<s>
The	O
IBM	B-Device
2501	I-Device
is	O
a	O
punched-card	B-Architecture
reader	O
from	O
IBM	O
with	O
models	O
for	O
the	O
System/360	B-Application
and	O
System/370	B-Device
mainframe	B-Architecture
systems	O
and	O
for	O
the	O
IBM	B-Device
System/360	I-Device
Model	I-Device
20	I-Device
,	O
the	O
IBM	B-Device
1130	I-Device
and	O
IBM	B-Device
System/3	I-Device
minicomputers	B-Architecture
.	O
</s>
<s>
Models	O
for	O
mainframe	B-Architecture
use	O
come	O
with	O
an	O
integrated	O
control	B-Device
unit	I-Device
that	O
performs	O
the	O
functions	O
of	O
a	O
control	B-Device
unit	I-Device
required	O
by	O
other	O
devices	O
.	O
</s>
<s>
The	O
A1	O
and	O
A2	O
are	O
for	O
the	O
IBM	B-Device
1130	I-Device
.	O
</s>
<s>
In	O
a	O
mainframe	B-Architecture
environment	O
the	O
2501	O
was	O
frequently	O
used	O
for	O
mainframe	B-Architecture
input	O
in	O
an	O
"	O
open	O
shop	O
"	O
environment	O
where	O
users	O
submitted	O
their	O
own	O
jobs	O
.	O
</s>
<s>
On	O
an	O
1130	O
system	O
the	O
2501	O
can	O
be	O
used	O
in	O
addition	O
to	O
the	O
IBM	B-Device
1442	I-Device
.	O
</s>
<s>
The	O
System/3	B-Device
normally	O
processes	O
96-column	O
punched	B-Architecture
card	I-Architecture
;	O
the	O
2501	O
provides	O
alternative	O
input	O
for	O
shops	O
that	O
require	O
the	O
ability	O
to	O
read	O
80-column	O
cards	O
.	O
</s>
