RISC World

Castle buys RISC OS technology from Pace

Issued by Castle Technology Ltd

4th July 2003 - Castle Technology Ltd today announced the purchase of the RISC OS technology from Pace Micro Technology plc. The transaction involves the payment of an undisclosed cash sum, ongoing technical support for Pace`s existing products and the grant of a licence back to Pace for intellectual property rights. Castle, based in the UK, have been developing and supplying RISC OS products for over 10 years and this acquisition will ensure that RISC OS products continue into the future. Castle have also formed a joint venture with Cambridge based Tematic Ltd who will develop, market and support an embedded version of RISC OS which has been designed for use in the new generation of smart multimedia products for the high volume consumer electronics market, while Castle will continue to service the desktop market. Anthony Dixon, Company Secretary of Pace commented, "We are delighted to have concluded this transaction with Castle. This allows Pace to maintain the necessary intellectual property rights and technical support for our RISC OS based IP gateways through these new licence agreements. We wish Castle every success for the future". Jack Lillingston, Castle`s Managing Director, said, "The purchase of this technology combines perfectly with our expertise in manufacturing and marketing RISC OS computers (illustrated by our recent success with the launch of the IYONIX pc). This deal will allow us to be at the heart of exciting new products." Jack concluded, "RISC OS provides a proven, small-footprint solution, for cutting edge products such as handheld media devices; we are all very excited with this new development and relish the future for RISC OS" .


RISC OS development was started in 1988 by Acorn Computers Ltd, Cambridge and acquired by Pace in 1999. RISC OS is a unique combination of hardware and software technology developed for desktop computers . It is also deployed in a number of commercially successful, consumer electronics products including Pace`s DSL4000 gateway, Internet TV devices and a variety of specialized embedded systems. Over 1 million units have been shipped with this technology. RISC OS technology is ideal for the new generation of ARM-based smart embedded devices because it is the most sophisticated and highest performance software environment currently available. It has been designed specifically for high volume, low-cost products that need to support a market-winning set of features with the absolute minimum memory and processor requirements.

About Castle Technology Ltd

Castle is the leader in the field of RISC OS desktop products, with a 10-year track record of year on year growth and a proven expertise in this area. In 1999 Castle took over the production of the Acorn range of desktop computers. Their latest development is the IYONIX pc - the first desktop computer in the world to use Intel`s XScaleŠ processor. Castle is based near Ipswich in Suffolk. For further information please visit Castle`s web site at

About Tematic Ltd

Tematic Ltd offers comprehensive production-ready design solutions for consumer electronic companies. The Tematic team has a proven track record for creating and delivering innovative products for their clients. Tematic can provide a complete, fastest time-to-market solution for companies who need to turn their ideas into revenue generating products in the shortest possible time. Tematic`s web site is at

About Pace Micro Technology plc

Pace Micro Technology plc (LSE: PIC) is a leader in digital television technology. The Company`s primary focus is the development of innovative home gateway (set-top box) solutions for operators, broadcasters, telecommunications companies and retail markets worldwide. In addition, Pace develops edge of network devices for service providers, in particular digital IP gateways for low-cost integrated voice and data services. Pace`s head office is in Shipley West Yorkshire, with further offices in Bracknell, Cambridge, the USA, France and Hong Kong. For further information, please visit Pace`s web site at


(In addition Castle Technology released this FAQ on the 16th of July - ED)

Q.Will RISC OS 4, Select and RISC OS 5 merge?
A.RISC OS 5 already contains most of the enhancements from RISC OS 4, however not all of the Select features apply to non-desktop applications. Additionally care must be taken to avoid RISC OS losing its competitive edge in other fields, with increased code size and loss of performance. Castle wish to maintain only one source tree, so RISCOS Ltd will continue to produce Select (containing Desktop specific features) and Castle will encourage RISCOS Ltd to migrate this to RISC OS 5.

Q.What does this mean for other hardware developers such as MicroDigital Limited and RiscStation Limited?
A.There are no changes to the current position; they can continue to ship their RISC OS 4 desktop computers; the only difference is that Castle now holds the head license instead of Pace.

Q.I want a license to use RISC OS - must I apply to Castle to get one?
A.Not necessarily. A number of companies have the ability to grant 3rd party binary licenses for RISC OS, for example RISCOS Ltd can licence RISC OS 4 for desktop computers. In addition they could also apply to Castle for an extension to include new hardware - there are no plans at all to withhold permission to any genuine volume applicant.

Q.Castle make hardware, isn't it a conflict of interests to also own the operating system?
A.No. Historically Acorn made hardware and owned the operating system, but didn't license RISC OS to competitors. The exciting difference here is that there is now the ability for 3rd parties to produce/market ARM based products featuring RISC OS, there would be no conflict as Castle will benefit from royalties for these products. As covered in the press release on July 4th Castle will forge new partnerships with mass-market consumer companies, this should become a major use for RISC OS in the future.

Q.What about !Browse, can I expect any updates?
A.Sadly after years of frozen development !Browse is now a long way behind in its standards compatibility. Though upgrading it to handle HTML4 and newer Javascript is theoretically possible, this is a huge task. As Oregano 2 already offers these features, and with the recent announcement of it's use in the Playstation 2, a huge amount of investment is being made in Oregano which should be very easy to port back to RISC OS in future versions of Oregano.

Q.Will a version of RISC OS 5 for the Risc PC and A7000 be released?
A.Although a simple HAL for IOMD based machines does exist for testing purposes it would require an unfeasible amount of work to turn it into a production quality version.

Additionally running in 32 bit mode on an old processor which still supports 26 bit mode doesn't really bring any benefits. 32 bit applications will of course still work on these machines (fitted with a 26-bit version of RISC OS) and can also use the new 32 bit APIs through the free CallASWI module, SharedCLibrary, and HAL module in a fully backwards-compatible manner.

The HAL module referred to above is available from

Q.When can I buy a legal version of RISC OS for emulation on my PC?
A.Emulator authors wishing to ship RISC OS for non-ARM platforms will be contacted shortly. It is expected that there will be a number of solutions available over the next few months.

Q.This is all very confusing! Who does what?
A.Put simply:

  • RISCOS Ltd will continue to produce versions (including Select) of RISC OS 4.
  • Castle also will encourage the production of a version of Select for RISC OS 5.
  • Pace continue to develop, produce and sell the DSL4000 IP gateway from their Cambridge based office.
  • Castle continues to ship its lightning fast IYONIX pc range, as well as granting new licenses (which don't overlap any existing exclusivity).
  • Tematic Ltd would be the first point of call for all new embedded versions of RISC OS.

Q.What new hardware is on the cards?
A.With the hardware abstraction layer (HAL) and fully 32-bit operating system, RISC OS can run on all ARM devices including ARM9, ARM10, ARM11 and XScale devices as and when they become available. Specific new hardware will depend on what individual companies negotiate with Castle.

Q.Is anyone working on an ARM laptop now?
A.As with previous attempts the major stumbling block is sourcing a case which has a long enough life span to be able to ensure supply. This doesn't rule out the possibility of selecting one of the many ready-made A4 sized industrial tablets based on fast ARM9 and XScale technology.

Issued by Castle Technology Ltd