(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.
computer The final addition to Acorn’s Archimedes family of personal computers, released in April 1994. The RiscPC allowed a second processor, e.g. an Intel 486 or a second ARM, to share the bus, memory and peripherals with the main processor. It also had full 24-bit colour graphics support. The Risc PC 600 (the first to […]
verb (used without object), rose, risen [riz-uh n] /ˈrɪz ən/ (Show IPA), rising. 1. to get up from a lying, sitting, or kneeling posture; assume an upright position: She rose and walked over to greet me. With great effort he rose to his knees. 2. to get up from bed, especially to begin the day […]
- Rise and shine
An expression used when waking someone up, as in It’s past seven, children—rise and shine! Originating as a military order in the late 1800s, shine here means “act lively, do well.”
- Rise from the ashes
Emerge as new from something that has been destroyed, as in A few months after the earthquake large sections of the city had risen from the ashes. This expression alludes to the legendary phoenix, a bird that supposedly rose from the ashes of its funeral pyre with renewed youth.