<s>
TOS	B-Application
(	O
The	O
Operating	B-General_Concept
System	I-General_Concept
)	O
is	O
the	O
operating	B-General_Concept
system	I-General_Concept
of	O
the	O
Atari	B-Device
ST	I-Device
range	O
of	O
computers	O
.	O
</s>
<s>
This	O
range	O
includes	O
the	O
520ST	O
and	O
1040ST	B-Device
,	O
their	O
STF/M/FM	O
and	O
STE	O
variants	O
and	O
the	O
Mega	O
ST/STE	O
.	O
</s>
<s>
Later	O
,	O
32-bit	O
machines	O
(	O
TT	B-Device
,	O
Falcon030	B-Device
)	O
were	O
developed	O
using	O
a	O
new	O
version	O
of	O
TOS	B-Application
,	O
called	O
MultiTOS	B-Application
,	O
which	O
allowed	O
multitasking	B-Operating_System
.	O
</s>
<s>
More	O
recently	O
,	O
users	O
have	O
further	O
developed	O
TOS	B-Application
into	O
FreeMiNT	B-Application
.	O
</s>
<s>
Atari	B-Application
TOS	I-Application
(	O
The	O
Operating	B-General_Concept
System	I-General_Concept
)	O
debuted	O
with	O
the	O
Atari	B-Device
520ST	I-Device
in	O
1985	O
.	O
</s>
<s>
TOS	B-Application
combines	O
Digital	O
Research	O
's	O
GEM	B-Application
GUI	I-Application
running	O
on	O
top	O
of	O
the	O
DOS-like	O
GEMDOS	B-Operating_System
.	O
</s>
<s>
Features	O
include	O
a	O
flat	B-General_Concept
memory	I-General_Concept
model	I-General_Concept
,	O
DOS-compatible	O
disk	O
format	O
(	O
starting	O
with	O
TOS	B-Application
1.04	I-Application
)	O
,	O
support	O
for	O
MIDI	O
,	O
and	O
a	O
variant	O
of	O
SCSI	B-Architecture
called	O
ACSI	O
in	O
later	O
versions	O
.	O
</s>
<s>
Atari	O
's	O
TOS	B-Application
is	O
usually	O
run	O
from	O
ROM	B-Device
chips	I-Device
contained	O
in	O
the	O
computer	O
:	O
Thus	O
,	O
before	O
local	O
hard	O
drives	O
were	O
available	O
in	O
home	O
computers	O
,	O
it	O
was	O
an	O
almost	O
instant-running	O
OS	O
.	O
</s>
<s>
TOS	B-Application
booted	O
off	O
floppy	O
disks	O
in	O
the	O
very	O
first	O
STs	O
,	O
but	O
only	O
about	O
half	O
a	O
year	O
after	O
the	O
ST	O
was	O
introduced	O
,	O
all	O
ST	O
models	O
started	O
shipping	O
with	O
the	O
latest	O
version	O
of	O
TOS	B-Application
in	O
ROM	B-Device
.	O
</s>
<s>
TOS	B-Application
consisted	O
of	O
the	O
following	O
:	O
</s>
<s>
The	O
following	O
were	O
extensions	O
to	O
TOS	B-Application
(	O
loaded	O
separately	O
)	O
:	O
</s>
<s>
True	O
multitasking	B-Operating_System
was	O
not	O
directly	O
supported	O
,	O
but	O
TOS	B-Application
allowed	O
up	O
to	O
six	O
desk	O
accessories	O
to	O
be	O
loaded	O
into	O
the	O
system	O
,	O
which	O
are	O
similar	O
to	O
terminate-and-stay-resident	O
programs	O
on	O
PCs	O
.	O
</s>
<s>
MultiTOS	B-Application
was	O
developed	O
to	O
allow	O
TOS	B-Application
to	O
preemptively	O
multitask	O
.	O
</s>
<s>
The	O
TOS	B-Application
desktop	O
uses	O
icons	O
to	O
represent	O
files	O
and	O
devices	O
,	O
windows	O
and	O
dialog	O
boxes	O
to	O
display	O
info	O
.	O
</s>
<s>
Executable	B-Application
files	I-Application
are	O
identified	O
by	O
their	O
extensions	O
:	O
</s>
<s>
*	O
.ACC	B-Application
–	O
Desktop	O
accessory	O
.	O
</s>
<s>
*	O
.APP	B-Application
–	O
Application	O
(	O
rarely	O
