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Apple II Programmer's Reference

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Apple II Programmer's Reference

Here's a brief list of Applesoft, Integer Basic, DOS 3.3, and ProDOS commands with descriptions.

I found these in the back of a manual for II in a Mac, one of the first Apple II emulators that ran on the original Mac and Mac 512. It came out in 1985.

Statements and Lines  
A line typed without a line number is executed immediately; those lines typed with a line number are saved for execution with the RUN command.
: Separates multiple statements on the same line.
REM Designates a remark for comments.
Operations on Whole Programs
NEW Erases the current program and clears all variables.
CLEAR Resets all variables.
LIST Displays the entire current program.
LIST 11-12 Displays the lines from 11 to 12.
RUN Executes the current program.
RUN n Executes the current program from line n.
RUN name Executes the program name from disk.
LOAD name Loads the program name from disk.
SAVE name Saves the program on the disk as name.
Integer AB +/- 32767
String AB$ 0 to 255 characters
Where A is a letter, B is a letter or digit.
DIM Allocates space for an array or string.
Arithmetic Operators  
= Assigns a value to a variable
- Subtraction
+ Addition
/ Division
* Multiplication
^ Exponentiation
Logical Operators  
AND Both true
OR Either one or both true
NOT Is false
Relational Operators  
= Equal to
< Less than
> Greater than
<= Less than or equal to
>= Greater than or equal to
# Not equal to
Arithmetic Functions  
ABS(x) Absolute value of x
SGN(x) -1 if x<0, 0 if x=0, 1 if x>0
RDN(x) Random number in the range 0 <= r < x
String Operations  
LEN(s) Length of string s
ASC(s) ASCII code for first character in string s
GOTO n Branches to line n
IF cond THEN s1 Executes statement if expr is true
FOR v=x TO y STEP z Begins a loop for all values of v from x to y by z; if step is omitted, 1 is understood.
NEXT v Repeats loop for next value of v
GOSUB n Branches to subroutine at line n
RETURN Returns to point of call from a subroutine
POP Removes one address from the return stack
STOP Halts program and print line number
CON Resumes program execution
END Halts program execution
Utility Statements  
PEEK(addr) Value of memory location addr
POKE addr,x Sets memory location addr to x
CALL addr Executes machine language routine at addr
HIMEM:addr Sets highest available memory to addr
LOMEM:addr Sets lowest available memory to addr.
TRACE Displays the number of each executed line
NOTRACE Turns line numbering off
DSP v1,v2.. Displays v1,v2...each time they change.
GR Sets lores graphics mode and clears screen
COLOR=x Sets lores drawing color to x
PLOT x,y Draws a dot at location x,y
HLIN x1,x2 at y Draws a horizontal line from x1,y to x2,y
VLIN y1,y2 at x Draws a vertical line from x,y1 to x,y2
SCRN(x,y) The color of the dot at location x,y.
IN# n Re-directs input from slot n
INPUT s;x,y Prompts with string s, then reads x,y.
PDL(n) Value of paddle n, either 0 or 1
PR# n Re-directs output to slot n
PRINT x,y,... Prints strings or values
TEXT Sets text mode
VTAB n Sets vertical position to n
Links to other command sets: Applesoft | DOS 3.3 | ProDOS
July 7, 2009