Commodore 128 System Manual page 365

APPENDIX A
BASlC LANGUAGE ERROR
MESSAGES
The following error messages are displayed by BASIC. Error
messages can also be displayed with the use of the ERR$()
function. The error numbers below refer only to the number
assigned to the error for use with the ERR$() function.
ERROR# ERROR NAME
1 TOO MANY FILES
2 FILE OPEN
3 FILE NOT OPEN
4 FILE NOT FOUND
5 DEVICE NOT PRESENT The required I/O device is
6 NOT INPUT FILE
DESCRIPTION
There is a limit of 10
files OPEN at one time.
An attempt was made to
open a file using the
number of an already
open file.
The file number
specified in an I/O
statement must be
opened before use.
Either no file with that
name exists (disk) or
an end-of-tape marker
was read (tape).
not available or buffers
deallocated (cassette).
Check to make sure device
is connected and turned on.
An attempt was made to GET
or INPUT data from a
file that was specified
as output only.
A-1