Alphabetical List of Commands Table of Contents
A B C D E F G H I J K L M
N O P Q R S T U V W X Y Z
Comparison Number Prefixes
A Top
ABS reports the absolute value of a number
ACTIVEWINDOW reports the name of the active graphics window
AGET retrieves an array element
ALERT displays an alert box
ALIAS defines an alias name
ALLTURTLES outputs a list of all turtles
AND performs a logical AND
APPENDMENU appends a new menu
APPENDMENUCOMMAND appends a new menu item and attaches it to a Logo command list
APPENDMENUITEM appends a new menu item and defines a menu item ID
APPLY applies a parameter list to a procedure
"AQUA a color name
ARCCOS (ACOS) reports the arccosine
ARCCOT (ACOT) reports the arccotangent
ARCCSC (ACSC) reports the arccosecant
ARCSEC (ASEC) reports the arcsecant
ARCSIN (ASIN) reports the arcsine
ARCTAN (ATAN) reports the arctangent
ARRAY creates an array
ARRAY? checks for a name being an array
ARRAYDIMS outputs the dimension list of an array
ASCII converts a character into its ASCII value
ASET stores an array element
ASK runs a list of commands for a specific object
B Top
BACK move the turtle backwards
BACKGROUND (BG) outputs the background color
BACKTRACE (BT) prints a backtrace in the debugger window
:BASE sets the numeric base used when printing numbers
BASECOLOR coerces a color value to a basic Logo color number
BEEP causes the RCX device to beep
BGPATTERN reports the background pattern
"BLACK a color name
"BLUE a color name
"BROWN a color name
"BROWNISH a color name
BURIEDNAMES reports a list of all buried names
BURIEDPROCS reports a list of all buried procedures
BURIEDPROPS reports a list of all buried properties
BURY buries a Logo name and its contents
BURYALL buries evetything in the workspace
BURYNAME buries a name
BURYPROC buries a procedure definition
BURYPROP buries a property
BUTFIRST (BF) strips off the first elements of its input
BUTLAST (BL) strips off the last element of its input
BUTMEMBER (BM) removes an element from its input
BUTTON? reports the state of the (left) mouse button
BYE prompts to exit Logo
BYTEARRAY creates a bytearray
BYTEARRAY? check for a name being a bytearray
C Top
:CASE controls how user input is converted
CATCH catches runtime errors
CHAR converts a number into a character
CLEAN erases the graphics screen
CLEARINPUT clears all input from a stream
CLEARSCREEN (CS) clears the graphics window
CLEARTEXT (CT) clears the Listener window
CLOSEWINDOW closes a window
COLORPICKER the color picker window
COLORS outputs a list of available color names
COMMAND executes a menu command by ID
COMPUTE performs a variable computation inside the RCX device
CONFIGURE configure a serial port
CONTENTS outputs a list of all Logo names
CONTINUE continues the execution of a Logo program
COPYDEF copies a procedure definition
COS reports the cosine
COT reports the cotangent
COUNT counts the number of items in its input
CREATE creates a file
CSC reports the cosecant
CTURTLES activates the specified number of turtes and arranges them in a circle
CURDIR outputs the current working directory
:CURRENT.GRAPHICS The currently active graphics window (read only)
:CURRENT.WINDOW The currently active window
"CYAN a color name
D Top
"DARKBLUE a color name
"DARKGREEN a color name
"DARKRED a color name
:DATADIR the Logo data directory
DATE reports the date
DECLARE (DCL) creates an object
DEFINE defines a procedure
DEFINED? checks whether a procedure is defined
DELETE deletes a file
DELETEMENU deletes a menu
DELETEMENUITEM deletes a menu item
DIFFERENCE (-) outputs the difference of two or more numbers
DIRECTORY outputs a directory listing
DISCARD discards pending input
DISTANCE reports the distance between the turtle and a location
DOT paints a dot
DOT? checks whether a dot is present at the turtle's position
DOTCOLOR reports the color of the dot underneath the turtle
DOWNLOAD downloads a program to the RCX device
DRAW clears the graphics window and resets the turtles
E Top
EACH applies a runlist to every element of a list
EDIT edits a Logo name
EDITSHAPE edits a turtle shape
EDL opens the visual list editor with the contents of the specified list displayed
EDN edits Logo names
EDP opens the property editor for a Logo name
ELSE part of the IF command
EMPTY? checks whether a name is empty
END ends a procedure definition
EOF? outputs TRUE if the current stream ist at EOF
EQUAL? tests two objects for equality
ERASE erases a Logo name
