Atari BASIC Reference
Guide
157
EXAMPLE
10 GRAPHICS 3
20
COLOR
2
30 FOR I = 0
TO
35
STEP
5
40 PLOT 1,0
50
NEXT
I
The
previous
example
contains a
program
that
uses
a PLOT
statement. Line 10 indicates graphics
mode
3. Line 20 chooses
the
color
register
2.
Since
no
SETCOLOR
statement
was
executed,
color
register 2 defaults
to
green. Line 30 begins a FORI NEXT
loop
that
is
exec
uted
8
tim
e
s.
The value
of
the
counter
(I)
is
set
to
equal 0, 5, 10, 15 ... 35.
As
a resuic
line
40 causes
green
picture
elements
to
appear
evenly
spaced across
the
top
of
the
display.
The
PLOT statement indicates positions
(O,OL
(5,OL
(10,
0)
... (35,
0)
.
The fi rst
argument
is
the
col u mn, and
the
se
cond
argu me
nt
is
the
row. The second value indicates
the
top
line
(zero
row)
of
the
display.
POINT
(P.)
The POI NT statement
is
used
only
in disk
operations
to
move
the
file
pointer
to
a given
location
.
CONFIGURATION
POI NT
#a
, b, c
The first
argument
of
a
POINT
stateme
nt
indicates an
1/0
channel. The cha
nnel
mu
st be
open
to
a disk
for
inpuc
update,
or
append
. The second arg
ument
is
the
sector value. The sector
value must lie
within
the
limits
of
the
fil
e.
The
third
argument
is
the
number
of
the
byte
within
the sector. The
third
argument
must
be
between
0 and 125. If any
of
the
arguments
are
not
integers,
they
are
round
ed
off.
The
POINT
command
is
not
valid in
version
1.0
of
the
disk
operating
system.
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