<operating system, abuse> The sort the speaker is used to. People from the BSDophilic academic community are likely to issue comments like "System V? Why don't you use a *real* operating system?", people from the commercial/industrial Unix sector are known to complain "BSD? Why don't you use a *real* operating system?", and people from IBM object "Unix? Why don't you use a *real* operating system?" See holy wars, religious issues, proprietary, {Get a real computer!}. [Jargon File] (1997-03-12)

A real-time operating system (RTOS) is an operating system (OS) for real-time applications that processes data and events that have critically defined time constraints. A RTOS is distinct from a time-sharing operating system, such as Unix, which manages the sharing of system resources with a scheduler, data buffers, or fixed task prioritization in a multitasking or multiprogramming environment.

<operating system> (RTOS) Any operating system where interrupts are guaranteed to be handled within a certain specified maximum time, thereby making it suitable for control of hardware in embedded systems and other time-critical applications. RTOS is not a specific product but a class of operating systems. [Other criteria?] (1998-02-27)

Real Time Operating System (Reference: OS, Interdata, Prime, ...)

<operating system> A Data General operating system developed in the 1970s or 1980s. When used in conjuction with a BASIC (e.g. Business Basic) it could support 16 concurrent users at the record locking level and two printers all on 128K memory. Reputedly IBM wanted to license this for the first IBM PC but DG turned them down so they went to Microsoft instead. How different the world could have been. [Before or after IBM wanted CP/M?] (1997-11-23)

Real-Time Operating System

(operating systems)

An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.

<operating system> (OS) The low-level software which handles the interface to peripheral hardware, schedules tasks, allocates storage, and presents a default interface to the user when no application program is running. The OS may be split into a kernel which is always present and various system programs which use facilities provided by the kernel to perform higher-level house-keeping tasks, often acting as servers in a client-server relationship. Some would include a graphical user interface and {window system} as part of the OS, others would not. The {operating system loader}, BIOS, or other firmware required at {boot time} or when installing the operating system would generally not be considered part of the operating system, though this distinction is unclear in the case of a {rommable operating system} such as RISC OS. The facilities an operating system provides and its general design philosophy exert an extremely strong influence on programming style and on the technical cultures that grow up around the machines on which it runs. Example operating systems include 386BSD, AIX, AOS, Amoeba, Angel, Artemis microkernel, BeOS, Brazil, COS, CP/M, CTSS, Chorus, DACNOS, DOSEXEC 2, GCOS, GEORGE 3, GEOS, ITS, KAOS, Linux, LynxOS, MPV, MS-DOS, MVS, Mach, Macintosh operating system, Microsoft Windows, MINIX, Multics, Multipop-68, Novell NetWare, OS-9, OS/2, Pick, Plan 9, QNX, RISC OS, STING, System V, System/360, TOPS-10, TOPS-20, TRUSIX, TWENEX, TYMCOM-X, Thoth, Unix, VM/CMS, VMS, VRTX, VSTa, VxWorks, WAITS. {FAQ (ftp://src.doc.ic.ac.uk/usenet/news-info/comp.os.research)}. Usenet newsgroup: news:comp.os.research. [Jargon File] (1999-06-09)