ERN erases all names
:ERROR contains the code of the last runtime error
:ERRORTEXT contains the text of the last runtime error
EVERY outputs a list of objects
EXIT prompts to exit Logo
EXPN calculates the natural base e raised to a power
EXTENT reports the coordinate extent of a turtle
F Top
FENCE fences all turtles inside the window
FILE.INFO reports information about a file
FILE? checks for the presence of a file
FILL fills an area
FILLARRAY fills an array with values
FINDMENUID find the ID for a menu item
FIRST reports the first element of its input
FONT reports the current turtle font
FONTS outputs a list of all available fonts
FOR runs a list for a defined number of times
FOREACH runs a list for each element of a list replacing ? with the element name
FORWARD moves the turtle forward
FPUT prepends an element to its input
FROMMEMBER (FM) removes the first part of its input until a pattern is found
FULLSCREEN (FS) maximizes the current Graphics window
G Top
GETBYTE reads one byte fomr the input stream
GETSTEPSIZE obtains the current step size for the specified object
GETXY reports the turtle's position
GLIST reports the property lists that contain a property with a given name
GO jumps to a label inside a procedure
"GOLD a color name
GPROP retrieves a property
GRAPHICS the name of the first graphics window
"GRAY a color name
"GREEN a color name
GRID sets the grid scale
GRIDOFF makes a visible grid invisible
GRIDON makes a grid visible in the Graphics window
H Top
HALT halts background procedures
HEADING reports the heading of the turtle
HELP displays help for a command
HIDETURTLE (HT) hides the turtle
HIT? tests whether a dot or an object touches another object
HOME moves the turtle back to [0 0]
I Top
IF runs a list based on a condition
IFFALSE (IFF) runs a list if TEST was false
IFTRUE (IFT) runs a list if TEST was true
IGNORE ignore the output of a procedure
INT reports the integer part of a number
IS.A check an object for being of a specific type
ITEM returns a specific element of its input
K Top
KEY returns a key typed at the keyboard
L Top
LABEL marks a target for the GO command
LAST reports the last element of its input
LAUNCH launches a background procedure
LEFT turns the turtle left
LIGHT turns a light on a robot device on or off
LIGHT? checks whether a light on a robot device is on or off
"LIME a color name
LIST concatenates its inputs to a list
LIST? checks for its input being a list
LISTARRAY outputs the contents of an array as a list
LISTENER the name of the listener window
LOAD loads workspaces
LOADENV loads environments
LOADLOG uploads the RCX log
LOADPIC loads a picture
LOADSHAPE loads a turtle shape
LOADSNAP loads a bitmap
LOCAL declares local variables inside a procedure
LOCKSHAPE inhibits the turtle shape from turning
LOG outputs the natural logarithm of its input
LOG10 outputs the logarithm of its input
LOGAND combines its inputs with a boolean AND operation
LOGNOT inverts the bits of its input
:LOGODIR reports the directory where the Logo program is in
LOGOR combines its inputs with a boolean OR operation
LOGXOR combines its inputs with a boolean XOR operation
LOWERCASE converts its argument to lower case
LPUT appends an element to its input
LSH left-shifts its input
LTURTLES activates the specified number of turtles and arranges them in a line
M Top
"MAGENTA a color name
MAKE assigns a value to a name
MEMBER? checks for an element being a member of its input
MIXEDCASE converts its argument to mixed case
MOTOR turns a motor on or off
MOTOR? check whether a motor is turned on
MOUSE reports the position of the mouse cursor
MOUSESHAPE reports the shape of the mouse cursor
N Top
NAME assigns a value to a name
NAME? checks whether its input is assigned a value
NAMELIST outputs a list of all defined names
"NAVY a color name
NEW creates a new Logo object
NODES estimates the number of available Logo nodes
NOT negates its input
NOT.EQUAL? tests its inputs for inequality
NUMBER? checks its input for being a number
NXT.CLOSE closes the connection to the NXT device
NXT.IOMAP.READ reads the specified IO map on the NXT device
NXT.OFF turns off the NXT device
NXT.OPEN opens the connection to the NXT device
NXT.PORTS supplies a list of available communication ports for the NXT device
O Top
ONCOMMAND defines a Logo runlist for a menu ID
OPEN opens a file
OPEN.OUTPUT opens an Output window
OPEN.PORT opens a serial port
OR performs a logical OR on its input
