<s>
In	O
computing	O
,	O
the	O
icon	B-Device
bar	I-Device
is	O
the	O
name	O
of	O
the	O
dock	O
in	O
Acorn	O
's	O
RISC	B-Operating_System
OS	I-Operating_System
operating	B-General_Concept
system	I-General_Concept
,	O
and	O
is	O
fundamental	O
to	O
the	O
OS	O
.	O
</s>
<s>
Its	O
introduction	O
in	O
1987	O
(	O
as	O
part	O
of	O
Arthur	O
,	O
the	O
predecessor	O
to	O
)	O
was	O
a	O
new	O
concept	O
in	O
GUIs	B-Application
.	O
</s>
<s>
It	O
displays	O
icons	O
through	O
which	O
access	O
is	O
provided	O
to	O
all	O
parts	O
of	O
the	O
computer	O
that	O
a	O
typical	O
user	O
will	O
require	O
,	O
from	O
physical	O
devices	O
and	O
system	O
utilities	O
to	O
running	O
applications	O
,	O
and	O
will	O
usually	O
be	O
their	O
starting	O
point	O
for	O
interacting	O
with	O
the	O
system	O
once	O
it	O
has	O
finished	O
booting	B-Operating_System
.	O
</s>
<s>
According	O
to	O
Acorn	O
's	O
official	O
RISC	B-Operating_System
OS	I-Operating_System
Style	O
Guide	O
,	O
a	O
program	O
should	O
place	O
its	O
icons	O
to	O
the	O
left	O
hand	O
side	O
of	O
the	O
icon	B-Device
bar	I-Device
if	O
they	O
relate	O
to	O
physical	O
devices	O
or	O
resources	O
such	O
as	O
filing	B-Application
systems	I-Application
.	O
</s>
<s>
If	O
too	O
many	O
icons	O
are	O
present	O
to	O
be	O
displayed	O
at	O
once	O
then	O
the	O
icon	B-Device
bar	I-Device
will	O
extend	O
horizontally	O
and	O
become	O
wider	O
than	O
the	O
screen	O
;	O
in	O
order	O
to	O
access	O
the	O
non-visible	O
icons	O
the	O
user	O
must	O
scroll	O
the	O
bar	O
by	O
hovering	O
the	O
mouse	O
pointer	O
at	O
the	O
appropriate	O
edge	O
of	O
the	O
screen	O
.	O
</s>
<s>
For	O
filing	B-Application
systems	I-Application
,	O
a	O
filer	O
window	O
will	O
open	O
containing	O
the	O
contents	O
of	O
the	O
root	O
directory	O
.	O
</s>
<s>
This	O
is	O
different	O
from	O
the	O
behaviour	O
of	O
the	O
typical	O
Taskbar	O
and	O
Dock	O
,	O
where	O
clicking	O
an	O
icon	O
will	O
result	O
in	O
a	O
task	B-Operating_System
switch	I-Operating_System
(	O
All	O
windows	O
associated	O
with	O
the	O
icon	O
will	O
be	O
brought	O
to	O
the	O
front	O
of	O
the	O
window	O
stack	O
and	O
will	O
gain	O
input	B-Application
focus	I-Application
)	O
.	O
</s>
<s>
For	O
programs	O
that	O
do	O
not	O
support	O
multiple	O
open	O
documents	O
,	O
clicking	O
its	O
icon	O
will	O
typically	O
result	O
in	O
the	O
task	B-Operating_System
switch	I-Operating_System
behaviour	O
.	O
</s>
<s>
By	O
pressing	O
the	O
middle	O
(	O
Menu	O
)	O
mouse	O
button	O
while	O
the	O
pointer	O
is	O
over	O
an	O
icon	O
,	O
a	O
context-sensitive	B-Application
menu	I-Application
associated	O
with	O
that	O
icon	O
will	O
open	O
.	O
</s>
<s>
For	O
example	O
,	O
filing	B-Application
systems	I-Application
will	O
allow	O
the	O
naming	O
and	O
formatting	O
of	O
disks	O
,	O
as	O
well	O
as	O
an	O
option	O
to	O
open	O
a	O
window	O
displaying	O
free	O
space	O
.	O
</s>
<s>
Most	O
applications	O
will	O
provide	O
access	O
to	O
an	O
Info	O
window	O
(	O
displaying	O
the	O
version	O
number	O
and	O
copyright	O
information	O
)	O
,	O
