Commodore PET - CHAPTER 5: Making the Most of PET Features; KEYBOARD ROLLOVER

Prints -1.
Prints O.
Prints 1.
You can compare these operations to a deck of cards: RND(- Til is like shuf-
fling the deck.
RND(O) is like cutting the cards. and RND(-RND(O)) is like giving
the cards both a shuffle and a eut.
To generate random numbers in non-repeating sequences
as would be
needed. say. in games of chance. use RND(-RND(O)) to store a random seed and
then fetch
as many random numbers as needed with RND (1) references. where 1
can
be 1 or any other positive. non-zero number.
Examples of using the
RND function to generate random numbers on the
PET are given in Chapter 5.
SGN
SGN. for sign of a number. can be used to determine if a number is positive.
negative. or
zero.
Format:
SGN(arg)
where:
arg
is a numeric constant. variable. or
expression.
The
SGN function returns: +1 if the number is positive.
non-zero.
oif the nu mber is zero.
-1 if the number is negative.
Examples:
?SGN(-6)
?SGN(O)
?SGN(44)
IF A>C THEN SA=SGN(X)
IF SGN(M) > =0 THEN PRINT "POSITIVE NUMBER"
SIN
SIN returns the sine of the argument.
Format:
SIN(arg)
where:
arg
Examples:
A=SIN(AG)
?SIN (45*1T/180)
154
is a numeric constant. variable. or expression
representing an angle
in radians.
Prints sine of 45 degrees.