VISUAL
TECHNOLOGY
INCORPORATED,
540
MAIN
STREET,
TEWKSBURY,
MA
01876
If
multiple
numeric
or
selective parameters are
used
in a
control
sequence,
they
must
be
separatedwith a semi-colon character.
Some
of
the
control
sequences described in this section
are
not
specified in the ANSI
X3.64
standard,
but
have been added
to
enhance the operational capabilities
of
the
VISUAL
100
when in ANSI mode. The
control
sequences
that
are
not
actually specified in the
X3.64
standard are noted
as
private
control
sequences.
5.3.2.2 Scrolling Region Command,
ESC
[x;y
r(Private)
This command
is
used
to
set
the
top
and
bottom
lines
of
the screen scrolling region. The
lines
on
the screen are numbered 1-24. The
first
numeric parameter,
x,
sets
the
top
boundary, and
the
second numeric parameter,
y,
sets
the
bottom
boundary
of
the scrolling
region. (Both numeric parameters are in decimal
notation.)
The
default
values are the
entire screen, i.e., x=1 and y=24. The
minimum
size
of
the
scrolling region
is
two
lines.
Once the scrolling region
is
defined the cursor positioning commands may move the cursor
into
but
not
out
of
the
scrolling region.
5.3.2.3 Cursor Positioning Commands
The cursor positioning commands described in this section may
cause
a varying action
depending on
two
factors: The defined scrolling region and the current state
of
Origin
mode.
The user may define the scrolling region
of
the screen
as
described in Section 5.3.2.2.
Once the scrolling region
is
defined, incremental cursor positioning commands (Up, Down,
Right, Left) can position
the
cursor anywhere
within
the scrolling region,
but
cannot
position
the
cursor outside
of
the scrolling region. The Absolute Cursor Positioning com-
mand remains unaffected
by
the screen scrolling region.
After
the screen scrolling region
is
defined, a choice
is
provided
for
having line and column
numbers on the screen dependent
or
independent
of
the defined scrolling region.
For
example,
if
line and column numbers are independent
of
the
defined scrolling region,
an
received Absolute Cursor Positioning command
with
line and
column
parameters
of
1,
would
position the cursor
to
the upper left-hand corner
of
the screen.
If
line and column
numbers
are
dependent on
the
defined scrolling region,
the
aforementioned command
would
position the cursor
to
the upper left-hand corner
of
the scrolling region.
Simply
stated, the
current
state
of
Origin mode affects
only
the numbering
of
lines and columns
on
the
screen and thus
only
the Absolute Cursor Positioning command.
Cursor Up, Down, Right,
Left,
ESC [
Pn
F
By
using a single
control
sequence the cursor may
be
moved any number
of
increments up,
down,
right
or
left. The numeric parameter specifies
how
many increments the cursor
is
to
move (default value
is
one) and the value
of
the
termination
character, F, determines the
direction
of
movement
as
specified in Table 5-4.
33
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