Atari TOS

Last updated

Atari TOS
MultiTOS.png
MultiTOS 1.0 with various programs provided by Atari in the background
Developer Atari Corporation
Working stateDiscontinued
Initial release20 November 1985;38 years ago (1985-11-20)
Latest release 4.04
Latest preview 4.92
Platforms Motorola 68000
Default
user interface
GEM
License Proprietary commercial software
Succeeded by MultiTOS

TOS (The Operating System) is the operating system of the Atari ST range of computers. This range includes the 520ST and 1040ST, their STF/M/FM and STE variants and the Mega ST/STE. Later, 32-bit machines (TT, Falcon030) were developed using a new version of TOS, called MultiTOS, which allowed multitasking. More recently, users have further developed TOS into FreeMiNT.

Contents

Details

Atari TOS (The Operating System) [1] debuted with the Atari 520ST in 1985. TOS combines Digital Research's GEM GUI running on top of the DOS-like GEMDOS. Features include a flat memory model, DOS-compatible disk format (starting with TOS 1.04), support for MIDI, and a variant of SCSI called ACSI in later versions. Atari's TOS is usually run from ROM chips contained in the computer: Thus, before local hard drives were available in home computers, it was an almost instant-running OS. TOS booted off floppy disks in the very first STs, but only about half a year after the ST was introduced, all ST models started shipping with the latest version of TOS in ROM. [2]

TOS consisted of the following:

The following were extensions to TOS (loaded separately):

True multitasking was not directly supported, but TOS allowed up to six Desk accessories to be loaded into the system. MultiTOS was developed to allow TOS to preemptively multitask.

Desktop

Atari TOS/GEM - monochrome screen TOS 1.00.png
Atari TOS/GEM - monochrome screen

The TOS desktop uses icons to represent files and devices, windows and dialog boxes to display info. The desktop file "DESKTOP.INF" was read to determine window settings, icon placements and drive icons, otherwise the standard default desktop of two floppy icons and the trash icon was used.

Later versions use "NEWDESK.INF" for saving and reading the desktop configuration.

Executable files are identified by their extensions:

TOS programs (but not GEM programs) can auto boot by placing them in a folder named "AUTO". TOS 1.4 allows GEM programs to be set to load automatically from the "Install Application" dialog. Programs with *.TTP extensions and environments can not be used for auto boot. Desktop accessories were placed in the root directory of the default drive and loaded automatically.

File system

Atari TOS is based on GEMDOS which uses a modified FAT12 (or, on hard disks, FAT16) file system. [3] The major differences are the fact that the boot sector does not need to contain the IBM compatible jump sequence at the beginning (typically 0xE9 0x?? 0x?? or 0xEB 0x?? 0x90), the lack (before TOS 1.04) of an OEM identifier compatible with PC-based systems, and the fact that a checksum is used to mark the boot sector as executable (the PC format uses the signature word 0x55 0xAA instead). Executable boot sectors for the Atari platform typically start with an MC68K jump opcode (e.g. 0x603C, and the last two byte word must sum with the rest of the boot sector (in big-endian word form) to 0x1234 in order to be bootable.

Unlike MS-DOS, GEMDOS would typically allow disks with unusual sector and track counts. As such, disks with 10 or even 11 sectors per track and over 80 formatted tracks were not uncommon in the Atari community. Typically a safe combination, such as 10 sectors per track by 80 tracks, was used, yielding an unformatted capacity of 800KB, but many users pushed the capacity of their double-density disks beyond 900KB using custom formats.

GEMDOS disc file systems can be read using DOS or Windows 9x.

Versions

TOS 1

TOS 1.04, nicknamed "Rainbow TOS" for its animated Atari logo TOS 1.04 (Rainbow TOS).png
TOS 1.04, nicknamed "Rainbow TOS" for its animated Atari logo

TOS 2

TOS 3

TOS 4

TOS 4.92 (with German language selected) Tos492.png
TOS 4.92 (with German language selected)

TOS 4.92 was a version of MultiTOS, the multitasking version of TOS, in a format (.IMG) designed to be written to a ROM chip. TOS 4 ROM contains five user-selectable language versions.

