For the Macintosh operating system, see Mac OS 9. Mac OS 9 is the final major release of Apple's "Classic" Mac OS.

OS-9
Website	Microware OS-9
Company/ developer	Microware (now owned by RadiSys Corporation)
Programmed in	Machine code
OS family	Unix-like real-time operating systems
Source model	?
Latest stable release	? / ?
Available language(s)	?
Supported platforms	Motorola 6809, Motorola 68000-series
Kernel type	Real-time kernel
Default user interface	Command line interface
License	?
Working state	Current

OS-9 is a family of real-time, process-based, multitasking, multi-user, Unix-like operating systems, developed in the 1980s, originally by Microware Systems Corporation for the Motorola 6809 microprocessor. A website (alternatively web site or Web site, a back-construction from the Proper noun World Wide Web) is a collection of Web pages The software industry comprises businesses involved in the development, maintenance and publication of Computer software. A software developer is a person or organization concerned with facets of the software development process wider than design and coding a somewhat broader scope of Microware is a US corporation that produced the OS-9 real-time Operating system. RadiSys Corporation is a supplier of Embedded systems and related technology with corporate headquarters in Hillsboro Oregon within the Portland metropolitan Machine code or machine language is a system of instructions and data executed directly by a Computer 's Central processing unit. A Unix-like (sometimes shortened to *nix) Operating system is one that behaves in a manner similar to a Unix system while not necessarily conforming A real-time operating system ( RTOS; generally pronounced as "are-toss" is a multitasking Operating system intended for real-time In the Philosophy of language, a natural language (or ordinary language) is a Language that is spoken or written in phonemic-alphabetic or phonemically-related The Motorola 6809 is an 8-bit (arguably an 8/ 16-bit) Microprocessor CPU from Motorola, introduced circa 1979 The Motorola 68000 is a 16/32-bit CISC Microprocessor core designed and marketed by Freescale Semiconductor (formerly Motorola Semiconductor In Computer science, the kernel is the central component of most computer Operating systems (OS In Computer science, real-time computing (RTC is the study of hardware and software systems that are subject to a "real-time constraint"—i The user interface (or Human Computer Interface) is the aggregate of means by which people&mdash the users '&mdash interact with the System A software license (or software licence in commonwealth usage is a Legal instrument governing the usage or redistribution of copyright protected software In Computer science, real-time computing (RTC is the study of hardware and software systems that are subject to a "real-time constraint"—i In computing a process is an instance of a Computer program that is being sequentially executed by a computer system that has the ability to run several computer In computing Multitasking is a method by which multiple tasks also known as processes, share common processing resources such as a CPU. Multi-user is a term that defines an Operating system or Application software that allows concurrent access by multiple users of a Computer. A Unix-like (sometimes shortened to *nix) Operating system is one that behaves in a manner similar to a Unix system while not necessarily conforming An operating system (commonly abbreviated OS and O/S) is the software component of a Computer system that is responsible for the management and coordination The 1980s was the decade spanning from January 1 1980 to December 31 1989. Microware is a US corporation that produced the OS-9 real-time Operating system. The Motorola 6809 is an 8-bit (arguably an 8/ 16-bit) Microprocessor CPU from Motorola, introduced circa 1979 A microprocessor incorporates most or all of the functions of a Central processing unit (CPU on a single Integrated It is currently owned by RadiSys Corporation. RadiSys Corporation is a supplier of Embedded systems and related technology with corporate headquarters in Hillsboro Oregon within the Portland metropolitan

The OS-9 family was popular for general-purpose computing and remains in use in commercial embedded systems and amongst hobbyists. An embedded system is a special-purpose Computer system designed to perform one or a few dedicated functions often with Real-time computing constraints Today, OS-9 is a product name used by both a Motorola 68000-series machine language OS and a portable (PowerPC, x86, etc. The Motorola 68000 is a 16/32-bit CISC Microprocessor core designed and marketed by Freescale Semiconductor (formerly Motorola Semiconductor Machine code or machine language is a system of instructions and data executed directly by a Computer 's Central processing unit. PowerPC is a RISC Instruction set architecture created by the 1991 Apple – IBM – Motorola alliance known as AIM See also X86 assembly language The generic term x86 refers to the most commercially successful Instruction set architecture in the history of Personal ) version written in C, originally known as OS-9000. tags please moot on the talk page first! --> In Computing, C is a general-purpose cross-platform block structured

