(
The
Operating
System)
Atari TOS is the operating system released in 1995 by Atari for its 16/32 bits computer series.
At first, Atari had licenced both
CP/M 68k (lower layer operating system) and
GEM (upper layer graphical extension) from Digital Research Inc. As
CP/M 68k proved to be too slow when accessing floppy disks, Atari decided to write its own lower layer from scratch,
GEMDOS based on the next and faster operating system standard, i.e.
MS-DOS. This is why
GEMDOS can read and write on
MS-DOS FAT? filesystems (FAT12 floppy disks, FAT16 hard drives). However a driver is still needed to safely read and write FAT32 partitions, and handle long file names (LFN)
This mixture of
GEM by Digital Research and
GEMDOS by Atari was named
TOS, for Tramiel Operating System, and later became
The Operating System.
Below
GEMDOS, Atari also wrote
BIOS and
XBIOS responsible for dealing with Atari hardware. Within the higher layer of
TOS, Digital Research had already divided
GEM into a lower layer called
VDI and a higher one, built on the latter and called
AES. See the
TOS Design section for an in-depth discussion of
TOS architecture.
Between 1985 and 1995, many
TOS versions were released, shipping different versions of the embedded system layers (
GEMDOS,
VDI,
AES). These
TOS versions are discussed and listed in a separate article.
See Also