OS-9 Frequently Asked Questions List

Updated April 27, 1995

What is OS-9?

OS-9 is a real-time, multiuser, multitasking operating system developed by Microware Systems Corporation. It provides synchronization and mutual exclusion primitives in the form of events, which are similar to semaphores. It also allows communication between processes in the form of named and unnamed pipes, as well as shared memory in the form of data modules.

OS-9 is modular, allowing new devices to be added to the system simply by writing new device drivers, or if a similar device already exists, by simply creating a new device descriptor. All I/O devices can be treated as files, which unifies the I/O system. In addition, the kernel and all user programs are ROMable. Thus, OS-9 can run on any 680x0 based hardware platform from simple diskless embedded control systems to large multiuser minicomputers.

Originally developed for the 6809 microprocessor, OS-9 was a joint effort between Microware and Motorola. The original version of OS-9 (OS-9 Level I) was capable of addressing 64 kilobytes of memory. OS-9 Level II took advantage of dynamic address translation hardware, and allowed a mapped address space of one megabyte on most systems, and up to two megabytes on others, most notably the Tandy Color Computer 3.

In the 1980's, Microware ported OS-9 to the 68000 family of microprocessors, creating OS-9/68000, which is used in a variety of industrial and commercial arenas, including Philips' CD-i. Code is mostly portable from OS-9/6809 to OS-9/68000 at the high-level language source code level. Code is compatible within either OS-9/6809 or OS-9/68000 at the binary level.

Where can I get OS-9?

Generally, a hardware vendor of a particular computer system will ship a version of OS-9 for their platform. In addition, several software vendors sell customized and enhanced OS-9 packages, and Microware sells single license copies for certain systems.

What machines run OS-9?

OS-9/68000 runs on a multitude of machines, including a variety of systems from Hazelwood (such as the UniQuad I and II), the GMX EISA, the Atari ST, Commodore Amiga, Apple Macintosh, BlackHawk Enterprises' (formerly IMS) MM/1, FHL TC-70, and a large number of 680x0-based VME systems, manufactured by such companies as Radstone Technology, Motorola, Heurikon, Inducom, Force, Mizar, ELSOFT, PEP Modular Computers, and others. Gespac also makes a large number of platforms based on their G-64 and G-96 bus.

OS-9/6809 runs on a variety of platforms, perhaps the most (in)famous being the Tandy Color Computer. Other systems include the SWTPC SCB-69, the Gimix 6809, Smoke Signal Broadcasting's Chieftain 6809, FHL's TC-9, the Febe, and a host of others, most of which are SS-50 bus machines. Note that OS-9/6809 is no longer supported by Microware, but many user groups, BBSes, and a handful of FTP sites offer help and maintain software collections for OS-9/6809.

What is DAVID?

DAVID is a configuration of OS-9/OS-9000 targeted towards the Interactive TV Set Top Box (STB) market. DAVID stands for Digital Audio Video Interactive Decoder. The unique characteristics of DAVID are that it will always include the following IO subsystems: Like all OS-9 systems, DAVID may be expanded with any other file managers, but these are considered the base case set.

DAVID has been shipping for the Motorola 68xxx family for over one year (currently v1.1). This summer it will be updated to v2.0 and shipped for 68xxx, Power PC and 80x86 processor families.

Where do I get OS-9/68000 for the Macintosh?

Ultrascience (A division of Gibbs Laboratories) makes a version of OS-9/68000 for the Macintosh. According to their literature, it even allows the Macintosh operating system to run as a process under OS-9.

Where do I get OS-9/68000 for the Commodore Amiga?

Digby Tarvin from Australia, has a port of OS-9/68000 for the Amiga, which costs approximately $600 US.

Where do I get OS-9/68000 for the Atari ST?

Dr. Keil offers a port of OS-9 to the ST. Cumana, however, recently stopped the business with OS-9 for the Atari because they did not sell enough packages. Cumana OS-9 therefore is no longer supported or sold.

What is OS-9000?

OS-9000 is a portable version of OS-9, written primarily in C. It can potentially run on any 680x0 family member, and any 80386 or higher. Code is portable across OS-9000 platforms at the source level. Theoretically, OS-9000 can be ported to any modern computer architecture. Currently the 80386/486 and Pentium are supported, with a port to the PowerPC in development.

What software is available for OS-9?

Nearly any user application can be found either commercially or in the public domain/shareware/freeware. Many word-processor, spreadsheets, databases, and time management software packages are available from a variety of vendors. A list of much of the available commercial software is available from Microware. They publish the "OS-9 Sourcebook", a listing of hardware and software vendors who sell both 6809 and 68000 software and hardware. It is advisable to contact the individual companies listed in the Sourcebook and request a recent catalog, as the information in the Sourcebook is a tad outdated. Microware's quarterly magazine Pipelines also carries new product announcements.

Where can I get public-domain/shareware/freeware software for OS-9?

There are many private bulletin boards around. Hopefully, someone will be publishing a list of all known BBSes which have OS-9 software. The OS-9 International Magazine publishes a list of BBSes and FTP sites in each issue, subject to update from its readership. In addition, there is the Princeton Listserver, which acts as a mailing server that will mail requested software. To begin using the Listserver, send electronic mail to listserv@pucc.princeton.edu, with the word HELP in your message. Also, both the OS-9 Users Group, Inc. and EFFO maintain a library of public domain software, as well as distributes a newsletter. Finally, there are a few anonymous FTP servers worldwide with OS-9 software on them.

Don't forget the often overlooked mailserver on chestnut. The e-mail address is os9archive@chestnut.cs.wisc.edu, and a message with "help" as the body will return some help text. This provides a way for those without FTP access to snarf stuff from chestnut via mail.

Chestnut contains mostly OS-9/68000 software, including the complete TOP package, many EFFO disks, GCC and G++, (and many other GNU products such as flex and bison), ka9q, k5jb, TeX, LaTeX, and quite a bit of 6809 software.

Wuarchive has mostly 6809 OS-9 software; Lucy is meant to be a European duplicate of chestnut.

Where can I get online information about OS-9?

There are several newsgroups and mailing lists on the internet which discuss OS-9 and its derivatives. On Usenet NetNews, the following groups cover OS-9, the first of which more so than the others:

CompuServe and Delphi both have OS-9 forums with a files section for downloads of some of the latest OS-9/68000 and OS-9/6809 shareware. On-line conferences are regularly scheduled on Delphi's OS-9 forum on a variety of topics. GEnie also has OS-9 support with OSK files found in a section of the Atari ST RoundTable and CoCo OS-9 and MM/1 files found in the Tandy RoundTable.

Also, the Princeton Listserver carries a discussion forum for the Tandy Color Computer and its derivatives, which often includes discussion of OS-9/6809. To get information about the listserver, send e-mail to listserv@pucc.princeton.edu, with the word HELP as the body of the message. The listserver also maintains a file collection of CoCo software.

Finally, fatcat@zog.wa.com is a mailing list of OS-9 related discussions. To subscribe to this list, simply send mail to:

with the email body

Public Messages should be sent to:

Messages sent to this account are "re-broadcast" to the list.

What is the OS-9 Users Group?

The OS-9 Users Group, Inc. is a non-profit organization based in the United States. In addition to maintaining a library of OS-9 software, it distributes the MOTD newsletter to its members and is currently working on various methods of supporting personal and industrial OS-9 users. Click here for the OS-9 Users Group FAQ, where more detailed information is available.

What is the TOP package?

TOP is an acronym for "The OS-9 Project". It is a collection of OS-9/68000 software developed primarily in Germany and available through ftp on chestnut.cs.wisc.edu. Much of it seems to be an attempt to make OS-9 a little more UNIX-like. Many standard UNIX utilities are provided, as well as a complete UUCP mail implementation, and a more secure password file and login program. Many traditional UNIX games are also provided. The total package consumes approximately 16 MB of disk space, though much of this is source code.

What is the EFFO?

EFFO, The European Forum For OS-9 maintains a large library of PD Software for OS-9,e.g. the new C-Kermit 5A, an improved KA9Q Software called SLIP for OSK, Ghostscript and many other fine products. The software is available at a nominal handling fee, including a written instruction or even a complete users manual.

Are there any independent magazines covering OS-9?

Currently there are two magazines which cover OS-9 topics: International OS-9 Underground Magazine and OS-9 International as the official publication of EFFO. Both magazines are written in English.

What books are available that cover OS-9 topics?

Here is a listing of currently available books.

Are there alternative shells for OS-9?

Yes, there are. Microware sells MShell, an enhanced shell. In addition, there are several public domain shells available. The most notable of which is the Bourne shell, sh, available in the TOP package (OS-9/68000) in its original version. A newer version with may enhancements and bug fixes is available through EFFO. sh supports aliasing, command-line editing, history, environment variable replacement, shell scripting, the `command` operator (which uses the output of the command as arguments to the called program), and a startup file. For users feeling at home in a VAX/VMS surrounding, the zsh shell is commercially available from ELSOFT.

A PD version of ksh is available on chestnut. Bash, the GNU shell, has also recently been ported. Bash is available on chestnut.cs.wisc.edu

For OS-9/6809, there is Shell+ and if you have a Color Computer 3, there is always GShell a graphical shell.

Can one read/write MS-DOS format disks under OS-9?

Yes, there are several public-domain and commercially avaliable utilities to accomplish this task, for both OS-9/6809 and OSK. One of the more interesting is the MSFM file manager which appears in OS-9 Insights, a book by Peter Dibble, available through Microware. MSFM is an actual file manager, which allows you to mount an MS-DOS floppy as part of the OS-9 file system.

What communications software is available?

Many public domain utilities, available from your local BBS, include terminal emulators and file transfer utilities (such as xmodem, ymodem, zmodem, and kermit protocols.) Sterm, a non-commercial package, also supports Compuserve B+ protocol. In addition, many software vendors sell various equivalent packages. C-kermit is available in source and executable form for OS-9/68000 on chestnut.cs.wisc.edu.

Also, Microware sells the NFM Network File Manager, which is a local-area networking protocol for small networks of strictly OS-9 based computers. NFM runs on virtually any network interface, including direct serial links, ARCnet, Ethernet, and others.

Microware also sells the ISP, or Internet Support Package, which is a relatively complete TCP/IP package, including telnet client and server applications, and FTP client and server. It also provides a C BSD 4.2 compatible socket library. Closely related is the ESP, or Ethernet Support Package. This is similar to ISP, but is for particular Ethernet boards. Current word from Microware says that the ESP is now obsolete, and has been replaced by a preconfigured version of the ISP. ISP supports Ethernet and SLIP.

Microware also sells NFS, or Network File System, for OS-9/68000. This allows an OS-9 system to share files in a heterogeneous environment (i.e. not all the machines on the network run OS-9.) NFS requires ISP or ESP.

There is a port of the Phil Karn ka9q internet software package, which supports a single-user interface to TCP/IP. It includes a telnet client, an FTP client and server, and SMTP. Source and executables may be found on chestnut. Note that the executables on chestnut have a bug in the FTP server which causes it to bus trap occasionally. The newer k5jb code should correct this. (The author of this FAQ has not had a chance to test the newer software yet.)

EKF Elektronik sells, in addition to the Microware networking software, two additional networking protocols:

For more information on these products, you can contact Gerald Nimmrich at EKF (gn@ekf.werries.de).

PEP Modular Computers provides the following network protocols:

What about usenet and news?

Several ports of UUCP software are available for both OS-9/6809 and OS-9/68K. A port of C news and RN are available on chestnut.cs.wisc.edu. TOP has ported Notes, which maintains Notesfiles. There is a program which will transfer between Notesfiles and netnews. The TOP package in its entirety may be found on chestnut.

Rick Adams' UUCP port for OS-9/6809 is also available, and this has been updated to UUCPbb by Bob Billson and others. UUCPbb is also available for OS-9/68000 and may be found on wuarchive and chestnut, as well as on Delphi and CompuServe. A nice companion mail reader for this package called Palm, which has Elm-like features, is also available. UUCPbb features:

Click here to ftp UUCPbb and Palm.

Elm has also been ported to OSK, and is available on chestnut. The Elm package is a port of elm 2.4; it fits in the rmail/lmail/uucp environment that can be found in the TOP package.

For more information on Elm, contact Harold Groene.

Is GCC available for OS-9?

GCC and g++ are available for OS-9/68000, both in OS-9 executable form and cross-compiler form. Version 1.37 was ported to OS-9 by Atsushi Seyama and was then supported and updated to the version 1.39, 1.40, and 1.42.2 by Stephan Paschedag. Source and binaries are available on chestnut.cs.wisc.edu via anonymous FTP. The 1.40 versions and up support 68040 optimizations. Version 2.x of GCC is a completely new port to OS-9 which allows better optimization. The first version that was released was version 2.4.5 which is available on chestnut.cs.wisc.edu in /pub/OSK/GCC/BIN/gcc_2.4.5_cmds.lzh. The current edition (V2.5.8) includes a new I/O library which gives full compatibility with C++ programs (I/O streams). It also supports the different calling interfaces of Microware's compilers (cc V3.x and UltraC). Version 2.6.x of GCC and G++ is expected for the end of 1994. Bear in mind that the newer editions (2.x) will require at least 4 MB of memory free in order to run.

Can I run X11 on OS-9?

Yes. Microware sells a port of X11R5 (client and server plus optional Motif). Eltec Electronik GmbH sells an X11R4 port.

Kei Thomsen has also done a port of X11R5 and X11R6. His port requires Microware sockets, GCC 2.x, OS9lib.l (unix compatibility routines), and a bourne shell for running imake. It requires a minimum of 4 MB physical memory, 8MB if you plan to run any applications. To quote Kei:

What other graphics alternatives are there?

Several other organizations have various graphics packages for OS-9. Reccoware Systems has a port of the Bellcore MGR window manager. Gespac produces G-Windows, a portable windowing package which has device windows and a very Motif-looking interface. For the MM/1, BlackHawk Enterprises sells KWindows, a window manager similar to the Multi-Vue OS-9 window package for the Tandy Color Computer 3. Microware also sells RAVE, the Real-Time Audio Video Environment.

What is a Real Time system?

A real-time system is any system whose correctness depends not only on the correctness of the applied algorithms, but also in the timing of the execution of those algorithms. Refer to the netnews comp.realtime newsgroup for more information.

Does OS-9 support multiple threads within a program?

No, not directly like Mach does, but through the use of user installed periodic interrupts or alarms, a user program can support it's own threads. Consult a good operating systems book for more details.

OS-9 Business Index

Microware Systems Corporation



BlackHawk Enterprises

Inducom Systems BV

PEP Modular Computers



Gespac S.A.

Heurikon Corporation

Digby Tarvin, Technical Director

Dr. R. Keil GmbH

OS-9 Users Group, Inc.

EFFO & OS-9 International

The "International" OS-9 Underground

EKF Elektronik GmbH

Harold Groene

Eltec Electronik GmbH

Galactic Industrial

Kei Thomsen

Reccoware Systems

Windsor Consulting Group

The OS-9 FAQ WWW Page is currently maintained by Boisy G. Pitre. Please send any changes or corrections to boisy@microware.com