encountered	O
)	O
.	O
</s>
<s>
*	O
.PRG	O
–	O
Executable	B-Application
program	I-Application
.	O
</s>
<s>
Can	O
be	O
GEM	B-Application
programs	O
.	O
</s>
<s>
*	O
.TOS	O
–	O
"	O
TOS	B-Application
"	O
program	O
that	O
does	O
n't	O
use	O
GEM	B-Application
—	O
i.e.	O
,	O
similar	O
to	O
a	O
PC	O
's	O
.EXE	O
or	O
.COM	O
running	O
in	O
a	O
CLI-mode	O
box	O
.	O
</s>
<s>
The	O
desktop	O
clears	O
the	O
screen	O
,	O
turns	O
on	O
the	O
text	B-Application
cursor	I-Application
,	O
and	O
hides	O
the	O
mouse	B-Device
pointer	O
.	O
</s>
<s>
*	O
.TTP	O
–	O
"	O
TOS	B-Application
takes	O
parameters	O
"	O
.	O
</s>
<s>
*	O
.GTP	O
–	O
"	O
GEM	B-Application
takes	O
parameters	O
"	O
.	O
</s>
<s>
TOS	B-Application
programs	O
(	O
but	O
not	O
GEM	B-Application
programs	O
)	O
can	O
auto	O
boot	O
by	O
placing	O
them	O
in	O
a	O
folder	O
named	O
"	O
AUTO	O
"	O
.	O
</s>
<s>
TOS	B-Application
1.4	O
allows	O
GEM	B-Application
programs	O
to	O
be	O
set	O
to	O
load	O
automatically	O
from	O
the	O
"	O
Install	O
Application	O
"	O
dialog	O
.	O
</s>
<s>
Atari	B-Application
TOS	I-Application
is	O
based	O
on	O
GEMDOS	B-Operating_System
which	O
uses	O
a	O
modified	O
FAT12	B-Application
(	O
or	O
,	O
on	O
hard	O
disks	O
,	O
FAT16	B-Application
)	O
file	O
system	O
.	O
</s>
<s>
The	O
major	O
differences	O
are	O
the	O
fact	O
that	O
the	O
boot	O
sector	O
does	O
not	O
need	O
to	O
contain	O
the	O
IBM	O
compatible	O
jump	O
sequence	O
at	O
the	O
beginning	O
(	O
typically	O
or	O
)	O
,	O
the	O
lack	O
(	O
before	O
TOS	B-Application
1.04	I-Application
)	O
of	O
an	O
OEM	O
identifier	O
compatible	O
with	O
PC-based	O
systems	O
,	O
and	O
the	O
fact	O
that	O
a	O
checksum	O
is	O
used	O
to	O
mark	O
the	O
boot	O
sector	O
as	O
executable	B-Application
(	O
the	O
PC	O
format	O
uses	O
the	O
signature	O
word	O
instead	O
)	O
.	O
</s>
<s>
Executable	B-Application
boot	O
sectors	O
for	O
the	O
Atari	O
platform	O
typically	O
start	O
with	O
an	O
MC68K	O
jump	O
opcode	O
(	O
e.g.	O
</s>
<s>
Unlike	O
MS-DOS	O
,	O
GEMDOS	B-Operating_System
would	O
typically	O
allow	O
disks	O
with	O
unusual	O
sector	O
and	O
track	O
counts	O
,	O
so	O
disks	O
with	O
10	O
or	O
even	O
11	O
sectors	O
per	O
track	O
and	O
over	O
80	O
formatted	O
tracks	O
were	O
not	O
uncommon	O
in	O
the	O
Atari	O
community	O
.	O
</s>
<s>
GEMDOS	B-Operating_System
disc	O
file	O
systems	O
can	O
be	O
read	O
using	O
DOS	B-Device
or	O
Windows	O
9x	O
.	O
</s>
<s>
1.0	O
(	O
ROM	B-Device
TOS	B-Application
)	O
Earliest	O
version	O
released	O
on	O
disk	O
.	O
</s>
<s>
First	O
ROM	B-Device
release	O
of	O
TOS	B-Application
.	O
</s>
<s>
1.02	O
(	O
MEGA	O
TOS	B-Application
)	O
fixed	O
bugs	B-Application
,	O
supported	O
Blitter	B-General_Concept
co-processor	O
and	O
real-time	O
clock	O
.	O
</s>
<s>
1.04	O
(	O
RAINBOW	O
TOS	B-Application
)	O
Many	O
bug	B-Application
fixes	O
,	O
file	O
selector	O
changed	O
,	O
DOS-compatible	O
disk	O
formatting	O
,	O
much	O
improved	O
performance	O
.	O
</s>
<s>
1.06	O
(	O
STE	O
TOS	B-Application
,	O
Revision	O