"ORANGE a color name
ORIGIN reports the origin of a turtle's coordinate system
OUTPUT (OP) halts a procedure and outputs a value
P Top
PANGLE reports the polar angle
PARSE parses a string and outputs a list
PATTERN reports the turtle's pattern
PAUSE opens the Debugger window
PDIST calculates the polar distance
PEEKBYTE reports the next byte of the input stream without reading it
PEN reports the pen mode
PENCOLOR (PC) outputs the pen color
PENDOWN (PD) puts the pen down
PENDOWN? checks whether the pen is down
PENERASE (PE) the pen draws with the background color
PENREVERSE (PX) the pen inverts all colors
PENUP (PU) the pen moves up
PHEADING reports the polar heading
PI reports the number Pi
PICK randomly picks an element
:PICTURE.FORMAT contains the format for storing pictures in
"PINK a color name
PLAY plays sounds
PLIST reports the property list of a name
PONS prints all values
POPLS prints all property lists
POPRS prints all primitives
POPS prints all user-defined procedures
POS reports the position of the turtle
POTS prints the headings of all user-defined procedures
POWER (^) raises a number to the power of another number
PPOS reports the turtle's polar position
PPROP stores a property
PPROPS stores a list of properties
:PRECISION sets the precision in which numbers are printed
PREFS contains all preference properties
PRIMITIVE? checks its input for being a built-in procedure
PRINT (PR) prints its inputs and a newline
PRINTLINE prints a list of numbers as ASCII characters
PRINTOUT prints procedures, values, or properties
PRINTQUOTE (PQ) prints its input and a newline
PROCEDURE? checks its input for being a user-defined procedure
PROCLIST outputs a list of all user-defined procedures
PRODUCT (*) calculates the product of its inputs
PSETHEADING sets the polar heading of a turtle
"PURPLE a color name
PUTBYTE writes a data byte to the output stream
PUTBYTES writes data bytes to the output stream and reads a reply
Q Top
QUIT prompts to exit Logo
QUOTE quotes its input
QUOTIENT (/) reports the quotient of its inputs
R Top
RANDOM outputs a random number
.RCX outputs low-level commands to the RCX device
RCX.CLOSE closes the communications channel to the RCX device
RCX.HALT terminates any running program inside the RCX device
RCX.LAUNCH launches a progrm inside the RCX device
RCX.LOG adds an entry to the internal RCX log
RCX.NAMES defines names for RCX variables
RCX.OPEN establishes communication to the RCX device
RCX.PANEL displays the RCX control panel
RCX.PLAY plays a melody inside the RCX
RCX.POLL polls the RCX
READ reads one Logo word
READCHAR (RC) reads a character
READLINE reads a line and outputs it as a list of numbers
READLIST reads a line and outputs it as a list
READPROMPT (RP) opens a dialog box and reads a line
READQUOTE reads a line
READWORD reads the first word of a line
RECYCLE starts the garbage collector
"RED a color name
REMAINDER outputs the remainder of two numbers
REMPROP removes a property
RENAME renames a file
REPEAT runs a runlist repeatedly
RERANDOM seeds the randum number generator
RESTART restarts Logo and sets all defaults
RIGHT turns the turtle right
ROBOT activates a robot device
ROBOT.CLOSE terminates the communication to a robot device
ROBOT.OPEN activates a robot device
ROBOT.PANEL display the Robot Control Panel
ROBOTFACTS outputs charactertistcs about the robot device
ROUND rounds a number
RUN runs a list
S Top
SAVE saves the workspace
SAVEENV saves the environment
SAVEPIC saves the contents of a graphics window
SAVESHAPE saves a turtle shape
SAVESNAP saves a bitmap
SEC reports the secant
SENSOR reads the value of a robot sensor
SENTENCE combines its inputs to a list, flattening lists
SETACTIVEWINDOW (SETACTIVEW) sets the name of the active window
SETBG sets the background color
SETBGPATTERN sets the background pattern
SETCURDIR sets the current working directory
SETDISPLAY defines the variable to be displayed in the RCX
SETEXTENT sets the coordinate system extent of a turtle
SETFONT sets the font of a turtle
SETHEADING sets the heading of a turtle
SETLOGSIZE defines the size of the internal RCX log
SETMOUSESHAPE sets the shape of the mouse cursor
SETORIGIN sets the origin of the coordinate system of a turtle
SETP sets the polar position of a turtle
SETPATTERN sets the turtle pattern
SETPC sets the pen color
SETPEN sets the pen characteristics
SETPOS sets the position of a turtle
