Error Codes

When an error happens, you can use the ERROR operation to figure out what went wrong. ERROR outputs a list whose items describe the error. The first item is a numeric code for the type of error that occurred. The second item is a human-readable message that explains the error.

Some messages may have two different codes depending on whether the error is recoverable (that is, if a substitute value can be provided through the ERRACT mechanism).

Some messages are warnings rather than errors; these can not be caught.

The conditions which generate the first two error codes so bad that Logo exits immediately. These also cannot be caught.

The numeric error codes and their corresponding human-readable messages are given in the table below.

Error CodeError Message
0Fatal internal error (can't be caught)
1Out of memory (can't be caught)
2Stack Overflow
3Turtle out of bounds
4PROC doesn't like DATUM as input (not recoverable)
5PROC didn't output to PROC
6Not enough inputs to PROC
7PROC doesn't like DATUM as input (recoverable)
8Too much inside ( )'s
9I don't know what to do with DATUM
10')' not found
11VAR has no value
12Unexpected ')'
13I don't know how to PROC (recoverable)
14Can't find catch tag for THROWTAG
15PROC is already defined
17Already dribbling
18File system error
19Assuming you mean IFELSE, not IF (warning only)
20VAR shadowed by local in procedure call (warning only)
21User-initiated THROW "Error
22PROC is a primitive
23Can't use TO inside a procedure
24I don't know how to PROC (not recoverable)
26Unexpected ']'
27Unexpected '}'
28Couldn't initialize graphics
29Macro returned VALUE instead of a list
30I don't know what to do with VALUE
31Can only use STOP or OUTPUT inside a procedure
32APPLY doesn't like DATUM as input.
33END inside multi-line instruction
1001WINDOW already exists
1002WINDOW does not exist
1101DLL load failed
1102DLL is not loaded
1103Not all Type/Data inputs are paired
1104Invalid data type input
1105Invalid output type
1106Function not found
1201Problem Reading GIF, check memory and diskspace
1202Problem Generating GIF, check memory and diskspace
1211Could not open .bmp
1212Unable to create Windows 3.0 bitmap
1213Could not write .bmp
1214Not a Windows 3.0 bitmap
1300MIDI Error
1301MIDI Error: Already open
1302MIDI Error: Invalid MIDI device
1303MIDI Error: Not open
1401Timer not found
1500Invalid state for instruction
2001PROC cannot be run on PROC because it has a special form Logo