This table gives each report code with a general description & a list of the situations where it can occur. In appendix C, a more detailed description of what error reports mean is given under each statement or function.
| Code | Meaning | Situations |
| 0 | Successful completion, or jump to line number bigger than any existing. A report with code 0 does not change the line number used by CONT. | Any |
| 1 | The control variable does not exist (has not been set up by a FOR statement) but there is an ordinary variable with the same name. | NEXT |
| 2 | An
undefined variable has been used. For a simple variable this will happen if the variable is used before it has been assigned to in a LET statement. For a subscripted variable it will happen if the variable is used before it has been dimensioned in a DIM statement. For a control variable this will happen if the variable is used before it has been set up as a control variable in a FOR statement, when there is no ordinary simple variable with the same name. |
Any |
| 3 | Subscript
out of range. If the subscript is hopelessly out of range (negative, or bigger than 65535) then error B will result. |
Subscripted variables |
| 4 | Not enough room in memory. Note that the line number in the report (after the /) may be incomplete on the screen, because of the shortage of memory: for instance 4/20 may appear as 4/2. See chapter 23. For GOSUB see exercise 6 of chapter 14. | LET, INPUT, DIM, PRINT, LIST, PLOT, UNPLOT, FOR, GOSUB. Sometimes during function evaluation. |
| 5 | No more room on the screen. CONT will make room by clearing the screen. | PRINT, LIST. |
| 6 | Arithmetic overflow: calculations have led to a number greater than about 1038. | Any arithmetic |
| 7 | No corresponding GOSUB for a RETURN statement. | RETURN |
| 8 | You have attempted INPUT as a command (not allowed). | INPUT |
| 9 | STOP statement executed. CONT will not try to re-execute the STOP statement. | STOP |
| A | Invalid argument to certain functions. | SQR, LN, ASN, ACS |
| B | Integer out
of range. When an integer is required, the floating point
argument is rounded to the nearest integer. If this is
outside a suitable range then error B results. For array access, see also report 3. |
RUN,
RAND, POKE, DIM, GOTO, GOSUB,
LIST, LLIST, PAUSE, PLOT, UNPLOT,
CHR$, PEEK, USR Array access |
| C | The text of the (string) argument of VAL does not form a valid numerical expression. | VAL |
| D | (i) Program
interrupted by BREAK. (ii) The INPUT line starts with STOP. |
At end of
any statement, or in LOAD, SAVE, LPRINT,
LLIST or COPY. INPUT |
| E | Not used | |
| F | The program name provided is the empty string. | SAVE |