ERROR CODE EXPLANATIONS

The system of programming error detection and reporting
in TARBELL BASIC is a compromise between the need for
clear error reporting, and the memory required for error
detection and messages.  Some systems use error code numbers,
or 1 or 2 code letters.  These usually have to be looked up
in the reference manual, so they waste time.  Some use long
english explanations, which are nice, but take up a lot of
memory space.  TARBELL BASIC uses abbreviated messages, which
are hopefully easy to remember after they're looked up the first
time.

No.  Mnemonic		Description

1    OVRFLW		Arithmetic Overflow (too large a number).
2    UNDRFLW		Arithmetic Underflow (too small a number).
3    /0			A division by zero was attempted.
4    EX>>		Exponent was too large (EXP function).
5    BIN CON >>		Number too large to convert to binary.
6    -LOG		Attempted to take log of a minus number.
7    LINE DES		Illegal line descriptor.
8    COMM		Illegal command.
9    VRBL AS STATE	Variable name used as statement name.
10   SYNTAX		The statement was not properly formed.
11   VRBL NM		Illegal variable name.
12   >>)		Too many right parenthesis.
13   >>(		Too many left parenthesis.
14   2 OPERS		Two operators in a row.
15   2 OPANDS		Two operands in a row.
16   ILGL FUNC		Illegal user defined function.
17   STATE AS VRBL	Statement name used as variable.
18   NEW SYMB		New symbol when in command mode.
19   NO TO		No "TO" in "FOR" statement.
22   CAN'T CONT		Can't continue 'cause program was modified.
23   READ		An error was detected on a tape or disk read.
24   STRING		Illegal string usage.
25   COMMA		Illegal comma or semicolon.
26   OPRND		Illegal Operand.
27   <*mem*>		Out of memory.
28   UNDIM		Undimensioned array referenced.
29   SUBSCPT>>		An array subscript was too large.
30   SUBSCPT OVFLW	Subscript overflow.
31   ASSIGN		An assignment to a non-variable (4=4).
32   STR AS NUM		A string is used where a number is needed.
33   NUM AS STR		A number is used where a string is needed.
34   CNTRL STCK		The control stack is where the following
			items are placed:  return location for
			subroutines & procedures, arguments for
			subroutines & procedures, index variables
			for FOR-NEXT loops.
35   ON GOTO		ON...GOTO, GOSUB index out of limits.
36   <<DATA		Out of Data.
37   RCV DATA		Receive data error.
39   -SQR		The square root of a minus number is illegal.
40   LOGICAL		A true (-1) or false (0) was expected.

The message BASIC IS CRASHED indicates that the BASIC interpreter
has be written into, thus making the interpreter unreliable.

			    A