Apple BASIC

Apple I - BASIC manual 2 Apple I - BASIC manual 1

Apple 1 basic was on cassette tape and took about 30 seconds to load.

Some of the following was in the BASIC:

  • variables, numeric simple variable, A,N, A1, T6
  • Numeric array variable, N, T, B1, T4
  • character string variable, letter+$, A$,N$

Functions

  • ABS(X), SGN(x), Peek(x), Rnd(x), Len(var$).
  • Arrays, A(15), D(100). Used the Dim statement ot declare.
  • Strings= Print "this is a string", used the quotes.
  • Substrings, A$="ABCDEFG"
  • Print A$ = ABCDEFG
  • Print A$(5) = EFG
  • Print A$(2,6)= BCDEF

Commands

  • Auto val1, val2==== Starts automatically supplying line numbers.
  • val1= first line number value.
  • Val2= increment between line numbers valuse.
  • Clr== sets all variables to zero.
  • Del val1, val2, erases from the program all lines numbered from val1 to val2. if just val1 is used, one line is deleted.
  • List val1,val2, displays all program statements on lines numbered from val1to val2. If you use just list the whole program is listed.
  • RUN val1 - does a CLR then initiates program execution beginning at line val1. if val1 is omitted, program starts at lowest number.
  • SCR == Deletes the entire program, nothing is saved.
  • HIMEM =(expr) sets the high memory boundary for user programs, in decimal. Initializes to 4096.
  • LOMEM=(expr) sets the low memory boundary for user programs,in deciaml. Initializes to 2048.

Statements:

  • LET
  • INPUT
  • PRINT
  • TAB(EXPR)
  • FOR
  • NEXT
  • IF(EXPR) THEN
  • GOTO
  • GOSUB,
  • RETURN
  • DIM
  • REM
  • END
  • POKE EXPR1
  • EXPR2
  • CALL

In Apple Basic you could input more than one statement on a line. Each statement must be separated by a colon (Smile.

Error messages

  • SYNTAX
  • >32767 ERR
  • >255 ERR, A VALUE RESTRICTED TO THE RANGE 0 TO 255 WAS OUTSIDE THAT RANGE.
  • BAD BRANCH ERR
  • BAD RETURN ERR
  • BAD NEXT ERR
  • >8 GOSUBS ERR Results from more than 8 nested GOSUBS.
  • >8 FORS ERR Results from more than 8 nested FOR loops.
  • END ERR Last statement was not an END.
  • MEM FULL ERR
  • TOO LONG ERR Results from too many nested parentheses.
  • DIM ERR
  • RANGE ERR An array or string subscript was larger than the Dimensioned value or smaller that 1.
  • STR OVFL ERR The number of characters assigned to a string exceeded the dimensioned value for that string.
  • STRING ERR Results from an attempt to execute an illegal string operation.
  • RETYPE LINE Results from illegal data being typed in response to an INPUT statement.

Apple I - BASIC cassette