<s>
The	O
IBM	B-Device
2250	I-Device
Graphics	I-Device
Display	I-Device
Unit	I-Device
was	O
a	O
vector	O
graphics	O
display	O
system	O
by	O
IBM	O
for	O
the	O
System/360	B-Application
;	O
the	O
Model	O
IV	O
attached	O
to	O
the	O
IBM	B-Device
1130	I-Device
.	O
</s>
<s>
The	O
IBM	B-Device
2250	I-Device
Graphics	I-Device
Display	I-Device
Unit	I-Device
was	O
announced	O
with	O
System/360	B-Application
in	O
1964	O
.	O
</s>
<s>
A	O
display	O
list	O
of	O
line	O
segments	O
(	O
vectors	O
)	O
on	O
a	O
1024	O
by	O
1024	O
grid	O
was	O
stored	O
in	O
computer	O
's	O
memory	O
or	O
an	O
optional	O
buffer	O
on	O
the	O
2250	O
and	O
repainted	O
on	O
the	O
2250	O
's	O
CRT	B-Device
up	O
to	O
40	O
times	O
per	O
second	O
.	O
</s>
<s>
The	O
2250	O
was	O
housed	O
in	O
a	O
desk	O
with	O
an	O
alphanumeric	O
(	O
QWERTY	O
)	O
keyboard	B-Device
and	O
a	O
separate	O
programmed	O
function	O
keyboard	B-Device
which	O
had	O
keys	O
,	O
indicator	O
lights	O
and	O
switches	O
.	O
</s>
<s>
A	O
plastic	O
overlay	O
label	O
could	O
be	O
placed	O
over	O
the	O
function	O
keyboard	B-Device
.	O
</s>
<s>
The	O
2250s	O
CRT	B-Device
measured	O
21	O
"	O
diagonal	O
,	O
but	O
the	O
useful	O
display	O
area	O
was	O
12inch	O
by	O
12inch	O
.	O
</s>
<s>
A	O
light	B-Device
pen	I-Device
was	O
provided	O
as	O
a	O
pointing	B-Device
device	I-Device
,	O
serving	O
the	O
function	O
of	O
the	O
modern	O
computer	B-Device
mouse	I-Device
.	O
</s>
<s>
Model	O
1	O
–	O
attached	O
directly	O
to	O
a	O
System/360	B-Application
via	O
a	O
selector	O
or	O
multiplexor	O
channel	O
.	O
</s>
<s>
Model	O
4	O
–	O
attached	O
to	O
an	O
IBM	B-Device
1130	I-Device
minicomputer	O
via	O
the	O
storage	O
access	O
channel	O
(	O
SAC	O
)	O
.	O
</s>
<s>
The	O
1130	O
could	O
run	O
either	O
as	O
a	O
standalone	O
processor	O
or	O
as	O
a	O
front-end	O
processor	O
connected	O
to	O
a	O
remote	O
System/360	B-Application
.	O
</s>
<s>
A	O
number	O
of	O
plug	B-Device
compatible	I-Device
manufacturers	I-Device
sold	O
competitors	O
to	O
the	O
2250	O
,	O
including	O
Adage	O
,	O
Evans	O
&	O
Sutherland	O
,	O
Information	O
Displays	O
Inc.	O
,	O
Lundy	O
,	O
Sanders	O
,	O
Spectragraphics	O
,	O
and	O
Vector	B-Application
General	I-Application
.	O
</s>