Contents 1 History 2 Technology 2.1 Modern and archaic design 2.2 Task scheduling 2.3 Kernel modules 3 Comparisons with Unix 4 21st century uses 5 Trivia/Easter Eggs 6 External links

History

The first version ("OS-9 Level One") , which dates back to 1979-80, was written in assembly language for the Motorola 6809 CPU, and provided a single 64 KB address space in which all processes ran. See the terminology section below for information regarding inconsistent use of the terms assembly and assembler The Motorola 6809 is an 8-bit (arguably an 8/ 16-bit) Microprocessor CPU from Motorola, introduced circa 1979 It was developed as a supporting operating system for the BASIC09 project, contracted for by Motorola as part of the 6809 development. BASIC09 is a structured BASIC programming language dialect developed by Microware for the then-new Motorola 6809 CPU. A later 6809 version ("Level Two") takes advantage of memory mapping hardware, supported up to 2 MiB of memory (ca 1980) in most implementations, and included a GUI on some platforms. A mebibyte (a contraction of me ga bi nary byte) is a unit of Information or Computer storage, abbreviated MiB.

In 1983, OS-9/6809 was ported to Motorola 68000 assembly language and extended (called OS-9/68K); and a still later (1989) version was rewritten mostly in C for further portability. Year 1983 ( MCMLXXXIII) was a Common year starting on Saturday (link displays the 1983 Gregorian calendar) The Motorola 68000 is a 16/32-bit CISC Microprocessor core designed and marketed by Freescale Semiconductor (formerly Motorola Semiconductor tags please moot on the talk page first! --> In Computing, C is a general-purpose cross-platform block structured The portable version was initially called OS-9000 and was released for 80386 PC systems around 1989, then ported to PowerPC around 1995. PowerPC is a RISC Instruction set architecture created by the 1991 Apple – IBM – Motorola alliance known as AIM Year 1995 ( MCMXCV) was a Common year starting on Sunday. Events of 1995 These later versions lack the memory mapping facilities of OS-9/6809 Level Two simply because they do not need them. They used a single flat address space that all processes share; memory mapping hardware, if present, is mostly used to ensure that processes access only that memory they have the right to access. The 680x0 and 80386 (and later) MPUs all directly support far more than 1 MiB of memory in any case.

As a consequence of early pervasive design decisions reflecting the easily used reentrant code capabilities of the 6809 processor, programs intended for OS-9 use reentrant code exclusively. OS-9 also uses position independent code and data because the 6809 also supported it directly. In Computing, position-independent code ( PIC) or position-independent executable ( PIE) is machine instruction code that executes properly The OS-9 kernel loads programs (including shared code), and allocates data, wherever sufficient free space is available in the memory map. This allows the entire OS and all applications to be placed in ROM or Flash memory, and eases memory management requirements when programs are loaded into RAM and run. Programs, device drivers, and I/O managers under OS-9 are all 'modules' and can be dynamically loaded and unloaded (subject to link counts) as needed.

OS-9/6809 ran on Motorola EXORbus systems using the Motorola 6809, SS-50 and SS-50C bus systems from companies such as SWTPC, Tano, Gimix, Midwest Scientific, and Smoke Signal Broadcasting, STD-bus 6809 systems from several suppliers, personal computers such as the Fujitsu FM-11, FM-7 and FM-77, and many others. The Motorola 6809 is an 8-bit (arguably an 8/ 16-bit) Microprocessor CPU from Motorola, introduced circa 1979 The US company SWTPC started in 1964 as DEMCO (Daniel E Meyer Company is a Japanese company specializing in Semiconductors Computers ( Supercomputers Personal computers, servers, Telecommunications FM-7 ( Fujitsu Micro 7 is a Home computer released in 1982 in Japan.

The best known hardware (due to its low price and broad distribution) was the TRS-80 Color Computer (CoCo) and its clones such as the British Dragon series. The Radio Shack TRS-80 Color Computer (also called Tandy Color Computer, or CoCo) was a Home computer launched in 1980 The Radio Shack TRS-80 Color Computer (also called Tandy Color Computer, or CoCo) was a Home computer launched in 1980 This article is about the Dragon home computers. For other uses see Dragon (disambiguation. Even on the CoCo, a quite minimalist hardware platform, it was possible under OS-9/6809 Level One to have more than one interactive user running concurrently (for example, one on the console keyboard, another in the background, and perhaps a third interactively via a serial connection) as well as several other non-interactive processes.

