<s>
The	O
Burroughs	B-Device
AN/GSA	I-Device
-51	I-Device
Radar	I-Device
Course	I-Device
Directing	I-Device
Group	I-Device
was	O
a	O
United	O
States	O
Air	O
Force	O
air	O
defense	O
command	O
,	O
control	O
,	O
and	O
coordination	O
system	O
,	O
part	O
of	O
the	O
Semi-Automatic	B-Device
Ground	I-Device
Environment	I-Device
system	O
.	O
</s>
<s>
It	O
was	O
intended	O
to	O
replace	O
vacuum	O
tube	O
IBM	B-Device
AN/FSQ	I-Device
-7	I-Device
Combat	I-Device
Direction	I-Device
Centrals	I-Device
.	O
</s>