EmuTOS

EmuTOS with the built-in desktop and the desk accessory COPS EmuTOS 1.0.png
EmuTOS with the built-in desktop and the desk accessory COPS

EmuTOS is a replacement for TOS (the operating system of the Atari ST and its successors), released as a free software. [4] It runs on Atari and Amiga hardware and various emulators. [5] Its compatibility with computer video games for Atari ST is limited. [6]

See also

Row of bombs.png
"Row of bombs" error screen – 4 bombs denotes that an illegal instruction has been detected
Row of mushroom clouds.png
"Row of mushroom clouds" error screen in TOS version 1.0 – 20 bombs denotes that an unspecified error has occurred

Related Research Articles

<span class="mw-page-title-main">Atari ST</span> Line of home computers from Atari Corporation

Atari ST is a line of personal computers from Atari Corporation and the successor to the company's 8-bit home computers. The initial model, the Atari 520ST, had limited release in April–June 1985, and was widely available in July. It was the first personal computer with a bitmapped color graphical user interface, using a version of Digital Research's GEM interface / operating system from February 1985.

<span class="mw-page-title-main">BIOS</span> Firmware for hardware initialization and OS runtime services

In computing, BIOS is firmware used to provide runtime services for operating systems and programs and to perform hardware initialization during the booting process. The BIOS firmware comes pre-installed on an IBM PC or IBM PC compatible's system board and exists in some UEFI-based systems to maintain compatibility with operating systems that do not support UEFI native operation. The name originates from the Basic Input/Output System used in the CP/M operating system in 1975. The BIOS originally proprietary to the IBM PC has been reverse engineered by some companies looking to create compatible systems. The interface of that original system serves as a de facto standard.

<span class="mw-page-title-main">GEM (desktop environment)</span> Operating environment created by Digital Research

GEM is a discontinued operating environment released by Digital Research in 1985. GEM is known primarily as the native graphical user interface of the Atari ST series of computers, providing a WIMP desktop. It was also available for IBM PC compatibles and shipped with some models from Amstrad. GEM is used as the core for some commercial MS-DOS programs, the most notable being Ventura Publisher. It was ported to other computers that previously lacked graphical interfaces, but never gained traction. The final retail version of GEM was released in 1988.

<span class="mw-page-title-main">Apple ProDOS</span> Operating system on Apple II series computers

ProDOS is the name of two similar operating systems for the Apple II series of personal computers. The original ProDOS, renamed ProDOS 8 in version 1.2, is the last official operating system usable by all 8-bit Apple II series computers, and was distributed from 1983 to 1993. The other, ProDOS 16, was a stop-gap solution for the 16-bit Apple IIGS that was replaced by GS/OS within two years.

<span class="mw-page-title-main">MiNT</span> Alternative operating system kernel for Atari ST

MiNT is a free software alternative operating system kernel for the Atari ST series. It is a multi-tasking alternative to TOS and MagiC. Together with the free system components fVDI device drivers, XaAES graphical user interface widgets, and TeraDesk file manager, MiNT provides a free TOS compatible replacement OS that can multitask.

<span class="mw-page-title-main">Atari Falcon</span> 1992 personal computer

The Atari Falcon030, released in 1992, is the final personal computer from Atari Corporation. A high-end model of the Atari ST line, the machine is based on a Motorola 68030 CPU and a Motorola 56001 digital signal processor, which distinguishes it from most other microcomputers of the era. It includes a new VIDEL programmable graphics system which greatly improves graphics capabilities.

<span class="mw-page-title-main">Atari DOS</span> Operating system

Atari DOS is the disk operating system used with the Atari 8-bit computers. Operating system extensions loaded into memory were required in order for an Atari computer to manage files stored on a disk drive. These extensions to the operating system added the disk handler and other file management features.

<span class="mw-page-title-main">Atari TT030</span> Personal computer by Atari

The Atari TT030 is a member of the Atari ST family, released in 1990. It was originally intended to be a high-end Unix workstation, but Atari took two years to release a port of Unix SVR4 for the TT, which prevented the TT from ever being seriously considered in its intended market.

Timeworks Publisher was a desktop publishing (DTP) program produced by GST Software in the United Kingdom and published by Timeworks, Inc., in the United States.

<span class="mw-page-title-main">Rainbow 100</span> DEC microcomputer

The Rainbow 100 is a microcomputer introduced by Digital Equipment Corporation (DEC) in 1982. This desktop unit had a monitor similar to the VT220 and a dual-CPU box with both 4 MHz Zilog Z80 and 4.81 MHz Intel 8088 CPUs. The Rainbow 100 was a triple-use machine: VT100 mode, 8-bit CP/M mode, and CP/M-86 or MS-DOS mode using the 8088. It ultimately failed to in the marketplace which became dominated by the simpler IBM PC and its clones which established the industry standard as compatibility with CP/M became less important than IBM PC compatibility. Writer David Ahl called it a disastrous foray into the personal computer market. The Rainbow was launched along with the similarly packaged DEC Professional and DECmate II which were also not successful. The failure of DEC to gain a significant foothold in the high-volume PC market would be the beginning of the end of the computer hardware industry in New England, as nearly all computer companies located there were focused on minicomputers for large organizations, from DEC to Data General, Wang, Prime, Computervision, Honeywell, and Symbolics Inc.

