Commodore 16 User Manual
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VOL
VOL volume level
Seis
Ibe current
VOLume level
(or
SOUND
commands.
VOLume may
be set from
to 8,
where
8
is maximum volume,
and
is off.
VOL
aff
eels both voices
WAIT
WAIT address, value 1
(.
value
2]
The WAIT statement
is used to halt the
program until
the contents ol a
location in memory changes in
a
specific
way
The address must
be
In
the
range from
to 65535
Value
1 and value 2 must be in the range
from
to 255.
The content of the memory location is first exclusive-ORed with value 2
(if present), and Ihen logically ANDed with value 1 It the result is zero,
the program checks the memory location again When the result is not
zero, the program continues
with
the next statement.
Additional Graphic Statement Information
There
are a
few
concepts that apply to ail ol the
bit
map
graphics
statements First is the concept
of the
Pixel Cursor (PC). The PC Is
similar to the cursor in text mode; it is the position where the next dot
is
to be drawn. Unlike the text cursor, the PC is invisible. All drawing
commands use Ihe PC
In addition,
the locate command
allows
you to
reposition Ihe PC without drawing anything
Wherever you would use X, V coordinates in a drawing command, you
can use RELATIVE coordinates instead. Relative coordinates are based
on the current value of the
PC To use
relative coordinates,
just place a
+
or -
in
front
of your coordinates. A plus sign before the X value
moves the
PC to Ihe right A minus sign before the X value moves the
PC
to
the
left.
Similarly,
a
minus
sign
before
Ihe
Y
coordinate moves
the PC
up,
while
a plus
sign moves
the
PC down. For example:
142
I
I
f
(
(
I
(
f
I
!
f
LOCATE
+100,-23
moves
the PC right 1 00 pixels and up
25
DRAWl
,
+ 10, + 10TO100, 100
draws
a
line
1
pixels right and 1
pixels below Ihe current value of Ihe
PC to the absolute
point 100.100
You
can
also
specify a
distance and and angle relative
to
the current
PC
by
separating the two parameters by a
semicolon
For example:
LOCATE 50;45
moves the PC
from its current location
by
a
distance of 50 dots at
an
angle
of
45 degrees.
FUNCTIONS
Numeric Functions
Numeric functions are classified as such because Ihey return
numbers.
The
functions
they perform range
from calculating matnematical
functions
lo
specifying
a
screen location Numeric functions follow the
form.
FUNCTION
(argument)
where the argument
can be a
numerical value, variable, or string
ABS(X) (absolute value)
The absolute value function
returns
the magnitude
of
the
argument
X.
ASC(X$>
This function returns
the ASCII code
(number) of the first character of
X$.
I
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