<s>
The	O
first	O
character	O
of	O
each	O
line	O
of	O
text	O
is	O
interpreted	O
as	O
a	O
control	O
character	O
or	O
printer	O
command	O
instead	O
of	O
a	O
character	O
to	O
be	O
printed	O
if	O
a	O
corresponding	O
attribute	O
is	O
set	O
for	O
the	O
print	O
data	B-Application
set	I-Application
(	O
data	B-Application
set	I-Application
is	O
mainframe	O
speak	O
for	O
what	O
is	O
known	O
as	O
a	O
file	O
on	O
other	O
operating	O
systems	O
)	O
.	O
</s>
<s>
This	O
tape	O
is	O
called	O
a	O
carriage	B-Device
control	I-Device
tape	I-Device
and	O
is	O
mounted	O
on	O
the	O
printer	O
.	O
</s>
<s>
The	O
looped	O
carriage	B-Device
tape	I-Device
moves	O
synchronously	O
with	O
the	O
stream	O
of	O
fanfold	O
paper	O
.	O
</s>
<s>
The	O
line	O
printers	O
have	O
12	O
sensors	O
to	O
recognize	O
12	O
independent	O
positions	O
on	O
the	O
carriage	B-Device
control	I-Device
tape	I-Device
.	O
</s>
<s>
For	O
example	O
,	O
if	O
the	O
first	O
line	O
of	O
text	O
has	O
to	O
always	O
be	O
on	O
physical	O
line	O
3	O
for	O
a	O
given	O
form	O
,	O
then	O
the	O
channel	O
1	O
hole	O
has	O
to	O
be	O
punched	O
in	O
line	O
3	O
of	O
the	O
carriage	B-Device
control	I-Device
tape	I-Device
.	O
</s>
<s>
Print	O
data	B-Application
sets	I-Application
on	O
IBM	O
mainframe	O
operating	O
systems	O
may	O
have	O
either	O
of	O
two	O
variants	O
of	O
printer	O
control	O
characters	O
:	O
</s>
<s>
RECFM	O
=	O
A	O
..	O
specifies	O
that	O
the	O
data	B-Application
set	I-Application
contains	O
ASA	O
control	O
characters	O
.	O
</s>
<s>
RECFM	O
=	O
M	O
..	O
specifies	O
that	O
the	O
data	B-Application
set	I-Application
contains	O
IBM	O
machine	O
control	O
characters	O
.	O
</s>
<s>
COBOL	B-Application
and	O
PL/I	B-Language
also	O
have	O
a	O
system-independent	O
method	O
of	O
specifying	O
printer	O
controls	O
.	O
</s>
<s>
COBOL	B-Application
uses	O
the	O
syntax	O
WRITE	O
record-name	O
AFTER	O
ADVANCING	O
n	O
Lines.	O
,	O
where	O
record-name	O
is	O
the	O
name	O
of	O
the	O
area	O
containing	O
the	O
line	O
and	O
n	O
is	O
the	O
number	O
of	O
lines	O
.	O
</s>
<s>
PL/I	B-Language
uses	O
the	O
syntax	O
PUT	O
SKIP(n )	O
...	O
to	O
skip	O
n	O
lines	O
before	O
printing	O
,	O
or	O
PUT	O
PAGE	O
...	O
to	O
skip	O
to	O
a	O
new	O
page	O
.	O
</s>
