Atari TOS
operating system of the Atari ST range of computers
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.
Details
Atari TOS (The Operating System) debuted with the Atari 520ST in 1985. TOS combines Digital Research's GEM GUI running on top of 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.
TOS consisted of the following:
Desktop – The main interface loaded after bootup.
GEM – Graphics Environment Manager, licensed from Digital Research
AES – Application Environment Services
VDI – Virtual Device Interface (screen drivers only, other drivers loaded using GDOS)
GEMDOS – GEM Disk Operating System
BIOS – Basic Input/Output System
XBIOS – Extended BIOS
Line-A – Low-level high-speed graphics calls. Obsolete from TOS 3 onwards.
The following were extensions to TOS (loaded separately):
GDOS – Graphics Device Operating System
AHDI – Atari Hard Disk Interface (hard disk driver)
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
The TOS desktop uses icons to represent files and devices, windows and dialog boxes to display info.
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