<s>
BESYS	B-Operating_System
(	O
Bell	O
Operating	O
System	O
)	O
was	O
an	O
early	O
computing	O
environment	O
originally	O
implemented	O
as	O
a	O
batch	B-General_Concept
processing	I-General_Concept
operating	O
system	O
in	O
1957	O
at	O
Bell	O
Labs	O
for	O
the	O
IBM	B-Device
704	I-Device
computer	O
.	O
</s>
<s>
According	O
to	O
Drummond	O
,	O
the	O
name	O
BESYS	B-Operating_System
,	O
though	O
commonly	O
thought	O
to	O
stand	O
for	O
BEll	O
SYStem	O
,	O
is	O
actually	O
a	O
concatenation	O
of	O
the	O
preexisting	O
SHARE-assigned	O
installation	O
code	O
BE	O
for	O
Bell	O
Telephone	O
Laboratories	O
,	O
Murray	O
Hill	O
,	O
NJ	O
and	O
the	O
code	O
assigned	O
by	O
SHARE	O
for	O
systems	O
software	O
,	O
SYS	O
.	O
</s>
<s>
Efficient	O
batch	B-General_Concept
processing	I-General_Concept
,	O
tape-to-tape	O
operation	O
with	O
offline	O
spooling	O
of	O
unit-record	O
data	O
.	O
</s>
<s>
Use	O
of	O
control	B-General_Concept
cards	I-General_Concept
to	O
minimize	O
the	O
need	O
for	O
operator	O
intervention	O
.	O
</s>
<s>
Allow	O
user	O
programs	O
access	O
to	O
input/output	B-General_Concept
functions	O
,	O
system	O
control	O
and	O
program	B-Library
libraries	I-Library
.	O
</s>
<s>
Core	B-Error_Name
dump	I-Error_Name
facilities	O
for	O
debugging	O
.	O
</s>
<s>
Simulation	O
of	O
L1	B-Language
and	I-Language
L2	I-Language
interpreters	O
to	O
provide	O
software	O
compatibility	O
with	O
the	O
IBM	B-Device
650	I-Device
.	O
</s>
<s>
The	O
initial	O
version	O
of	O
the	O
system	O
BESYS-1	O
was	O
in	O
use	O
by	O
October	O
16	O
,	O
1957	O
.	O
</s>
<s>
It	O
was	O
created	O
by	O
George	O
H	O
.	O
Mealy	O
and	O
Gwen	O
Hansen	O
with	O
Wanda	O
Lee	O
Mammel	O
and	O
utilized	O
IBM	O
's	O
FORTRAN	B-Application
and	O
United	O
Aircraft	O
's	O
Symbolic	B-Language
Assembly	I-Language
Program	I-Language
(	O
SAP	O
)	O
programming	O
languages	O
.	O
</s>
<s>
It	O
was	O
designed	O
to	O
efficiently	O
deal	O
with	O
a	O
large	O
number	O
of	O
jobs	O
originating	O
on	O
punched	B-Architecture
cards	I-Architecture
and	O
producing	O
results	O
suitable	O
for	O
printing	O
on	O
paper	O
and	O
punched	B-Architecture
cards	I-Architecture
.	O
</s>
<s>
The	O
system	O
also	O
provided	O
processing	O
capabilities	O
for	O
data	O
stored	O
on	O
magnetic	O
tapes	O
and	O
magnetic	B-Architecture
disk	I-Architecture
storage	O
units	O
.	O
</s>
<s>
Typically	O
punched	B-Architecture
card	I-Architecture
and	O
print	O
processing	O
was	O
handled	O
off	O
line	O
by	O
peripheral	O
Electronic	O
Accounting	O
Machines	O
,	O
IBM	B-Device
1401	I-Device
computers	O
,	O
and	O
eventually	O
direct	O
coupled	O
computers	O
.	O
</s>
<s>
The	O
first	O
system	O
actually	O
used	O
at	O
Bell	O
Labs	O
was	O
BESYS-2	O
.	O
</s>
<s>
The	O
upper	O
4K	O
words	O
held	O
the	O
resident	O
portion	O
of	O
the	O
monitor	O
,	O
and	O
could	O
be	O
partially	O
swapped	O
to	O
magnetic	B-General_Concept
drum	I-General_Concept
to	O
free	O
up	O
additional	O
core	O
for	O
the	O
user	O
program	O
if	O
needed	O
.	O
</s>
<s>
"	O
BESYS	B-Operating_System
was	O
a	O
complex	O
software	O
package	O
that	O
provided	O
convenient	O
input/output	B-General_Concept
and	O
integrated	O
disk	O
file	O
storage	O
facilities.	O
"	O
</s>
<s>
BESYS	B-Operating_System
was	O
used	O
extensively	O
by	O
many	O
departments	O
of	O
Bell	O
Labs	O
for	O
over	O
a	O
decade	O
.	O
</s>
<s>
Versions	O
of	O
the	O
BESYS	B-Operating_System
environment	O
(	O
BESYS-3	O
(	O
1960	O
)	O
,	O
BESYS-4	O
(	O
1962	O
)	O
,	O
BESYS-5	O
(	O
1963	O
)	O
,	O
BESYS-7	O
(	O
1964	O
)	O
,	O
and	O
BE90	O
(	O
1968	O
)	O
)	O
were	O
implemented	O
as	O
the	O
underlying	O
computers	O
transitioned	O
through	O
the	O
IBM	O
709X	O
family	O
.	O
</s>
<s>
BESYS	B-Operating_System
development	O
was	O
discontinued	O
when	O
Bell	O
Labs	O
moved	O
to	O
the	O
IBM	B-Application
System/360	I-Application
in	O
1969	O
.	O
</s>
<s>
Throughout	O
this	O
period	O
the	O
head	O
of	O
the	O
BESYS	B-Operating_System
development	O
project	O
was	O
George	O
L	O
.	O
Baldwin	O
.	O
</s>
