BBC Basic Reference Manual

Contents
Part 1 – Overview
	1 About the BBC BASIC Reference Manual
		Intended readership
		Structure of the manual
		Conventions used in this manual
	2 About BBC BASIC
		The BASIC interpreter
		BASIC V and BASIC VI
		BASIC versions
		Window managed programs
Part 2 – Programming techniques
	3 Command mode
		Entering BASIC
		Leaving BASIC
		Command mode
	4 Simple programming
		Entering a program
		Altering a program
		Deleting whole programs
		Numbering lines in a program
		Listing long programs
		Comments
		Multiple statements
		Saving and recalling programs
	5 Variables
		Types of variables
		Naming variables
	6 Numeric expressions
		Integers and floating point numbers
		Special integer variables
		Arithmetic operators
	7 Binary and logic
		Binary numbers and bits
		Hexadecimal numbers
		Shift operators
		AND, OR and EOR
		TRUE and FALSE
	8 String expressions
		Assigning values to string variables
		Joining strings together
		Splitting strings
		How characters are represented
		Converting between strings and numbers
	9 Arrays
		The DIM statement
		Two dimensional arrays
		Finding the size of an array
		Operating on whole arrays
		Array operations
	10 Outputting text
		Print formatting
		The text cursor
		Defining your own characters
	11 Inputting data
		Inputting data from the keyboard
		Including data as part of a program
		Programming the keyboard
		Using the mouse in programs
		Programming function keys
	12 Control statements
		IF... THEN... ELSE
		Operators
		IF... THEN... ELSE... ENDIF
		FOR... NEXT
		REPEAT... UNTIL
		WHILE... ENDWHILE
		CASE... OF... WHEN... OTHERWISE... ENDCASE
		GOTO
		GOSUB... RETURN
		ON... GOTO/GOSUB
	13 Procedures and functions
		Defining and calling procedures
		Parameters and local variables
		ON... PROC
		Recursive procedures
		Functions
		Function and procedure libraries
	14 Data and command files
		Data files
		Writing or reading single bytes
		Writing or reading ASCII strings
		Command files
	15 Screen modes
		Changing screen modes
		Numbered screen modes
		Text size
		Colour modes
		Changing colours
		Changing the colour palette
		VIDC1-style 256-colour modes
		Using the screen under the Wimp
	16 Simple graphics
		The graphics screen
		The point command
		The line command
		Rectangle and rectangle fill
		Circle and circle fill
		Ellipse and ellipse fill
		Graphics colours
		The graphics cursor
		Relative coordinates and BY
		Printing text at the graphics cursor
	17 Complex graphics
		Plotting simple lines
		Ellipses
		Arcs
		Sectors
		Segments
		Flood-fills
		Copying and moving
	18 Graphic patterns
		Default patterns
		Plotting using pattern fills
		Defining your own patterns
		Native mode patterns
		BBC Master mode patterns
		Giant patterns
		Simple patterns
	19 Viewports
		Text viewports
		Graphics viewports
	20 Sprites
		Loading a user sprite
		Plotting a user sprite
	21 Teletext mode
		Coloured text
		Making text flash
		Double-height text
		Changing the background colour
		Concealing and revealing text
		Teletext graphics
	22 Sound
		Activating the sound system
		Selecting sound channels
		Allocating a wave-form to each channel
		Setting the stereo position
		Creating a note
		Synchronising the channels
		Finding the value of the current beat
		Finding the current tempo
		Executing a sound on a beat
	23 Accessing memory locations
		Reserving a block of memory
		The ‘?’ indirection operator
		The ‘!’ indirection operator
		The ‘|’ indirection operator
		The ‘$’ indirection operator
	24 Error handling and debugging
		Trapping an error
		Generating errors
		External errors
		Local error handling
		Debugging
	25 VDU control
	26 Editing BASIC files
		Editing BASIC files with Edit
		Editing BASIC files with the BASIC screen editor
Part 3 – Reference
	27 Keywords
		ABS
		ACS
		ADVAL
		AND
		APPEND
		ASC
		ASN
		ATN
		AUTO
		BEAT
		BEATS
		BGET#
		BPUT#
		BY
		CALL
		CASE
		CHAIN
		CHR$
		CIRCLE
		CLEAR
		CLG
		CLOSE#
		CLS
		COLOUR (COLOR)
		COS
		COUNT
		CRUNCH
		DATA
		DEF
		DEG
		DELETE
		DIM
		DIV
		DRAW
		EDIT
		ELLIPSE
		ELSE
		END
		ENDCASE
		ENDIF
		ENDPROC
		ENDWHILE
		ENVELOPE
		EOF#
		EOR
		ERL
		ERR
		ERROR
		EVAL
		EXP
		EXT#
		FALSE
		FILL
		FN
		FOR
		GCOL
		GET
		GET$#
		GET$
		GOSUB
		GOTO
		HELP
		HIMEM
		IF
		INKEY
		INKEY$
		INPUT
		INPUT LINE
		INPUT#
		INSTALL
		INSTR(
		INT
		LEFT$(
		LEN
		LET
		LIBRARY
		LINE
		LINE INPUT
		LIST
		LISTO
		LN
		LOAD
		LOCAL
		LOG
		LOMEM
		LVAR
		MID$(
		MOD
		MODE
		MOUSE
		MOVE
		NEW
		NEXT
		NOT
		OF
		OFF
		OLD
		ON
		ON ERROR
		OPENIN
		OPENOUT
		OPENUP
		OR
		ORIGIN
		OSCLI
		OTHERWISE
		OVERLAY
		PAGE
		PI
		PLOT
		POINT
		POINT(
		POS
		PRINT
		PRINT#
		PROC
		PTR#
		QUIT
		RAD
		READ
		RECTANGLE
		REM
		RENUMBER
		REPEAT
		REPORT
		REPORT$
		RESTORE
		RETURN
		RIGHT$(
		RND
		RUN
		SAVE
		SGN
		SIN
		SOUND
		SPC
		SQR
		STEP
		STEREO
		STOP
		STR$
		STRING$(
		SUM
		SUMLEN
		SWAP
		SYS
		TAB(
		TAN
		TEMPO
		TEXTLOAD
		TEXTSAVE
		THEN
		TIME
		TIME$
		TINT
		TO
		TOP
		TRACE
		TRUE
		TWIN
		UNTIL
		USR
		VAL
		VDU
		VOICE
		VOICES
		VPOS
		WAIT
		WHEN
		WHILE
		WIDTH
	28 * Commands
		*BASIC
		*BASIC64
		*BASICFPA
		*BASICVFP
	29 ARM assembler
		Using the BASIC assembler
		Saving machine code to file
		Executing a machine code program
		Format of assembly language statements
		Recommended Books
Part 4 – Appendices
	Appendix A – Numeric implementation
		Numeric types
		Effects of storage size
		What is floating point arithmetic?
		Implementation
	Appendix B – Minimum abbreviations
	Appendix C – Error messages
	Appendix D – INKEY values
		INKEY values by functional group
		INKEY values by number
	Appendix E – Specifying screen modes
		Mode Strings
		Mode Variables
	Appendix F – Default palettes
	Appendix G – Plot codes
	Appendix H – VDU variables
	Appendix I – BBC BASIC’s history
Index
	Symbols
	Numerics
	A
	B
	C
	D
	E
	F
	G
	H
	I
	K
	L
	M
	N
	O
	P
	Q
	R
	S
	T
	U
	V
	W