ATN

Action: This mathematical function returns the arctangent of the number. The result is the angle (in radians) whose tangent is the number given. The result is always in the range -π/2 to +π/2.

   10 PRINT ATN(0)
   20 X = ATN(J)*180/π : REM CONVERT TO DEGREES

CHR$

Action: This function converts a Commodore ASCII code to its character equivalent. See Appendix C for a list of characters and their codes. The number must have a value between 0 and 255, or an ?ILLEGAL QUANTITY error message results.

   10 PRINT CHR$(65) : REM 65 = UPPER CASE A
   20 A$=CHR$(13) : REM 13 = RETURN KEY
   50 A=ASC(A$) : A$ = CHR$(A) : REM CONVERTS TO C64 ASCII CODE AND BACK