<s>
The	O
IBM	B-Device
2540	I-Device
is	O
a	O
punched-card	B-Architecture
computer	O
peripheral	O
manufactured	O
by	O
IBM	O
Corporation	O
for	O
use	O
of	O
System/360	B-Application
and	O
later	O
computer	O
systems	O
.	O
</s>
<s>
The	O
2540	O
can	O
read	O
punched-cards	B-Architecture
at	O
1000	O
cards	O
per	O
minute	O
(	O
CPM	O
)	O
and	O
punch	B-Device
at	O
300	O
CPM	O
.	O
</s>
<s>
The	O
2540	O
is	O
based	O
on	O
the	O
design	O
of	O
the	O
older	O
,	O
slightly	O
slower	O
,	O
1402	B-Device
.	O
</s>
<s>
The	O
2540	O
attaches	O
to	O
a	O
System/360	B-Application
multiplexer	B-Device
or	I-Device
selector	I-Device
channel	I-Device
through	O
an	O
IBM	B-Device
2821	I-Device
Control	I-Device
Unit	I-Device
.	O
</s>
<s>
A	O
standard	O
2540	O
processes	O
standard	O
IBM	O
80	B-Architecture
column	I-Architecture
punched	B-Architecture
cards	I-Architecture
.	O
</s>
<s>
The	O
card	B-Device
reader	I-Device
(	O
2540R	O
)	O
and	O
card	B-Device
punch	I-Device
(	O
2540P	O
)	O
devices	O
are	O
separately	O
addressable	O
and	O
function	O
independently	O
.	O
</s>
<s>
The	O
2540	O
normally	O
reads	O
and	O
punches	B-Device
EBCDIC	B-Language
data	O
,	O
called	O
data-mode	O
1	O
.	O
</s>
<s>
On	O
the	O
left	O
side	O
of	O
the	O
device	O
is	O
the	O
punch	B-Device
,	O
with	O
an	O
input	O
hopper	O
holding	O
about	O
1350	O
cards	O
,	O
and	O
three	O
output	O
stackers	O
(	O
left	O
to	O
right	O
–	O
P1	O
,	O
P2	O
,	O
and	O
RP3	O
)	O
each	O
holding	O
1350	O
cards	O
.	O
</s>
<s>
The	O
center	O
stacker	O
(	O
RP3	O
)	O
is	O
shared	O
between	O
the	O
reader	O
and	O
the	O
punch	B-Device
,	O
but	O
is	O
not	O
intended	O
to	O
be	O
used	O
by	O
both	O
at	O
the	O
same	O
time	O
.	O
</s>
<s>
Punch-feed-read	O
–	O
this	O
feature	O
allows	O
input	O
cards	O
to	O
be	O
read	O
by	O
the	O
punch	B-Device
unit	O
and	O
data	O
simultaneously	O
punched	O
into	O
the	O
same	O
card	O
.	O
</s>
<s>
This	O
feature	O
was	O
not	O
normally	O
supported	O
by	O
spooling	B-Device
software	O
.	O
</s>
<s>
With	O
the	O
introduction	O
of	O
System/370	B-Device
IBM	O
announced	O
the	O
improved	O
3525	B-Device
card	I-Device
punch	I-Device
and	O
the	O
3505	B-Device
card	I-Device
reader	I-Device
in	O
1971	O
.	O
</s>
