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 
 | DESCRIPTION | 
| 1
 | TOO MANY FILES 
 | There is a limit of 10 files OPEN at one time. | 
| 2
 | FILE OPEN 
 | An attempt was made to open a file using the number of an already open file. | 
| 3
 | FILE NOT OPEN 
 | The file number specified in an I/O statement must be opened before use. | 
| 4
 | FILE NOT FOUND 
 | Either no file with that name exists (disk) or an end-of-tape marker was read (tape). | 
| 5
 | DEVICE NOT PRESENT 
 | The required I/O device is not available or buffers deallocated (cassette). Check to make sure the device is connected and turned on.
 | 
| 6
 | NOT INPUT FILE 
 | An attempt was made to GET or INPUT data from a file that was specified as output only. | 
| 7
 | NOT OUTPUT FILE 
 | An attempt was made to send data to a file that was specified as input only. | 
| 8
 | MISSING FILE NAME 
 | File name missing in command. | 
| 9
 | ILLEGAL DEVICE NUMBER 
 | An attempt was made to use a device improperly (SAVE to the screen, etc.). | 
| 10
 | NEXT WITHOUT FOR 
 | Either loops are nested incorrectly, or there is a variable name in a NEXT statement that doesn't correspond with one in FOR. | 
| 11
 | SYNTAX 
 | A statement not recognized by BASIC. This could be because of a missing or extra parenthesis, misspelled key word, etc. | 
| 12
 | RETURN WITHOUT GOSUB 
 | A RETURN statement was encountered when no GOSUB statement was active. | 
| 13
 | OUT OF DATA 
 | A READ statement was encountered without data left unREAD. | 
| 14
 | ILLEGAL QUANTITY 
 | A number used as the argument of a function or statement is outside the allowable range. | 
| 15
 | OVERFLOW 
 | The result of a computation is larger than the largest number allowed (1.701411833E+38). | 
| 16
 | OUT OF MEMORY 
 | Either there is no more room for program code and/or program variables, or there are too many nested DO, FOR or GOSUB statements in effect. | 
| 17
 | UNDEF'D STATEMENT 
 | A line number referenced doesn't exist in the program. | 
| 18
 | BAD SUBSCRIPT 
 | The program tried to reference an element of an array out of the range specified by the DIM statement. | 
| 19
 | REDIM'D ARRAY 
 | An array can only be DIMensioned once. | 
| 20
 | DIVISION BY ZERO 
 | Division by zero is not allowed. | 
| 21
 | ILLEGAL DIRECT 
 | INPUT or GET, or INPUT# or GET# statements are only allowed within a program. | 
| 22
 | TYPE MISMATCH 
 | This occurs when a numeric value is used in place of a string or vice versa. | 
| 23
 | STRING TOO LONG 
 | A string can contain up to 255 characters. | 
| 24
 | FILE DATA 
 | Bad data read from a tape or disk file. | 
| 25
 | FORMULA TOO COMPLEX 
 | The computer was unable to understand this expression. Simplify the expression (break into two parts or use fewer parentheses). | 
| 26
 | CAN'T CONTINUE 
 | The CONT command does not work if the program was not RUN, there was an error, or a line had been edited. | 
| 27
 | UNDEFINED FUNCTION 
 | A user-defined function was referenced that was never defined. | 
| 28
 | VERIFY 
 | The program on tape or disk does not match the program in memory. | 
| 29
 | LOAD 
 | There was a problem loading. Try again. | 
| 30
 | BREAK 
 | The stop key was hit to halt program execution. | 
| 31
 | CAN'T RESUME 
 | A RESUME statement was encountered without a TRAP statement in effect. | 
| 32
 | LOOP NOT FOUND 
 | The program has encountered a DO statement and cannot find the corresponding LOOP. | 
| 33
 | LOOP WITHOUT DO 
 | LOOP was encountered without a DO statement active. | 
| 34
 | DIRECT MODE ONLY 
 | This command is allowed only in direct mode, not from a program. | 
| 35
 | NO GRAPHICS AREA 
 | A command (DRAW, BOX, etc.) to create graphics was encountered before the GRAPHIC command was executed. | 
| 36
 | BAD DISK 
 | An attempt failed to HEADER a diskette, because the quick header method (no ID) was attempted on a unformatted diskette or the diskette is bad. | 
| 37
 | BEND NOT FOUND 
 | The program encountered an "IF... THEN BEGIN" or "IF... THEN... ELSE BEGIN" construct, and could not find a BEND keyword to match the BEGIN. | 
| 38
 | LINE # TOO LARGE 
 | An error has occurred in renumbering a BASIC program. The given parameters result in a line number > 63999 being generated; therefore, the renumbering was not performed. | 
| 39
 | UNRESOLVED REFERENCE 
 | An error has occurred in renumbering a BASIC program. A line number referred to by a command (e.g., GOTO 999) does not exist. Therefore the renumbering was not performed. | 
| 40
 | UNIMPLEMENTED COMMAND 
 | A command not supported by BASIC 7.0 was encountered. | 
| 41
 | FILE READ 
 | An error condition was encountered while loading or reading a program or file from the disk drive (e.g., opening the disk drive door while a program was loading). |