online	B-Protocol
help	I-Protocol
,	O
and	O
a	O
quit	O
option	O
.	O
</s>
<s>
Drag	O
and	O
Drop	O
,	O
Filer	O
Icons	O
(	O
File	O
or	O
Directory	O
)	O
can	O
be	O
dragged	O
and	O
dropped	O
on	O
top	O
of	O
an	O
icon	B-Device
bar	I-Device
icon	O
to	O
initiate	O
a	O
process	O
,	O
if	O
the	O
object	O
type	O
is	O
known	O
to	O
the	O
application	O
.	O
</s>
<s>
Even	O
if	O
there	O
are	O
no	O
running	O
applications	O
or	O
active	O
filing	B-Application
systems	I-Application
,	O
the	O
icon	B-Device
bar	I-Device
will	O
contain	O
a	O
small	O
number	O
of	O
system-managed	O
icons	O
:	O
</s>
<s>
This	O
was	O
introduced	O
in	O
RISC	B-Operating_System
OS	I-Operating_System
3	O
as	O
a	O
way	O
to	O
access	O
the	O
applications	O
built	O
into	O
the	O
computer	O
's	O
ROM	B-Device
.	O
</s>
<s>
Although	O
ResourceFS	O
is	O
read-only	O
via	O
the	O
usual	O
filing	O
system	O
interface	O
,	O
system	O
APIs	B-Application
can	O
be	O
used	O
to	O
add	O
or	O
replace	O
files	O
.	O
</s>
<s>
In	O
RISC	B-Operating_System
OS	I-Operating_System
3.5	O
this	O
functionality	O
was	O
leveraged	O
to	O
allow	O
the	O
user	O
to	O
easily	O
add	O
his	O
own	O
applications	O
to	O
the	O
Apps	O
folder	O
,	O
via	O
the	O
AddApp	O
star	O
command	O
.	O
</s>
<s>
This	O
allows	O
the	O
applications	O
to	O
be	O
added	O
without	O
using	O
significant	O
amounts	O
of	O
RAM	B-Architecture
and	O
restricting	O
them	O
to	O
read-only	O
access	O
to	O
their	O
internal	O
files	O
.	O
</s>
<s>
The	O
Task	O
Manager	O
icon	O
,	O
located	O
to	O
the	O
far	O
right	O
of	O
the	O
icon	B-Device
bar	I-Device
.	O
</s>
<s>
From	O
the	O
task	O
manager	O
's	O
icon	B-Device
bar	I-Device
menu	O
it	O
is	O
also	O
possible	O
to	O
shut	O
down	O
the	O
computer	O
,	O
exit	O
the	O
window	O
manager	O
to	O
the	O
single-tasking	O
CLI	B-Application
,	O
or	O
open	O
a	O
multi-tasking	O
CLI	B-Application
window	O
.	O
</s>
<s>
A	O
desktop	O
boot	B-Operating_System
file	O
can	O
also	O
be	O
saved	O
,	O
which	O
contains	O
the	O
current	O
state	O
of	O
the	O
desktop	O
and	O
any	O
loaded	O
programs	O
.	O
</s>
<s>
In	O
theory	O
this	O
provides	O
full	O
hibernation	O
support	O
,	O
although	O
in	O
reality	O
because	O
each	O
program	O
is	O
responsible	O
for	O
saving	O
and	O
restoring	O
its	O
state	O
within	O
the	O
file	O
,	O
the	O
computer	O
's	O
state	O
after	O
executing	O
the	O
saved	O
boot	B-Operating_System
file	O
will	O
not	O
be	O
identical	O
to	O
its	O
state	O
before	O
.	O
</s>
<s>
In	O
versions	O
of	O
RISC	B-Operating_System
OS	I-Operating_System
prior	O
to	O
3.5	O
,	O
where	O
memory	O
restrictions	O
forced	O
most	O
people	O
to	O
use	O
modes	O
with	O
16	O
or	O
less	O
colours	O
,	O
it	O
was	O
also	O
possible	O
to	O
alter	O
the	O
current	O
palette	B-Data_Structure
from	O
this	O
icon	O
.	O
</s>
<s>
In	O
RISC	B-Operating_System
OS	I-Operating_System
3	O
the	O
AddTinyDir	O
star	O
command	O
was	O
introduced	O
,	O
which	O
allows	O
an	O
icon	O
for	O
any	O
file	O
,	O
folder	O
or	O
application	O
to	O
be	O
added	O
to	O
the	O
left-hand	O
side	O
of	O
the	O
icon	B-Device