SETSENSOR defines the characteristics of a RCX device sensor
SETSHAPE sets the turtle shape
SETSPEED Sets the speed in which turtle commands are executed
SETSTEPSIZE Sets the step size for the specified object
SETTURTLENAME (SETTNAME) defines a name for a turtle
SETTURTLES defines a number of turtles
SETTURTLESIZE (SETTSIZE) sets the size of a turtle
SETVELOCITY Sets the independent movement speed of the turtle
SETWIDTH sets the pen width
SETTWINDOW attaches all active turtles to a window
SETWINSIZE sets the size of a window
SETWPOS sets the position of a window
SETX sets the X coordinate of a turtle
SETXY sets the position of a turtle
SETY sets the Y coordinate of a turtle
SHAPE outputs a bitmap
SHOW prints its inputs
SHOWN? checks whether a turtle is visible
SHOWTURTLE (ST) shows a turtle
"SILVER a color name
SIN reports the sine
SLOWTURTLE Slows the speed in which turtle commands are executed
SNAP moves parts of the graphics window into a bitmap
SNAPSIZE outputs the size of a bitmap
SPEED Retrieves the speed in which turtle commands are executed
SPLITSCREEN Restores the Listener and Graphics window layout
SQRT reports the square root
STAMP draw a bitmap
STAMPOVAL draws an oval
STAMPRECT draws a rectangle
:STANDARD.INPUT the number of the input stream
:STANDARD.OUTPUT the number of the output stream
STEPSIZE sets movement distance for turtles and bitmaps
STOP terminates a procedure
SUBST subtitutes text in a word or a list
SUM (+) reports the sum of its inputs
SWITCH? checks the state of a switch of a robot device
T Top
:TAB sets the tab stop position
TELL defines a list of objects listening to commands
TELLALL tells a range of turtle nubmers
TELLEVEN tells all turtles with even numbers
TELLODD tells all turtles with odd numbers
TEST test a condition. Used with IFTRUE and IFFALSE
TEXT outputs a procedure definition
TEXTARRAY converts the contents of a bytearray into a word
TEXTSCREEN maximizes the Listener window
THEN part of the IF command
THING reports the value of a name
THROW throws a runtime error
TIME outputs the time
TO opens the procedure defintion window
TOOLBAR the name of the toolbar window
TOOLBOX the name of the toolbox window
TOPLEVEL returns to toplevel
TOWARDS reports the angle of a position compared to the turtle position
:TRACE causes trace output to the Listener
TURTLENAME (TNAME) reports the name of a turtle
TURTLENAMES (TNAMES) output s a list of all known turtle names
TURTLES outputs a list of all turtles
TURTLESIZE reports the size of a turtle
TURTLETEXT (TT) lets the turtle print a text
TWINDOW outputs the name of the window of the first active turtle
TYPE prints its inputs
TYPEOF reports the type of a name
U Top
UNBURY unburies a name
UNBURYALL unburies all names
UNBURYNAME unburies a value
UNBURYPROC unburies a procedure definition
UNBURYPROP unburies a property
UNGETBYTE pushes back one byte to the input stream
UNLOCKSHAPE lets a turtle shape rotate according to the turtle's heading
UPPERCASE converts its argument to upper case
:USERNAME contains the login name of the user
V Top
VELOCITY Retrieves the independent movement speed of the turtle
VERSION (VER) outputs the Logo version and computer operating system
W Top
WAIT waits for a number of milliseconds
WHILE runs a list until a condition is false
"WHITE a color name
.WHO reports a list of objects listening to commands
WHO reports a list of objects listening to commands
WIDTH reports the pen width
WINDOW removes the boundary for turtle movements
.WINDOWS Call the Windows API (Windows version only)
WINSIZE reports the size of a window
WORD concatenates its inputs to a word
WORD? checks its input for being a word
WORKSPACE contains the workspace size and the number of colors
WORKSPACE.VIEW displays the Workspace View dialog
WPOS outputs the position of a window
WRAP lets the turtles wrap inside the window
X Top
XCOR reports the X coordinate of the turtle's position
Y Top
"YELLOW a color name
YCOR reports the Y coordinate of the turtle's position
Comparison Top
.EQ (=) tests for equality
.NE (!= <>) tests for inequality
.GT (>) tests for its first input being greater than its 2nd input
.GE (>=) tests for its first input being greater than or equal to its 2nd input
.LT (<) tests for its first input being less than its 2nd input
.LE (<=) tests for its first input being less than or equal to its 2nd input
Number Prefixes Top
#B binary numbers
#D decimal numbers
#H hexadecimal numbers
#O octal numbers