This page is a list of Commodore 64 errors and their likely causes:
DEVICE NOT PRESENT
DIVISION BY ZERO
You somehow tried to divide by zero. This isn't even possible in advanced math.
10 REM THIS IS BAD 20 PRINT 20 / 0 30 END
If you are not sure where you attempted to divide by zero, one of the divisors could be a variable that somehow is set to zero.
10 REM THE VARIABLE IS 0 20 A = 0 30 PRINT 20 / A 40 END
FILE NOT FOUND
FILE NOT OPEN
FORMULA TOO COMPLEX
NEXT WITHOUT FOR
10 FOR I = 1 to 20 20 PRINT I 30 REM THERE IS NO NEXT TO RETURN THE 40 REM FOR LOOP TO LINE 10
You typed in something incorrectly as a misspelling. Also, you could have attempted to type in something that doesn't make sense in Commodore BASIC.
UNDEF'D STATEMENT ERROR IN (line number)
10 GOTO 40 20 REM SINCE THERE IS NO LINE 40 30 REM THE GOTO HAS NO PLACE TO GO
This will definitely cause an error. However, its worthy to note that you can send a GOTO to a line with an REM statement in it, even though it technically does nothing.
10 GOTO 20 20 REM USELESS BUT LEGAL REM 30 END