<s>
A	O
Windows	B-Device
accelerator	I-Device
was	O
a	O
type	O
of	O
Graphics	B-Architecture
processing	I-Architecture
unit	I-Architecture
for	O
personal	B-Device
computers	I-Device
with	O
additional	O
acceleration	O
features	O
like	O
2D	O
line-drawings	O
,	O
blitter	B-General_Concept
,	O
clipping	B-Algorithm
,	O
font	O
caching	O
,	O
hardware	O
cursor	O
support	O
,	O
color	O
expansion	O
,	O
linear	B-General_Concept
addressing	I-General_Concept
,	O
and	O
pattern	O
,	O
polygon	O
and	O
area	O
fills	O
.	O
</s>
<s>
The	O
functionality	O
marketed	O
for	O
accelerating	B-General_Concept
the	O
Microsoft	B-Application
Windows	I-Application
operating	I-Application
system	I-Application
.	O
</s>
<s>
These	O
have	O
been	O
superseded	O
by	O
multipurpose	O
GPUs	B-Architecture
which	O
include	O
acceleration	O
for	O
3D	O
graphics	O
.	O
</s>
<s>
Most	O
of	O
the	O
Windows	B-Device
accelerator	I-Device
video	B-Device
cards	I-Device
were	O
2D	O
capable	O
fixed	O
function	O
accelerators	O
that	O
got	O
2D	O
drawing	O
commands	O
and	O
pixel	O
data	O
sent	O
from	O
the	O
CPU	B-General_Concept
and	O
the	O
fixed	O
function	O
run	O
the	O
given	O
command	O
which	O
resulted	O
in	O
a	O
faster	O
drawing	O
of	O
the	O
window	O
.	O
</s>
<s>
The	O
lessened	O
burden	O
on	O
the	O
CPU	B-General_Concept
,	O
combined	O
with	O
the	O
smaller	O
data	B-General_Concept
stream	I-General_Concept
needed	O
for	O
the	O
required	O
instructions	O
,	O
resulted	O
in	O
improved	O
performance	O
compared	O
to	O
dumb	O
frame-buffer	O
only	O
based	O
video-cards	O
.	O
</s>
<s>
In	O
the	O
high-end	O
professional	O
area	O
a	O
price	O
of	O
several	O
thousands	O
of	O
dollars	O
,	O
there	O
were	O
also	O
coprocessor	O
based	O
video	O
chipsets	O
like	O
the	O
Texas	B-General_Concept
Instrument	I-General_Concept
TMS34020	I-General_Concept
available	O
that	O
had	O
their	O
own	O
processor	O
which	O
allowed	O
to	O
offload	O
some	O
of	O
the	O
processing	O
data	O
from	O
the	O
CPU	B-General_Concept
to	O
the	O
coprocessor	O
the	O
videocard	B-Device
.	O
</s>
<s>
To	O
make	O
use	O
of	O
these	O
accelerator	O
or	O
coprocessor	O
based	O
video	B-Device
cards	I-Device
,	O
a	O
Windows	O
Graphic	O
driver	O
for	O
the	O
specific	O
video	O
chipset	O
was	O
necessary	O
.	O
</s>
