This website is an archived copy of "Chris's Acorns", now hosted by The Centre for Computing History as part of The Chris Whytehead collection.
To view the page in it's original forms without this header, append "?cfch-archive=orig" to the URL.

Castle Technology

[After Acorn]     [Companies ]


After Acorn pulled out of the desktop computer market in 1998, Castle acquired the rights to the A7000, RiscPC and NC and continued manufacturing them under the Acorn badge. Castle further developed the StrongARM RiscPC with the Kinetic RiscPC.

In 2002 Castle launched the Iyonix, the first 32-bit RISC OS computer.

On 25 September 2008 Iyonix Ltd (a.k.a. Castle) announced that from 30th September 2008 it would no longer be possible to buy a new Iyonix computer. The press release said:

25th September 2008


IOYONIX Ltd would like to announce that from the 30th September 2008 it will not be possible to order an IYONIX computer. There are however very limited supplies of IYONIX computers available for supply and where possible we will be delighted to supply computers before this date (orders will be dealt with on a first come first served basis and are limited).

From 1st October 2008 support for the IYONIX computer will continue through:

  1. the IYONIX dealer network
  2. the IYONIX website (
  3. by email (sales @ & support @

In the meantime Jack Lillingston & John Ballance would like to thank all their customers for their business and support over the last 15 years. IYONIX Ltd will continue to trade until stocks of IYONIX and other Acorn RISC OS parts and accessories are exhausted.

The opening up of the RISC OS source code through ROOL is unaffected by this announcement.

Jack Lillingston

Fax: 0870 705 8879
email: sales @
           support @

John Balance also posted to the Iyonix support list:

Iyonix 2: This would have been rather a nice machine.. dual core cpu etc .. absorbed many months of my design time. Then came the crunch question.. could we make it at a price people would pay, and would enough ACTUALLY pay that price.. rumours have suggested a build cost to a first batch of 10 to 30 machines of between 50 and 100k .. probably not unreasonable at commercial rates, considering the CPU had just under 1500 connections on it and itself would have cost over £100!.. that would mean that sales of several hundred units would be needed at similar costs to the current (almost) standard iyonix.

Would several hundred of you or others actually commit to this.. or would we be left thoroughly out of pocket?

To put it bluntly, we could not make the sums add up! - however hard we tried.

For the future, once the remaining stock of machines is exhausted (<10 first come first served) iyonix will continue to trade, as reported, in spares and accessories.

I shall be around, initially within iyonix, then in my own right, providing support as reasonably required.

Castle continues to license RISCOS as before.. all product work has been undertaken in iyonix in recent times to protect the IP ownership as others have rightly deduced.

So Thank You all for your support over the years.. It has been an interesting time.

So Goodbye Iyonix (and thanks for the chips?)

Manuals and documents



A7000+ Odyssey

Castle continued to manufacture the A7000+ and produced a upgraded version, the Odyssey. The main way to identify Castle made A7000+ is the CTLnnnnnnn serial numbers.

Here are further details and some pictures of the A7000+ Odyssey.


Castle continued to manufacture the RiscPC. The main way to identify Castle made RiscPCs is the CTLnnnnnnn serial number. In November 2003 Castle announced that manufacture of the RiscPC would cease because they were unable to source some components. [Wanted]

Kinetic RiscPC

Castle announced the Kinetic RiscPC in May 2000. The Kenetic RiscPC is a RiscPC with a Kinetic CPU card. The Kinetic CPU card is a 233MHz StrongARM CPU card with either 64MB or 128MB onboard SDRAM which speeds up memory access and gives an estimated 2.5 time performance boost. Existing RiscPCs can be be upgraded by swapping the existing CPU card for a Kinetic CPU card. [Wanted]


In October 2002 Castle launched a new 32 bit design, the Iyonix, using the Intel X-Scale 80321 CPU with PCI graphics and UDMA. With the new computer came a new 32bit version of RISC OS (RISC OS 5). It was the first new RISC OS computer since the RiscPC was launched in 1996.

Here are further details and some pictures of the Iyonix.