Atari TOS

The Operating System (TOS) [ [http://groups.google.com/group/comp.sys.atari.st/browse_thread/thread/3574f55f26957e64 About the meaning of TOS] According to a wide-spread rumour, TOS initially meant "Tramiel" Operating System" from the name of Atari Corp. President Jack Tramiel.] is the operating system of the Atari ST range of computers. This range includes the 520ST, 1040ST and the F, FM and E variations (e.g.1040STE). Later, 32-bit machines (TT, Falcon030) were developed using a new version of "TOS", called MultiTOS, which allowed multitasking. More recently, users have developed TOS further into FreeMiNT.

Details

The Atari TOS 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, MS-DOS-compatible disk format, support for MIDI, and a variant of SCSI called ACSI in later versions. Atari's TOS is 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 originally booted off floppy disks but later ST models came with the latest version of TOS in ROM. [http://xaaes.atariforge.net/]

"TOS" consisted of the following:
*Desktop - The main interface loaded after bootup.
*GEM - Graphical Environment Manager
**AES - Application Environment Service
**VDI - Virtual Device Interface (screen drivers only, other drivers loaded using GDOS)
*GEMDOS - GEM Disk Operating System
*BIOS - Basic Input/Output System
*XBIOS - Xtended BIOS
*Line-A - Low-level high-speed graphics calls. Obsolete

The following were extensions to "TOS" (loaded separately):
*GDOS - Graphics Device Operation System
*AHDI - Atari Hard Disk Interface (driver for Hard Drive)

True multitasking was not directly supported, "TOS" allows desk accessories to be loaded into the system which are similar to TSRs (Terminate and Stay Resident) on PCs (up to a maximum of six) and could co-operatively multitask. MultiTOS was developed to allow "TOS" to preemptively multitask.

Desktop

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:
* *.ACC - Desktop accessory. Automatically loaded.
* *.APP - Application (not common).
* *.PRG - Executable program. Can be GEM programs.
* *.TOS - "TOS" program that doesn't use GEM. The desktop clears the screen, turns on the text cursor and hides the mouse cursor.
* *.TTP - "TOS takes parameters". This opens a dialog box where arguments can be added for the program. However, it converts characters to uppercase.

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.

Versions

TOS 1

*1.0 (ROM TOS) Earliest version released on disk. First ROM release of TOS.
** Formats: floppy, 2 chip and 6 chip ROMs (192 KB)
** Rom date: 20 Nov 1985
** Machines: 520ST, 1040ST
*1.02 (MEGA TOS) fixed bugs, supported Blitter co-processor and real-time clock.
** Formats: 2 chip and 6 chip ROMs (192 KB)
** Rom date: 22 Apr 1987
** Machines: 520ST, 1040ST, Mega 2, Mega 4
*1.04 (RAINBOW TOS) Many bug fixes, file selector changed, DOS-compatible disk formatting, much improved performance. However, compatibility problems with older software.
** Formats: 2 chip and 6 chip ROMs (192 KB)
** Rom date: 6 Apr 1989
** Machines: 520ST, 1040ST, Mega 2, Mega 4, Stacy
*1.06 (STE TOS, Revision 1) Support for STe machines only. Needed STE_FIX.PRG to patch bugs.
** Format: 2 chip ROMs (256 KB)
** Rom date: 29 Jul 1989
** Machines: 520STE, 1040 STE
*1.62 (STE TOS, Revision 2) bug fixes for the previous 1.06 STE TOS.
** Format: 2 chip ROMs (256 KB)
** Rom date: 1 Jan 1990
** Machines: 520STE, 1040 STE

TOS 2

*2.02 Early TOS release for Mega STE.
*2.05 (Mega STE TOS) Only found in the Mega STE with 720K floppy drive.
** Format: 2 chip ROMs (256 KB)
** Rom date: 5 Dec 1990
** Machines: Mega STE
*2.06 (ST/STE TOS) Bug fixes, 1.44 MB disk support, memory test. Greatly enhanced GEM GUI. IDE hard disk booting. Last TOS version for ST/STE computers.
** Format: 2 chip ROMs (256 KB)
** Rom date: 14 Nov 1991
** Machines: 520ST, 1040ST, 520STE, 1040STE
*2.07 used on the Falcon prototype "FX-1"
*2.08 used in notebook ST.

TOS 3

*3.01, 3.05, 3.06 (TT TOS) Primarily for 68030 TT support only.
** Format: 4 chip ROMs (512 KB)

TOS 4

*4.00, 4.01, 4.02, 4.04 (512 KB) Update for Falcon 030 machines only.
*4.92 Last TOS version, was never officially released

TOS 4 ROM contains five, user-selectable language versions.

See also

* EmuTOS
* Multitasking versions of "TOS"
** MiNT
** MultiTOS
* GEM

References

External links

* [http://www.atari.st/content.php?type=t&file=toslist Town's Guide to TOS Revisions]
* [http://osis.nocrew.org/otosis/ TOS/MiNT emulator]
* [http://www.vintagecomputercafe.com/atarisystemdisks.htm Atari ST System Disks]
* [http://jens-inge.dyndns.org/html/guide206/index.htm TOS 2.06 Guide] - User's guide
* [http://www.fortunecity.com/skyscraper/apple/308/ Atari Compendium] - Reference guide for Atari ST programming. "Recommended"
* [http://www.nabrozidis.com GEM based site]