TOSkäyttöjärjestelmä

TOSkäyttöjärjestelmä, often shortened to TOS, is a proprietary operating system developed by Atari Corporation for their Atari ST line of personal computers. Released in 1985, TOS was designed to compete with systems like the Apple Macintosh and the Amiga. It featured a graphical user interface (GUI) known as GEM (Graphics Environment Manager), which was licensed from Digital Research.

The user interface of TOS presented a desktop metaphor with icons, windows, and a mouse-driven interaction model. This made it a more accessible alternative to command-line interfaces prevalent on many other computers of the era. Underneath the GEM GUI, TOS provided a multitasking kernel, although it was not fully preemptive. The operating system supported various file systems, including FAT for compatibility with MS-DOS.

Key features of TOS included a built-in command-line interpreter for more advanced users and system utilities. It also supported a range of peripherals through its various ports, such as MIDI, serial, and parallel ports. The operating system's sound and graphics capabilities were a significant part of the Atari ST's appeal, and TOS was instrumental in managing these resources.

Over its lifespan, TOS underwent several revisions, with later versions incorporating more features and bug fixes. The operating system's architecture influenced subsequent developments and is still of interest to retrocomputing enthusiasts today. While no longer actively developed by Atari, TOS has seen continued support and enhancement through fan-made projects and community efforts, allowing it to run on emulators and even modern hardware.