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RISC OS After Acorn

[Phoebe]     [Computers] 


The Background  section provides a brief history of the break up of Acorn Computers and what happened next. After that there are brief sections on each of the companies that built (or attempted to build) RISC OS based computers and RISC OS Ltd which provided continued the development of RISC OS. The companies are:


On "Black" Thursday 17th September, 1998 Acorn closed down their Workstation Division, cancelled the RiscPC 2  (aka Phoebe 2100) and cancelled the Acorn World show in 1998. The RISC OS market fragmented. In July 1999 Element 14 completed a buy out from Acorn and would concentrate on the set top box market. In October 2000 Element 14 was bought by Broadcom.

RISCOS Ltd was a new company jointly founded by many of the remaining companies and leading individuals in the RISC OS marketplace. Its mission was to continue RISC OS development where Acorn left off. After discussions with Acorn initially, and subsequently with Element 14, in January 1999 RISCOS Ltd obtained a license to sell Acorn's existing versions of RISC OS and to continue development of desktop RISC OS and sub-license desktop RISC OS to 3rd parties. Element 14 retained the ownership of RISC OS and would continue to develop it for Network Computers and similar devices.

When Element 14 was broken up, Pace Micro Technology Ltd bought RISC OS, but RISCOS Ltd's license was not affected. Pace continued to develop RISC OS for use in Set Top Boxes and other appliances. Later Pace sold RISC OS to Castle. This eventually precipitated the 2004 license dispute between Castle and RISCOS Ltd, which after a lot of confusing rattle throwing (for those on the outside), many misleading and contradictory statements (from those claiming to be on the inside) and silence from the 2 parties, was allegedly amicable settled. However RISC OS has forked, probably irreversably, into Castle's RISC OS 5 and RISCOS Ltd RISC OS 4, Select and RISC OS 6.

In Dec 2006 RISC OS Open Ltd  (ROOL) was launched to open source RISC OS 5. After a long pause while license terms were sorted out, ROOL started release RISC OS 5 sources. RISC OS Ltd are NOT part of ROOL and RISC OS 4, Select and RISC OS 6 sources are not available from ROOL. Recently there has been announcement that ROOL and RISC OS Ltd will cooperate to standardise and maintain common RISC OS interfaces.

Advantage Six

Advantage 6  owns Stuart Tyrrell Developments  which produces add-ons and upgrades for Acorn computers. Advantage Six has produced the A75 and A6, A6+ and A6T4 Windows computers which run Virtual Acorn .

In 2004 Advantage 6 announced the A9 range based on the ARM9 processor including the A9Home running RISC OS Adjust32 OS from RISCOS Ltd. In 2005 Advantage 6 demonstrated the A9Home at the 2005 Wakefield show and started selling beta test versions to experienced users. In 2006, also at the Wakefield show, CJE Micros started selling the A9home to the general public. [More details ] 


Castle had bought the rights to the RiscPC and A7000+ from Element 14 (the renamed Acorn) and continued to manufacture and sell them. Castle also developed the Kinetic RiscPC CPUcard which included on board RAM to bypass the RiscPC's slow memory bus.

Castle produced the Neuron 100 embedded computer, based on the ARM7500FE. A StrongArm version, the Neuron 200 was planned. The Neuron could run RISC OS or Linux/NetBSD. The Neuron supported very little by way of I/O and relied on the Cortex board to provide the required ports.

In 2002 Castle lauched the first native 32bit workstation, Iyonix, based on the Intel Xscale CPU. [more details] 


Cerilica Ltd

In 1998 Cerilica Ltd announced a high end graphics workstation, based on the Millipede Graphics  Imago motherboard, called the Nucleus , and showed a prototype at the Wakefield 2000 Show. In 2003 the one-off case was sold on eBay because the Imago motherboard was never completed and the Nucleus abandoned.



In 2002 Cumana launched the Slym Citrix client. It was based on the Castle  Neuron and Cortex boards.


Element 14

In July 1999 Element 14 was formed after a buy out of Acorn's Digital TV division. It developed the Active Set Top Boxes. It was bought by Broadcom in October 2000. [more details] 


IMS (Innovative Media Solutions)

In May 1998 IMS, in partnership with Interconnex UK Ltd announced a RISC OS portable named Peanut. It was based on the ARM7500FE and ran RISC OS3.71, under license from Acorn. See New RISC OS Portable from IMS  for the news from the 1998 Wakefield RISC OS show. It was cancelled before it was completed due to component supply problems. Interconnex took over IMS in Nov 1998.



MicroDigital was set up from Focus IT to design, develop, manufacture and market new RISC based computers. MicroDigital produced their own design RISC OS computers. First the Medi, followed by the Mico, the Alpha and finally by the Omega. [more details] 
MicroDigital ceased trading in 2005 and in 2006 their domain names expired and websites disappeared.


 Millipede Electronic Graphics

Millipede design and manufacture broadcast video boards e.g. Prisma3 and Alphalock Studio. Because of the limitations of the aging RiscPC, in 1999 Millipede designed a replacement motherboard called the Imago [Wanted]. Although demonstrated at user groups and RISC OS Shows, the Imago never went into production and public sale due to technical difficultiess with the FPGAs which replace the custom Acorn chips (VIDC and IOMD). [more details]



Not strictly "after Acorn" but near the end NetProducts produced the NetStations, based on Acorns NetStation, for NChannel. [more details ]



Pace used the NC OS derivative of RISC OS in Set Top Boxes, including the Bush Internet TV set top boxes. Later Pace first licensed and then sold RISC OS to Castle and now has no involvement with RISC OS. [more details] 



When Acorn closed its workstation division and cancelled the launch of Phoebe (Risc PC 2), a consortium of people involved with the Acorn hardware and software markets got together to negotiate a license to continue developement of RISC OS. The negotiations were eventually successful and in 1999 RISC OS Ltd was granted a license to complete development of RISC OS 4 and market it as an upgrade for Risc PCs and A7000/A7000+ and for new machines. RISCOS Ltd acquired the latest Acorn RISC OS source as part of its license agreement. This had been previewed by Acorn as RISC OS 3.80, and would have been lauched as RISC OS 4 for Phoebe. In July 1999 RISC OS 4 was released in ROM, and has been the OS for all new RISC OS designs. [more details ]



RiscStation produced the R7500 range. They also announced but failed to deliver a new RISC OS laptop to replace the A4. [more details] 


Simtec Electronics

Simtec produced a number of evaluation/development boards using ARM CPUs as well as a number of other products for Acorn computers. The Simtec ARM7500ATX board was used in the RiscStation R7500. RISCOS Ltd used the same ARM7500ATX board for the test platform for Embedded RISC OS 4.06. [more detals ]



Xemplar was founded in April 1996 as a joint 50/50 venture between Acorn and Apple to sell into the Education market. Ok, so it is not strictly after Acorn, but I have included it here. In January 1999 Acorn sold its 50% to Apple for £3 million. Xemplar resold the Acorn NetStation to the education market as the Xemplar Matrix NC. [more details]