Sinclair ZX81 - Report Codes

Appendix B - Report codes
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 10
38
.
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