tokens.md

Tokens

The following tokens are used in Retroputer BASIC.

Token	Keyword, Operator, or Meaning
0x00	End of line
0x80	ABS
0x81	AND
0x82	ASC
0x83	ATN
0x84	AT
0x85	CALL
0x86	CATALOG
0x87	CHR$
0x88	CLS
0x89	CLOSE
0x8A	CONTINUE
0x8B	COS
0x8C	DATA
0x8D	DEFFN
0x8E	DEFSUB
0x8F	DIM
0x90	DO
0x91	ELSEIF
0x92	ELSE
0x93	ENDSUB
0x94	ENDFN
0x95	ENDIF
0x96	END
0x97	EXP
0x98	FOR
0x99	GETKEY$
0x9A	GOSUB
0x9B	GOTO
0x9C	HEX$
0x9D	HOME
0x9E	IF
0x9F	INPUT
0xA0	INT
0xA1	IN
0xA2	LEFT$
0xA3	LEN
0xDF	LET
0xA4	LIST
0xA5	LOAD
0xA6	LOG
0xA7	LOOP
0xDD	LOWER$
0xA8	MID$
0xA9	NEW
0xAA	NEXT
0xAB	NOT
0xAC	ON
0xAD	OPEN
0xAE	OR
0xAF	OUT
0xB0	PEEK
0xB1	POKE
0xB2	PRINT, ?
0xB3	READ
0xB4	REM, '
0xB5	RETURN
0xB6	RIGHT$
0xB7	RND
0xB8	RENAME
0xB9	REMOVE
0xBA	RESTORE
0xBB	RUN
0xBC	SAVE
0xBD	SGN
0xBE	SIN
0xBF	SPC
0xC0	SQR
0xC1	STEP
0xC2	STOP
0xC3	STR$
0xC4	TAB
0xC5	TAN
0xC6	THEN
0xC7	TO
0xC8	UNTIL
0xDE	UPPER$
0xC9	USR
0xCA	VAL
0xCB	WHILE
0xCC	+
0xCD	-
0xCE	*
0xCF	/
0xD0	%
0xD1	^
0xD2	<>
0xD3	<=, =<
0xD4	>=, =>
0xD5	<
0xD6	>
0xD7	=
0xD8	(
0xD9	)
0xDA	[
0xDB	]
0xDC	:
0xE0	,
0xE1	;
0xE2	Reserved
0xE3	Reserved
0xE4	Reserved
0xE5	Reserved
0xE6	Reserved
0xE7	Reserved
0xE8	Reserved
0xE9	Reserved
0xEA	Reserved
0xEB	Reserved
0xEC	Reserved
0xED	Reserved
0xEE	Reserved
0xEF	Reserved
0xF0	Reserved
0xF1	Reserved
0xF2	Reserved
0xF3	Reserved
0xF4	Reserved
0xF5	Reserved
0xF6	Reserved
0xF7	Reserved
0xF8	Reserved
0xF9	Floating Point
0xFA	Variable
0xFB	Code String
0xFC	String
0xFD	Long Word
0xFE	Word
0xFF	Byte

Functions

The following function names are reserved:

Function	Signature	Result
ABS	number	Absolute value of number
ASC	$	RetSCII value of the first character in string
ATN	number	Arctangent
CALL	fn, ...params	Call a function
CHR$	number	Character corresponding to the number
COS	number	Cosine
EXP	number	Exponential
GETKEY$	N/A	Character of last key press
HEX$	number	String representation of number in hexadecimal
INT	number	Integer portion of the number
IN	port:number	Returns the data on the given port (0x00-0xFF)
LEFT$	$, length:number	Returns the first number of characters in a string
LEN	$	Returns the length of the string
LOG	number	Logarithm
LOWER$	$	Lowercase version of string
MID$	$, s:#, l:#	Returns portion of string at s for l chars
PEEK	bank:#, addr:#	Returns memory at given bank and address
RIGHT$	$, length:number	Returns right portion of string
RND	number	Returns next random number within range of #
SGN	number	Returns -1 if number is negative; 1 if postive; 0 if zero
SIN	number	Sine
SPC	number	Move cursor right by a given number of spaces
SQR	number	Square root
STR$	number	String representation of the given number
TAB	number	Move cursor right by given number of tabs
TAN	number	Tangent
USR	a:#, ...params	Call machine language at address
VAL	$	Number represented by the string

Operators

The following operators are reserved:

Operator	Precedence	Result
AND	0x06	Bitwise AND
NOT	0x11	Bitwise NOT
OR	0x05	Bitwise OR
+	0x0E	Addition
-	0x0E	Subtraction
*	0x0F	Multiply
/	0x0F	Divide
%	0x0F	Modulo
^	0x10	Power
<>	0x0B	1 if Unequal; else 0
<=	0x0C	1 if lhs is less than or equal to rhs; else 0
>=	0x0C	1 if lhs is greater than or equal to rhs; else 0
<	0x0C	1 if lhs is less than rhs; else 0
>	0x0C	1 if lhs is greater than rhs; else 0
=	0x0B	1 if equal; else 0
(...)	0x15	Array index, Parameter list
[...]	0x14	Array index? (@todo)
,	0x01	Separator

Keywords

The following keywords are reserved:

Keyword	Signature	Result
AT	x:#, y:#	Position cursor at given position. Valid only w/ PRINT and INPUT
CALL	sub, ...params	Call a subroutine
CATALOG		Display catalog of BASIC programs on storage
CLS		Clear screen
CLOSE	channel:#	Close given channel
CONTINUE		Continue program execution where it left off
DATA	...values	Define data values
DEFFN	name (params)	Define a function; return type is determined from the sigil
DEFSUB	name (params)	Define a subroutine
DIM	name(size)	Declares an array of specified size and type
DO	Block	Executes a block in a loop
ELSEIF	expr Block	Evalutes expression and executes Block if it is 1
ELSE	Block	Executes Block if previous IF was false
ENDSUB		Ends a subroutine
ENDFN		Ends a function
ENDIF		Ends a multi-line IF
END		Stops program execution
FOR		Starts a FOR loop
GOSUB	number	Calls a subroutine at the line number
GOTO	number	Jumps to the line number
HOME		Sets cursor to top left position
IF	expr Block	Evaluates expression and if 1, evaluates the then bock
INPUT	`...$	name
LET	name=expr	Assigns result of expression to variable
LIST	[s:#[,f:#]]	Lists a program, optionally with a range
LOAD	$	Loads a program with the given name
LOOP		Repeats inverted UNTIL
NEW		Resets BASIC, erasing the current program
NEXT	[name]	Returns to the nearest FOR
ON	`# GOTO	GOSUB...#`
OPEN	c:#, $	Opens a channel with name
OUT	port:#, #	Outputs a value to the given port
POKE	b:#, a:#, #	Writes a value to the given bank/address
PRINT,?		Prints data
READ	...names	Reads data into variables
REM		Comment
RETURN		Returns from a subroutine. In a function, can return a value
RENAME	$ TO $	Renames a file
REMOVE	$	Removes a file
RESTORE	[number]	Restores DATA pointer to start (or line number)
RUN	[number]	Starts execution at start (or line number)
SAVE	$	Saves program to file
STEP	number	Controls increment/decrement in FOR
STOP		Stops execution and displays a STOPPED error.
THEN	Block	Executes block if IF expression was 1
TO		Used in FOR and RENAME
UNTIL	expr	Repeats DO until the expression is 1
WHILE	expr	Repeats DO while the expression is 1