TOS Overview
The/Tramiel Operating System (TOS) was the graphical operating system used on Atari's 16/32-bit computers, including the ST, STE, TT, and Falcon series. It included the GEM (Graphical Environment Manager) for its GUI and evolved over time with various disk-based and ROM-based releases.
Disk-Based TOS Versions
TOS 1.0 (Disk-Based)
The first release of TOS was disk-based and shipped with early models of the Atari 260ST before being transferred to ROM.
ROM-Based TOS Versions
TOS 1.0
The first ROM version of TOS, found in the 520ST and early 1040ST models, was stable but had some bugs and lacked hard drive support.
TOS 1.02 ("Blitter TOS")
Released with the later ST models, including the 520STFM and 1040STFM. It included minor improvements and bug fixes.
TOS 1.04 ("Rainbow TOS")
This version was a significant update, improving GEM performance, fixing numerous bugs, and enhancing hard disk compatibility.
TOS 1.06 / TOS 1.62
These versions were developed for the STE series, adding blitter and DMA sound support while improving memory handling.
TOS 2.06
The final TOS for ST and STE models, featuring a new desktop layout, better file management, and increased compatibility.
TOS 3.0x / 3.05 / 3.06
TOS 3.0x: The initial version of TOS for the Atari TT, offering basic support for the TT’s expanded capabilities.
TOS 3.05: Improved stability and compatibility with software designed for high-resolution TT screens.
TOS 3.06: The final version for the TT series, featuring improved memory management and bug fixes.
Used exclusively on the Atari TT, this version supported higher resolutions, improved multitasking, and enhanced memory management.
TOS 4.0 / 4.01 / 4.02 / 4.04
TOS 4.0: The original Falcon 030 release, adding full VGA support and DSP integration.
TOS 4.01: Minor bug fixes and enhancements to improve system stability.
TOS 4.02: Improved hard disk compatibility and additional system optimizations.
TOS 4.04: The final official release, refining Falcon performance and enhancing MultiTOS support.
Developed for the Falcon 030, featuring VGA support, advanced audio handling, and a more modernized interface.
MultiTOS and MiNT
MultiTOS
MultiTOS was an attempt by Atari to introduce multitasking capabilities to its computers. It was bundled with later versions of TOS but suffered from performance issues due to the lack of memory protection and the limitations of the Motorola 68000 processor.
MiNT (Before Atari's Involvement)
MiNT ("MiNT is Not TOS") started as a third-party UNIX-like multitasking system for the Atari ST series. It was designed to bring better multitasking to TOS without requiring major hardware changes.
MiNT (After Atari's Involvement)
Atari later adopted MiNT ("MiNT is Now TOS") as its official multitasking kernel, integrating it with MultiTOS to improve performance and compatibility. This led to further enhancements but was ultimately abandoned after Atari exited the computer market.
UMTOS
UMTOS (Unix-like MultiTOS) was a further development of Atari’s MultiTOS, intended to improve multitasking capabilities on later hardware. It was never widely adopted but remains an interesting part of Atari’s software evolution.
EmuTOS
EmuTOS is an open-source replacement for Atari's TOS, developed to run on original Atari hardware as well as emulators. It maintains compatibility with TOS applications while introducing modern enhancements such as larger partition support and better hardware compatibility.
Legacy
TOS played a crucial role in making Atari computers viable for business, gaming, and music production. Although it was eventually surpassed by modern operating systems, its legacy lives on in retro computing communities, with projects like EmuTOS ensuring continued compatibility for Atari systems.