Commodore Plus 4 - Setting up your Commodore Plus;4

The Elements of BASIC 7
called Boolean operators. Their role is to check the truth value of two values,
which may be constants, numeric variables, or calculations. A result of 0 is false,
and any other value is considered true.
Numeric values (operands) on either side of a logical operator should be
integer numbers, not floating-point numbers, so that they are between -32767
and 32767. If you use a floating-point number, it is converted to an integer
number. The result of a logical operation is always an integer value.
You can also use the logical operators to AND or OR individual bits (binary
digits) in two operands. You can use NOT to invert individual bits in a single
operand.
The following chart shows how each of the logical operators provides a result
after combining the truth values of two values. A value of -1 is used for a true
result.
-1AND-1 = -1 -1OR-1=-1 NOT-1= 0 -1 XOR -1 = 0
-1 AND 0= 0 -1OR 0 = -l NOT 0 = -1 -1 XOR 0 = -l
0AND-l= 0 0OR-l = -l 0XOR-l=-l
OAND 0=0 0OR 0= 0 0 XOR 0= 0
Logical AND
AND requires both values to be true for the result of the ANDed expression to be
true. Any other combination produces a false result. AND lets you set compound
comparisons in a conditional command such as IF or WHILE. When you join a
compound IF or WHILE command with AND, the result of the compound
comparison is false if one or both of the conditions are false. For example
10 INPUT "AGE, ANNUAL INCOME"; X, Y
20 IF X=>60 AND Y<= 10000 THEN PRINT "ELIGIBLE": ELSE PRINT
"INELIGIBLE"
RUN
AGE, ANNUAL INCOME ? 60,15000
INELIGIBLE
RUN
AGE, ANNUAL INCOME ? 65, 9900
ELIGIBLE
The IF command in the first execution is false because only one IF condition is
true (X is greater than or equal to 60, but Y is not less than or equal to 10000).
Therefore the THEN clause does not execute, and the ELSE clause does execute.
In the second execution of the program, the IF command is true because both the
first AND the second condition are true.