On a computer like an SS-50, machines which had more memory (for example, those from Gimix, Southwest Technical Products, etc. ), and I/O controllers that did not load the CPU as did the CoCo, multiple users were common, even with only 64 KB of RAM (ie, Level One). With hardware supporting memory management circuits (that is, address translation) and OS-9 Level 2, GUI use was successfully routine, even on the minimal resourced CoCo. This was several years prior to successful GUIs on the 16-bit IBM PC class machines, and many years prior to properly working multi-tasking, multi-user, access-controlled operating systems on IBM PC type machines or on any of Apple's machines.

OS-9's multi-user and multi-tasking capabilities make it usable as a general-purpose interactive computer system. Many third-party interactive applications have been written for it, such as the Dynacalc spreadsheet, the VED text formatter, and the Stylograph and Screditor-3 WYSIWYG word processors. A spreadsheet is a Computer application that simulates a paper worksheet WYSIWYG (ˈwɪziwɪg or /ˈwɪzɪwɪg/ is an Acronym for W hat Y ou S ee I s W hat Y ou G TSC's nroff emulating formatter was ported to OS-9 by MicroWay, as well. nroff (short for "new Roff " is a Unix Text-formatting program; it produces output suitable for simple fixed-width printers

In mid 1980s, OS-9 was elected for the CD-i operating system. CD-i or Compact Disc Interactive is the name of an interactive multimedia CD player developed and marketed by Royal Philips Electronics N Around the same time, Microsoft approached Microware for acquisition of the company primarily because it was attracted by CD-RTOS, the CD-i operating system. Microsoft Corporation is an American multinational Computer technology Corporation, which rose to dominate the Home computer The negotiation failed and no deal was made; Microware decided to go independently.

In late 1980s, Microware released OS-9000, a more portable version of the operating system. The vast majority of the operating system kernel was rewritten in C leaving a handful of hardware-dependent parts in assembly language. tags please moot on the talk page first! --> In Computing, C is a general-purpose cross-platform block structured A few "more advanced features" were added such as tree-like kernel module name space. OS-9000 was initially ported to the Motorola 680x0 family CPUs, Intel 80386, and PowerPC. The Motorola 680x0 / m68k / 68k / 68K is a family of 32-bit CISC Microprocessor CPU chips and was the primary PowerPC is a RISC Instruction set architecture created by the 1991 Apple – IBM – Motorola alliance known as AIM The OS-9000/680x0 was a marketing failure and withdrawn very quickly probably because few customers wanted to try the fatter and slower operating system over the existing OS-9/680x0 accompanying proven records of stability. The facts that the Motorola 680x0 family and VME board computers are nearing their end of life might affect the unpopularity of OS-9000/680x0. Microware later started calling all of its operating systems including what had been originally called OS-9000 simply OS-9 and started shifting its business interest towards portable consumer device markets such as cellphones, car navigation, and multimedia.

In late 1980s and early 1990s - the Character Generators computers used in Broadcast Systems used OS-9 and OS-9000 extensively. The now defunct Pesa Electronica used OS-9 on their CGs such as CG 4722 and CG4733.

In 1999, nineteen years after the first release of OS-9, Apple Computer released Mac OS 9. Apple Inc, ( formerly Apple Computer Inc, is an American Multinational corporation with a focus on designing and manufacturing Consumer electronics Mac OS 9 is the final major release of Apple's "Classic" Mac OS. Microware sued Apple that year for trademark infringement, although a judge ruled that there would be little chance for confusion between the two. Some Macintosh users who are unaware of Microware's relatively unknown OS-9 have been known to occasionally post to the news://comp.os.os9 newsgroup; not realising what OS-9 is.

Technology

Modern and archaic design

OS-9 (especially the 68K version and thereafter) clearly distinguishes itself from the prior generation of embedded operating systems in many aspects.

• Runs on 32-bit CPUs.
• Clear separation between user mode and supervisor (kernel) mode.
• Dynamic use of individually and separately built software components (executable program images and kernel modules) rather than a statically linked single monolithic image.
• Unix-like process name-space model (not memory model) and user shell program.
• Clear separation between hardware independent (e. g. file managers) and hardware dependent (e. g. device drivers) layers.

When compared with more modern operating systems such as Linux, however, OS-9 lacks many features used extensively in today's applications. Linux (commonly pronounced ˈlɪnəks

• Kernel is entirely written in assembly language (OS-9/68K) using rather rigid and simple internal data structures resulting in limited features and not-so-great performance.
• Systems without MMU have no memory protection against illegal accesses.
• User processes are single-threaded.
• A small set of inter-process communication tools; initially, only signals and data modules were available. Inter-Process Communication ( IPC) is a set of techniques for the exchange of data among two or more threads in one or more processes. Semaphores (called "events") were added later.

