst was the rebadged Ollivetti PCs. Are these Acorn Computers?


After much debate, I have come to the conclusion that an Acorn computer is one that had an Acorn badge and was sold by Acorn, OR uses Acorn technology as the key components, especially RISC OS and ARM CPUs in recent years.

I shall attempt to build a representative collection of Acorn Computers which others can use as a reference point when confronted by a strange computer. Therefore I will rebuild computers to their original specifications, in some cases downgrading them. In almost all cases I will ensure I have working examples.

But in the end it is an Acorn compter, because I say it is for this collection. If you have a different definition, that's fine by me!