RISC OS definition of RISC OS in the Free Online Encyclopedia.

(operating system)

RISC OS - (Reduced Instruction Set Computer Operating System) The operating system originally developed by Acorn Computers for their Archimedes family of personal computers.

RISC OS replaced the Arthur operating system used on the first Archimedeses.

It is written in ARM assembly code and distributed on ROM so it takes up no disk space and takes no time to load. It supports cooperative multitasking with memory management and includes a graphical user interface or "WIMP". It is written in a highly modular style and makes extensive use of vectors so it is easy to modify and extend by loading new modules in RAM. Many system calls (called "SWIs" - software interrupts) are available to application programmers and some of these are available as user comands via a built-in command-line interpreter. RISC OS also supported outline fonts when only bitmap fonts were available on most other platforms.

Following the virtual demise of Acorn, development of RISC OS 4 was taken over by RISCOS Ltd on 1999-03-05 and released on 1999-07-01.

Latest version: 4.39, as of 2004-09-21.

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No references found	RISC OS was developed in the 1980s, before Microsoft had achieved quite the level of global dominance that it now enjoys. E-clips: Maths whizz opens up web by Daily Post (Liverpool, England) Acorn Group Plc is considering a plan to spin off its RISC OS as a separate company following the spin-off of its ARM Holdings Plc, which subsequently became a much larger and more successful company than its parent. ACORN PLANS TO SPIN-OFF NEW SOFTWARE SUBSIDIARY by Computergram International The company has previously announced relationships with OEMs who plan to port ICA to EPOC32, RISC OS and QNX OS embedded operating systems. Citrix Announces ICA Embedded Client for Microsoft's Windows CE ... by Business Wire	ripple index ripple lamina ripple load cast ripple mark Ripple Marks ripple quantity ripple scour ripple symmetry index ripple tank ripple till ripple voltage ripple-carry adder Rippy, James Fred riprap rips ripsaw ripsawing Ripsime Ripsime Misakovna Pogosian Ripsime Pogosian ripstop fabric RIR RIS Risabha's Nirvana and Mauni Amavasya RISC RISC OS RISC processor RISC System/6000 RISC-based system RISCiX RiscPC Rise rise and run rise of bottom rise of floor rise of tide rise pit rise time rise-and-fall table risen molding riser riser board riser card riser diagram riser height riser pipe riser plate riser-angle indicator Rishat Abdullin Rishat Mukimovich Abdullin Rishi Panchami	Risa En Voz Alta Risa Hacia fuera Ruidosamente RISAA Risabha's Nirvana and Mauni Amavasya RISAC Risachief RISAFF RISAG RISAL Risala Risalah Risalah Data Keselamatan Kimia RISAOM RISAP Risaralda RISAS RISAT RISAT-2 RISB RISBAP RISBDC RISC RISC RISC RISC RISC RISC Advanced Architecture Server RISC Central Processing Unit RISC OS Risc OS on x RISC OS Unicode Font Library RISC OS User Group of London Risc PC RISC processor RISC processor RISC Single Chip RISC System/6000 RISC System/6000 RISC System/6000 SP RISC System/6000 SP RISC Technology RISC-based RISC-based Personal Computer RISC-based system RISC-based system RISC-OS Risca Risca Risca Community Comprehensive School Riscatto di debiti RiSCC RISCC rating Rischio di credito RISCI RISCiX RISCL Risco cambial Risco de deterioracao de conjuntura

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RISC OS was developed in the 1980s, before Microsoft had achieved quite the level of global dominance that it now enjoys.

E-clips: Maths whizz opens up web by Daily Post (Liverpool, England)

Acorn Group Plc is considering a plan to spin off its RISC OS as a separate company following the spin-off of its ARM Holdings Plc, which subsequently became a much larger and more successful company than its parent.

ACORN PLANS TO SPIN-OFF NEW SOFTWARE SUBSIDIARY by Computergram International

The company has previously announced relationships with OEMs who plan to port ICA to EPOC32, RISC OS and QNX OS embedded operating systems.

Citrix Announces ICA Embedded Client for Microsoft's Windows CE ... by Business Wire