Task scheduling

(The discussion herein is based on OS-9/68K V2. x. Other versions may differ. )

Strictly speaking, OS-9 is a very soft real-time operating system for many reasons.

• Kernel code is not preemptible
• Tasks (processes) are scheduled based on priorities with aging. Each process has its age initialized with the given priority value. The process scheduler lets a runnable process with the highest age value run. When a process is given a CPU time slice, its age value is decremented by one. When a process's age value reaches zero, the age value is re-initialized with the priority value. Processes with the same age value are chosen in a round-robin manner. The term round-robin describes correspondence to a single Address authored or signed by numerous individuals (as found in a Petition)
• No treatment for priority inversion. In scheduling, priority inversion is the scenario where a low priority Task holds a shared resource that is required by a high priority task
• Most element lookups are simple linear table searches, resulting O(n) latencies.
• Interrupt services are monolithic. No provision for separation between immediate (top-half) and deferred (bottom half) services.

Kernel modules

Comparisons with Unix

OS-9's notion of processes and I/O paths is quite similar to that of Unix in nearly all respects, but there are some significant differences:

• The file system is not a single tree, but instead is a forest with each tree corresponding to a device. In Computing, a file system (often also written as filesystem) is a method for storing and organizing Computer files and the data they contain to make
• OS-9 does not have a Unix-style fork() system call--instead it has a system call which creates a process running a specified program, performing much the same function as a fork-exec or a spawn. In Computing, when a process forks, it creates a copy of itself which is called a " child process. Fork-exec is a commonly used technique in Unix whereby an executing process spawns a new program Spawn is a function that loads and executes a new Child process in the Microsoft Windows line of Operating systems The current process
• OS-9 processes keep track of two "current directories" rather than just one; the "current execution directory" is where it will by default look first to load programs to run (which is of course similar to the use of PATH environment variable under UNIX). Environment variables are a set of dynamic values that can affect the way running processes will behave on a computer
• OS-9 has had a modular design from the beginning, influenced by notions of the designers of the 6809 and how they expected software would be distributed in the future (see the three-part series of articles in Jan-Mar 1979 Byte by Terry Ritter, et al of Motorola who designed the CPU). The Motorola 6809 is an 8-bit (arguably an 8/ 16-bit) Microprocessor CPU from Motorola, introduced circa 1979 Byte magazine was an influential Microcomputer magazine in the late 1970s and throughout the 1980s because of its wide-ranging editorial coverage

The module structure requires more explanation:

• OS-9 keeps a "module directory", a memory-resident list of all modules that are in memory either by having been loaded, or by having been found in ROM during an initial scan at boot time.
• When one types a command to the OS-9 shell, it will look first in the current module directory for a module of the specified name and will use it (and increase its link count) if found, or it will look on disk for an appropriately named file if not.
• In OS-9/6809 and OS-9/68000, the module directory is flat, but OS-9000 made the module directory tree-structured. The OS-9000 shell looks in one's alternate module directory for a MODPATH environment variable, analogous to the PATH variable in all versions, indicating the sequence of module directories in which to look for pre-loaded modules.
• Modules are not only used to hold programs, but can also be created on the fly to hold data, and are the way in which OS-9 supports shared memory.

• OS-9/non-68000 supports POSIX threads. POSIX Threads is a POSIX standard for threads The standard defines an API for creating and manipulating threads A single process can start any number of threads.

21st century uses

• Versions of OS-9/68K run on a wide variety of 68000 family platforms, including the Sharp X68000 in Japan, some personal computers intended by their designers as upgrades from the Color Computer (e. The Motorola 680x0 / m68k / 68k / 68K is a family of 32-bit CISC Microprocessor CPU chips and was the primary The Sharp X68000, often referred to as the X68k, is a home computer released only in Japan by the Sharp Corporation. g. , the 68070 and 68340-based MM/1, and on other computers from Frank Hogg Laboratories, PEP, and Delmar Co. ) It was also ported to the Atari ST by Recc-o-ware in the early 1990s, and was distributed by Cumana in Europe. The Atari ST is a home / Personal computer that was commercially available from 1985 to the early 1990s A port to the Amiga is also purported to exist. The Amiga is a family of Personal computers originally developed by Amiga Corporation.

