<s>
Reference	B-Device
Computer	I-Device
is	O
a	O
computerized	O
supplement	O
to	O
PBX	O
(	O
Private	B-Device
Branch	I-Device
Exchange	I-Device
or	O
PBX	O
)	O
that	O
supports	O
the	O
internal	O
telephone	O
directory	O
,	O
absence	O
data	O
and	O
messages	O
.	O
</s>
<s>
Reference	B-Device
Computer	I-Device
is	O
an	O
effective	O
aid	O
for	O
the	O
switchboard	O
operator	O
as	O
information	O
on	O
the	O
lines	O
are	O
obtained	O
directly	O
from	O
a	O
display	O
.	O
</s>
<s>
Reference	B-Device
computer	I-Device
is	O
connected	O
to	O
the	O
telephone	O
exchange	O
and	O
a	O
call	O
comes	O
in	O
to	O
an	O
extension	O
the	O
computer	O
shows	O
all	O
the	O
data	O
about	O
that	O
extension	O
automatically	O
.	O
</s>
<s>
Reference	B-Device
computer	I-Device
enabled	O
a	O
sophisticated	O
information	O
management	O
in	O
large	O
companies	O
.	O
</s>
<s>
The	O
first	O
complete	O
reference	B-Device
computer	I-Device
attached	O
to	O
PBX	O
in	O
the	O
Swedish	O
Telecom	O
company	O
's	O
network	O
had	O
the	O
name	O
SESAM	B-Application
and	O
came	O
in	O
operation	O
in	O
the	O
early	O
1980s	O
.	O
</s>
<s>
The	O
big	O
break	O
for	O
reference	B-Device
computer	I-Device
,	O
which	O
is	O
a	O
Swedish	O
invention	O
,	O
came	O
when	O
the	O
telephone	O
service	O
's	O
large	O
"	O
electronic	O
PBX	O
"	O
A345	O
and	O
A335	O
were	O
provided	O
with	O
a	O
reference	B-Device
computer	I-Device
(	O
HVD	O
)	O
.	O
</s>
<s>
SESAM	B-Application
system	O
was	O
first	O
developed	O
and	O
marketed	O
,	O
then	O
from	O
the	O
mid-1980s	O
,	O
known	O
as	O
PRESENT	O
.	O
</s>
<s>
Reference	B-Device
computers	I-Device
and	O
direct	O
function	O
in	O
the	O
newer	O
PBX	O
contributed	O
to	O
the	O
rationalization	O
of	O
the	O
telecom	O
network	O
.	O
</s>