<span class="mw-page-title-main">DOS Plus</span> Discontinued computer operating system for x86 processors

DOS Plus was the first operating system developed by Digital Research's OEM Support Group in Newbury, Berkshire, UK, first released in 1985. DOS Plus 1.0 was based on CP/M-86 Plus combined with the PCMODE emulator from Concurrent PC DOS 4.11. While CP/M-86 Plus and Concurrent DOS 4.1 still had been developed in the United States, Concurrent PC DOS 4.11 was an internationalized and bug-fixed version brought forward by Digital Research UK. Later DOS Plus 2.x issues were based on Concurrent PC DOS 5.0 instead. In the broader picture, DOS Plus can be seen as an intermediate step between Concurrent CP/M-86 and DR DOS.

The Atari Coldfire Project (ACP) is a volunteer project that has created a modern Atari ST computer clone called the FireBee.

<span class="mw-page-title-main">Atari MEGA STE</span> Personal computer by Atari

The Atari Mega STE is Atari Corporation's final Motorola 68000-based personal computer in the Atari ST series and the second to last model overall. Released in 1991, the Mega STE is a late-model STE mounted in the case of an Atari TT computer. It was followed by the higher end Atari Falcon in 1992.

<span class="mw-page-title-main">SpareMiNT</span> Software distribution based on FreeMiNT

SpareMiNT is a software distribution based on FreeMiNT, which consists of a MiNT-like operating system (OS) and kernel plus GEM compatible AES.

MagiC is a third party and now open-sourced multitasking-capable TOS-compatible operating system for Atari computers, including some newer clone systems manufactured later. There are also variants that run as part of Mac and PC emulation environments, as well as on macOS Intel-Mac computers.

<span class="mw-page-title-main">Kickstart (Amiga)</span> Bootstrap firmware used by Amiga computers

Kickstart is the bootstrap firmware of the Amiga computers developed by Commodore International. Its purpose is to initialize the Amiga hardware and core components of AmigaOS and then attempt to boot from a bootable volume, such as a floppy disk. Most Amiga models were shipped with the Kickstart firmware stored on ROM chips.

<span class="mw-page-title-main">SpartaDOS X</span> Disk operating system

SpartaDOS X is a disk operating system for the Atari 8-bit computers that closely resembles MS-DOS. It was developed and sold by ICD in 1987-1993, and many years later picked up by the third-party community SpartaDOS X Upgrade Project, which still maintains the software.

<span class="mw-page-title-main">DOS</span> Family of IBM PC-compatible operating systems

DOS is a family of disk-based operating systems for IBM PC compatible computers. The DOS family primarily consists of IBM PC DOS and a rebranded version, Microsoft's MS-DOS, both of which were introduced in 1981. Later compatible systems from other manufacturers include DR-DOS (1988), ROM-DOS (1989), PTS-DOS (1993), and FreeDOS (1998). MS-DOS dominated the IBM PC compatible market between 1981 and 1995.

The FAT file system is a file system used on MS-DOS and Windows 9x family of operating systems. It continues to be used on mobile devices and embedded systems, and thus is a well suited file system for data exchange between computers and devices of almost any type and age from 1981 through the present.

References

  1. Anderson, John J. (October 1985). "Atari 520ST; a reborn Atari once again points the way to the next generation". Creative Computing. p. 26. Retrieved 2011-03-17.
  2. "The Unofficial XaAES Page". Archived from the original on 2003-05-27. Retrieved 2007-07-05.
  3. alternative-system.com - Revive GEMDOS for lisa
  4. Proven, Liam (2022-12-05). "A brand new Linux DRM display driver – for a 1992 computer". The Register. Retrieved 2024-04-11.
  5. Proven, Liam (2022-08-04). "The many derivatives of the CP/M operating system". The Register. Retrieved 2024-04-11.
  6. Schwirzke, Kai (2019-03-08). "Retro-Games auf den Mac bringen". Mac & i. Retrieved 2024-04-11.