• OS-9/68K is also found in some embedded applications, including the Quanta Delta television broadcast character generator, still in production by ScanLine Technologies in Utah. While the user-level interface code on this system started at boot time, there was a hidden, undocumented keyboard sequence that would provide a user with a root shell prompt in a scroll window on the device's edit-channel monitor.

• In the embedded market, where OS-9 has found application in such devices as the Fairlight CMI synthesizers, robotics, in-car navigation systems, and Philips' Compact Disc-Interactive (CD-i) industry standard. Fairlight is a digital audio company based in Sydney Australia. Koninklijke Philips Electronics NV ( Royal Philips Electronics Inc. CD-i or Compact Disc Interactive is the name of an interactive multimedia CD player developed and marketed by Royal Philips Electronics N

• The TRS-80 Color Computer (and clones) still has users and an annual conference in Chicago; as of 2007 the 17th Annual "Last" Chicago CoCoFest is scheduled for April 2008. The Radio Shack TRS-80 Color Computer (also called Tandy Color Computer, or CoCo) was a Home computer launched in 1980 Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. A group of Canadian programmers rewrote OS-9/6809 Level II for the CoCo 3 (w/ address translation hardware) for efficiency, and to take advantage of the native mode of the Hitachi 6309. The term native mode is used in Computing in two related senses The 6309 is Hitachi's CMOS version of the Motorola 6809 Microprocessor. Today's serious CoCo users now typically have replaced the 68B09E in the CoCo 3 with an Hitachi 63B09E and run the rewrite, called NitrOS9. The combination is surprisingly fast, considering that it runs on an expressly low cost, 8-bit computer system.

• OS-9000/80x86 can be run on PC-type machines built around the Intel x86 CPUs. OS-9000 has also been ported to the PowerPC, MIPS, some versions of Advanced RISC Machines' ARM processor, and some of the Hitachi SH family of processors. PowerPC is a RISC Instruction set architecture created by the 1991 Apple – IBM – Motorola alliance known as AIM MIPS (originally an acronym for Microprocessor without Interlocked Pipeline Stages) is a RISC microprocessor architecture developed by MIPS Technologies The ARM architecture (previously the Advanced RISC Machine, and prior to that Acorn RISC Machine) is a 32-bit RISC processor architecture The SuperH (or SH) is brandname of a certain Microcontroller and Microprocessor architecture

• The DigiCart/II Plus audio playback unit runs OS-9/68K. It is a solid state replacement for radio station style cart players. This is an article about the 8-track cartridge For eight-track multitracking see Multitrack recording. These units are used in radio and at places like Walt Disney World where they play park announcements.

Trivia/Easter Eggs

The OS-9 version 2. 4 manual had this entry describing UNIX in the Glossary of Appendix C of "Using Professional OS-9":

UNIX:
An operating system similar to OS-9, but with less functionality and 
special features designed to soak up excess memory, disk space and CPU 
time on large, expensive computers. Unix (officially trademarked as UNIX, sometimes also written as Unix with Small caps) is a computer  

This entry was, curiously, removed in the version 3. 0 manual.

The OS-9 shell had an easter egg in its command history function, invoked by CTRL-A. A virtual Easter egg is an intentional Hidden message or feature in an object such as a movie, Book Command history is a common feature in operating system shells (such as Korn shell, Bash, Cmd Upon a fresh boot, the command history was supposedly empty, but if the user typed a single space followed by a backspace, then hit CTRL-A, the names of the authors would be displayed: 'by K. Kaplan, L. Crane, R. Doggett'.

External links

• Microware and Microware OS-9], from the RadiSys website
• Archive of OS-9 information and software, including an OS-9 FAQ, from Real-time Services Inc.
• Index of OS-9 resources from the Open Directory Project
• Repository for command line tools for manipulating 6809 OS-9 disk images, on SourceForge
• Execution environment for OS-9 user-mode programs on Mac/Win/linux host OS
• NitrOS-9 official website, on SourceForge
• An OS-9 Port to the Thomson MO5
• comp.os.os9 newsgroup via Google groups web interface. The Open Directory Project ( ODP) also known as dmoz (from directory SourceForgenet is a Source code repository. It acts as a centralized location for software developers to control and manage open source software development SourceForgenet is a Source code repository. It acts as a centralized location for software developers to control and manage open source software development
• Official OS-9 Blog
• A 6809 Emulator based on the SWTPC 6809 system that runs OS9 and UniFLEX as well as FLEX

---

© 2009 citizendia.org; parts available under the terms of GNU Free Documentation License, from http://en.wikipedia.org
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic