Web site: www.microware.com
Origin: USA
Category: Workstation
Desktop environment: CLI
Architecture: Motorola 6809/680×0, ColdFire, SuperH, ARM, MIPS, PowerPC, x86
Based on: Independent
Wikipedia: OS-9
Media: Install
The last version | Released: 6.1 | November 14, 2017
OS-9 (or: OS9) – an operating system created in 1980 by Microware for computers based on the Motorola 6809 processor. It was purchased by Radisys Corp in 2001, and then sold in 2013 to Microware LP.
The system was then implemented in 1983 on computers with processors from the Motorola 68000 family. In 1989, the system kernel was rewritten from assembler to C (for better portability) and the system was implemented on Intel 80386 and PowerPC processors, initially under the name OS-9000.
OS-9 is a multi-user system (a unique feature among computers based on 8-bit microprocessors), optimized for use in real-time systems. The system kernel is very compact, in the original version for the 6809 processor it was 4 KB, and the input/output subsystem is highly modular, only the modules necessary to support the devices present in the system are loaded. The entire system can be placed in ROM, so that a computer with this system does not require external mass storage to start and load the system. Thanks to the consistent use of modularity and multi-threaded code, the system was able to function even with very small RAM. The file system structure is somewhat similar to that of UNIX, but each physical device is the root of its own directory tree.
Today, OS-9 is still used, primarily as an embedded system in various devices. It is also used by hobbyists; versions of OS-9 were implemented on TRS-80 and Atari ST computers, among others.
When Apple released another version of its operating system in 1999, called MAC OS 9, Microware filed a lawsuit for infringement of its trademark. However, the court found that the probability of confusion between the two products was low and dismissed the lawsuit.
