Apple II User Manual

POKE            POKE location, byte                                     357 POKE I,J

                The POKE statement stores the byte

                specified by its second argument (J) into

                the location given by its first argument (I).

                The byte to be stored must be =>0 and

                <=255, or an FC error will occur.  The

                address (I) must be =>0 and <=65535, or

                an FC error result.  Caution:  Careless use

                of the POKE statement may cause your

                program, BASIC, or the Monitor functions

                to operate incorrectly, to hang up, and/or

                cause loss of your program.  Note that

                Pages 0 and 1 in memory are reserved for

                use by BASIC and should not be used for

                user program variable storage.  A POKE to

                a non-existent memory location is harmless.

                One of the main uses of POKE is to pass

                arguments to machine language subroutines.

                (See Appendix F.)  You could also use

                PEEK and POKE to write a memory

                diagnostic or an assembler in BASIC.

STATEMENT       SYNTAX/FUNCTION                                         EXAMPLE

RUN             RUN line number                                         RUN 200

                Starts execution of the program currently in

                memory at the specified line number.  RUN

                deletes all variables [does a CLEAR) and

                restores DATA.  If you have stopped your

                program and wish to continue execution at

                some point in the program, use a direct

                GOTO statement to start execution of your

                program at the desired line, or CONT to

                continue after a break.

                Start program execution at the lowest                   RUN

                numbered statement.

STATEMENT       SYNTAX/FUNCTION                                         EXAMPLE

SAVE            SAVE                                                    SAVE

                Saves the current program in the AIM 65

                memory on cassette tape.  The program in

                memory is left unchanged.  More than one

                program may be stored on cassette using

                this command.

                See Appendix G for more information.

304  PROGRAM STATEMENTS

In the following description of statements, an argument of B, C, V or W denotes a numeric variable,

X denotes a numeric expression, X$ denotes a string expression and an I or J denotes an expression

that is truncated to an integer before the statement is executed.  Truncation means that any

fractional part of the number is lost, e.g., 3.9 becomes 3, 4.01 becomes 4.

An expression is a series of variables, operators, function calls and constants which after the

operations and function calls are performed using the precedence rules, evaluates to a numeric

or string value.

A constant is either a number (3.14) or a string literal ("FOO").

STATEMENT       SYNTAX/FUNCTION                                         EXAMPLE

DEF             DEF FNx [(argument list)] = expression                  100 DEF FNA(V)=V/B+C

                The user can define functions like the built-

                in functions (SQR, SGN, ABS, etc.) through

                the use of the DEF statement.  The name

                of the function is "FN" followed by any

                legal variable name, for example:  FNX,