Radio Shack TRS-80 Model III - Page 47

OPERATION
When address 16427
contains a value
of
255,
the
maximum line length
feature is
disabled.
No
matter how
long the line is,
the Computer
will not insert
carriage
returns in it. Remember,
though, some
printers
automatically do this
when the line
exceeds a specified
length.
When you start BASIC,
address
16427
contains a value of
255,
so the
maximum line
length function is
disabled.
Page
Controls
In
many printer applications
,
you want to
control the
number of lines that
are
printed on a page . For
example , in
printing forms or
reports
,
when a
given number
of
lines have been printed
,
you
want to
advance the
paper to the top
of the next
page.
Model III BASIC has
several features to
help you do
this
.
It keeps
track of the
following
information:
Data
Memory Address
Page
size: number of
lines per
16424
page
plus one. Initialized
to67
=
66+ 1.
Line count:
number of lines
16425
(carriage returns)
already
printed plus one
.
Initialized to one.
Most printers output
six lines per inch;
therefore standard 1
1
"
paper allows 66 lines,
which matches BASIC'S
initialization value.
To change
the maximum
lines/page setting,
store the desired
number of lines plus
one in 1 6424 .
For example , if your
paper contains 88
lines per page
,
then execute this
BASIC statement:
POKE
16424, 89
When you
start the Computer,
position the paper to
the
top
of the page ("top
of
form"). That
way BASIC'S initial page
information
is correct. Each time
BASIC
outputs a line (i.e.
, a carriage return), the
line count is
incremented.
Note:
If your printer's
maximum line-length
is shorter than
BASIC'S maximum line
length, the printer will insert
carriage returns
that BASIC isn't
allowing for.
Therefore BASIC'S line count
will not
be
accurate.
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