bar	I-Device
.	O
</s>
<s>
The	O
icon	B-Device
bar	I-Device
first	O
appeared	O
in	O
the	O
Arthur	O
operating	B-General_Concept
system	I-General_Concept
,	O
in	O
1987	O
.	O
</s>
<s>
To	O
the	O
right	O
was	O
an	O
Exit	O
icon	O
,	O
which	O
provided	O
an	O
exit	O
to	O
the	O
command	B-Application
line	I-Application
(	O
later	O
to	O
be	O
replaced	O
by	O
the	O
Task	O
Manager	O
)	O
.	O
</s>
<s>
RISC	B-Operating_System
OS	I-Operating_System
2	O
in	O
1988	O
introduced	O
the	O
Task	O
Manager	O
and	O
Display	O
icons	O
,	O
with	O
the	O
Task	O
Manager	O
adopting	O
Acorn	O
's	O
Archimedes	B-Device
logo	O
.	O
</s>
<s>
Amongst	O
these	O
was	O
one	O
called	O
TinyDirs	O
,	O
which	O
allowed	O
users	O
to	O
dock	O
applications	O
and	O
directories	O
on	O
the	O
icon	B-Device
bar	I-Device
for	O
convenient	O
access	O
.	O
</s>
<s>
RISC	B-Operating_System
OS	I-Operating_System
3	O
in	O
1991	O
introduced	O
the	O
Apps	O
icon	O
to	O
the	O
left	O
and	O
replaced	O
the	O
Task	O
Managers	O
Archimedes	B-Device
logo	O
with	O
the	O
Acorn	O
nut	O
.	O
</s>
<s>
Apps	O
provided	O
access	O
to	O
the	O
ROM	B-Device
based	O
applications	O
and	O
the	O
functionality	O
of	O
TinyDirs	O
was	O
replaced	O
by	O
the	O
OS	O
command	O
AddTinyDir	O
.	O
</s>
<s>
The	O
whole	O
of	O
RISC	B-Operating_System
OS	I-Operating_System
,	O
including	O
the	O
icon	B-Device
bar	I-Device
,	O
was	O
given	O
a	O
facelift	O
in	O
1993	O
including	O
replacement	O
of	O
the	O
flat	O
grey	O
colour	O
with	O
a	O
textured	O
wallpaper	O
.	O
</s>
<s>
In	O
1994	O
,	O
this	O
3D	O
look	O
was	O
provided	O
as	O
standard	O
with	O
the	O
release	O
of	O
RISC	B-Operating_System
OS	I-Operating_System
3.5	O
on	O
the	O
series	O
.	O
</s>
<s>
The	O
"	O
nested	O
Wimp	O
"	O
introduced	O
in	O
1998	O
(	O
as	O
a	O
soft	O
load	O
for	O
existing	O
machines	O
)	O
added	O
the	O
feature	O
to	O
temporarily	O
bring	O
the	O
icon	B-Device
bar	I-Device
to	O
the	O
front	O
of	O
the	O
window	O
stack	O
by	O
moving	O
the	O
pointer	O
to	O
the	O
bottom	O
of	O
the	O
screen	O
(	O
previously	O
this	O
required	O
Shift-F12	O
on	O
the	O
keyboard	O
)	O
.	O
</s>
<s>
RISC	B-Operating_System
OS	I-Operating_System
4	O
in	O
1999	O
introduced	O
the	O
facility	O
for	O
iconised	O
windows	O
to	O
be	O
sent	O
to	O
the	O
icon	B-Device
bar	I-Device
rather	O
than	O
the	O
Pinboard	O
.	O
</s>
<s>
The	O
facelift	O
introduced	O
in	O
RISC	B-Operating_System
OS	I-Operating_System
3.5	O
was	O
also	O
incorporated	O
directly	O
into	O
the	O
OS	O
,	O
as	O
well	O
as	O
the	O
method	O
of	O
popping	O
the	O
icon	B-Device
bar	I-Device
to	O
the	O
front	O
.	O
</s>
<s>
RISC	B-Operating_System
OS	I-Operating_System
5	O
in	O
2002	O
introduced	O
further	O
changes	O
in	O
icon	O
design	O
,	O
including	O
the	O
Iyonix	B-Device
'	O
blue	O
jellybean	O
 '	O
Task	O
Manager	O
icon	O
,	O
again	O
designed	O
by	O
Richard	O
Hallas	O
.	O
</s>
<s>
RISC	B-Operating_System
OS	I-Operating_System
6	O
in	O
2006	O
introduced	O
the	O
number	O
6	O
in	O
the	O
centre	O
of	O
the	O
Task	O
Managers	O
cogwheel	O
icon	O
.	O
</s>