1	O
)	O
Support	O
for	O
STe	O
machines	O
only	O
.	O
</s>
<s>
Needed	O
STE_FIX.PRG	O
to	O
patch	O
bugs	B-Application
.	O
</s>
<s>
1.62	O
(	O
STE	O
TOS	B-Application
,	O
Revision	O
2	O
)	O
bug	B-Application
fixes	O
for	O
the	O
previous	O
1.06	O
STE	O
TOS	B-Application
.	O
</s>
<s>
2.02	O
Early	O
TOS	B-Application
release	O
for	O
Mega	O
STE	O
.	O
</s>
<s>
2.05	O
(	O
Mega	O
STE	O
TOS	B-Application
)	O
Only	O
found	O
in	O
the	O
Mega	O
STE	O
with	O
720K	O
floppy	O
drive	O
.	O
</s>
<s>
2.06	O
(	O
ST/STE	O
TOS	B-Application
)	O
Last	O
TOS	B-Application
version	O
for	O
ST/STE	O
computers	O
.	O
</s>
<s>
Bug	B-Application
fixes	O
,	O
1.44	O
MB	O
disk	O
support	O
,	O
memory	O
test	O
.	O
</s>
<s>
Adds	O
GTP	O
program	O
support	O
(	O
GEM-Takes-Parameters	O
)	O
.	O
</s>
<s>
Greatly	O
enhanced	O
GEM	B-Application
GUI	I-Application
.	O
</s>
<s>
2.08	O
used	O
in	O
notebook	O
ST	O
.	O
ROM	B-Device
also	O
contains	O
some	O
notebook-specific	O
utilities	O
:	O
STTRANS	O
(	O
null-modem/	O
parallel-cable	O
data	O
transfer	O
)	O
,	O
power	O
management	O
tools	O
,	O
hard	O
disk	O
drive	O
tools	O
and	O
drivers	O
(	O
AHDI	O
,	O
XHDI	O
,	O
BOOKINST	O
and	O
BOOKFMT	O
)	O
and	O
a	O
RAMdisk	O
installer	O
.	O
</s>
<s>
3.01	O
,	O
3.05	O
,	O
3.06	O
(	O
TT	B-Device
TOS	B-Application
)	O
Primarily	O
for	O
68030	O
TT	B-Device
support	O
only	O
.	O
</s>
<s>
Supports	O
fast	O
"	O
TT	B-Device
RAM	O
"	O
,	O
special	O
TT	B-Device
screen	O
resolutions	O
etc	O
.	O
</s>
<s>
ST-hardware-compatible	O
"	O
Line-A	O
"	O
API	O
dropped	O
for	O
extended	O
TT	B-Device
functionality	O
,	O
forcing	O
programmers	O
to	O
use	O
GEM-compliant	O
VDI	O
calls	O
etc	O
.	O
</s>
<s>
and	O
thus	O
encouraging	O
GEM-compatible	O
(	O
as	O
opposed	O
to	O
ST-compatible	O
)	O
development	O
.	O
</s>
<s>
Adds	O
support	O
for	O
DSP	O
,	O
16MHz	O
blitter	B-General_Concept
and	O
video	O
overlay	O
.	O
</s>
<s>
New	O
v3.40	O
AES	O
(	O
last	O
single-tasking	O
version	O
,	O
but	O
MiNT/MultiTOS	O
-multitasking-aware	O
)	O
supports	O
:	O
pop-up	O
menus	O
,	O
3D	O
window	O
and	O
dialog	O
objects	O
(	O
later	O
modified	O
to	O
use	O
more	O
compatible	O
ob_state	O
flags	O
instead	O
of	O
extended	O
type	O
)	O
,	O
256-colour	O
"	O
animated	O
"	O
icons	O
,	O
soft-loaded	O
fonts	O
,	O
inter-app	O
drag&drop	O
,	O
background	O
window	O
manipulation	O
,	O
extensible	O
filesystems	O
.	O
</s>
<s>
V4.04	O
was	O
the	O
last	O
official	O
Atari	O
version	O
of	O
TOS	B-Application
.	O
</s>
<s>
4.08	O
(	O
512KB	O
)	O
Developed	O
and	O
released	O
by	O
Milan	O
Computersysteme	O
for	O
the	O
Milan	O
,	O
a	O
68040/60	O
TOS/GEM	O
computer	O
.	O
</s>
<s>
TOS	B-Application
4.92	O
was	O
a	O
version	O
of	O
MultiTOS	B-Application
,	O
the	O
multitasking	B-Operating_System
version	O
of	O
TOS	B-Application
,	O
in	O
a	O
format	O
(	O
.IMG	O
)	O
designed	O
to	O
be	O
written	O
to	O
a	O
ROM	B-Device
chip	I-Device
.	O
</s>
<s>
TOS	B-Application
4	O
ROM	B-Device
contains	O
five	O
user-selectable	O
language	O
versions	O
.	O
</s>
