logo_commands

TERRAPIN LOGO FOR MACINTOSH

commands arranged alphabetically
commands grouped by function
sample procedures (transformers)

Commands arranged alphabetically

+-*/

math operations

ABS number

absolute value of number

BACK number

BK

moves turtle opposite direction

CLEAN

erases all graphics, does not affect turtle heading

CLEARGRAPHICS [

CG

clears current graphics, puts turtle home

COS number

cosine of angel measured in degrees

DISTANCE x y

determines distance to indicated position

EDIT

ED

Edits a file: edit "filename

END

terminates procedure

EXP number

inverse function of LN, e 2.7128

FILLSH [commands]

fills graphics region with pen pattern

FORWARD number

FD

moves turtle forward

HEADING

outputs heading from 0 to 360 degrees

HIDETURTLE

HT

make current turtle cursor disappear

HOME

moves cursor to home position

LEFT number

LT

turns left specified number of degrees

LN number

natural logarithm

LOAD filename

loads filename from memory

MAKE name value

make "varname value; assigns values to variable

NOWRAP

Allows turtle to move beyond boundary

PENDOWN

PD

puts pendown

PENERASE

PE

turns pen into eraser mode

PENPAINT

paints with current pen pattern and size

PENUP

PU

raises pen

POS

Outputs the turtles x and y coordinates

POTS

prints out titles of procedures

RANDOM number

random

REPEAT number [procedure]

repeat procedure specified number of times

RIGHT

RT

turns turtle to the right specified number of degrees

SAVE filename

saves filename

SETHEADING number

SETH

Rotates turtle to specified heading

SETPENMODE number

uses 0 to 7 as input, affects pattern

SETPENSIZE height width

SETPS

0 to 255 range

SETPPATTERN number

SETPP

1-38 patterns

SETXY x y

positions cursor with x and y coordinates

SIN number

sine of angel measured in degrees

SQRT number

square root of number

STAMPARC xradius yradius deg

creates an arc

STAMPOVAL width height

creates oval

STAMPRECT width height

creates rectangle

TO

define a procedure

TO procedure :x :y

defines a procedure with variables :x and :y

TOWARDS x y

outputs heading toward point

WRAP

wraps graphics within window

Commands Grouped by Function

QUOTIENT

math operations

Outputs integer of division of first divided by second

REMAINDER

math operations

outputs just the remainder of division, dropping the integer

RUN

math operations

executes the items in RL, especially if it is an equation

SIN

math operations

outputs the sine of angle expressed in degrees

SQRT

math operations

outputs the square root of input

SUM

math operations

adds two numbers which follow it together

PRINT (PR [data])

output

prints out specified data

TYPE

output

similar to PRINT but cursor doesn't move to next line

BacK (BK)

pen commands

Moves turtle a specified number of steps backwards

ForwarD (FD)

pen commands

Moves the turtle forward a specified number of steps

HideTurtle (HT)

pen commands

makes the turtle turn invisible

HOME

pen commands

moves the turtle to the origin (0,0) in the middle

LefT (LT)

pen commands

Turns the turtle a specified number of degrees to the left

PenDown (PD)

pen commands

puts pen down so that line is drawn when turtle is moved

PenErase (PE)

pen commands

pen acts like an eraser in this mode

PenUp (PU)

pen commands

lifts pen so no line is drawn when the turtle is moved

RighT (RT)

pen commands

turns the turtle a specified number of degrees to the right

SETHeading (SETH)

pen commands

Points the turtle in specified direction from 0 to 360 deg.

ShowTurtle (ST)

pen commands

shows turtle; important to get started

.Printer 0

printer

turns printer off

.PRINTER 1

printer

sends text to printer (in slot 1) rather than screen

EDit (ED)

procedures

Allows you to enter the EDIT mode to make procedures

END

procedures

Defines the end of a procedure

REPEAT # [procedure]

procedures

Causes procedure to be repeated specified number of times

TO (procedure name)

procedures

Signals the beginning of procedure

CLEAN

screen display

Erases all graphics but leaves turtle at last location

ClearScreen (CS)

screen display

Erases all graphics and puts turtle at origin (0,0) again

FENCE

screen display

Prevents turtle from exiting screen; terminates procedure

Fullscreen (Control-L)

screen display

gives full screen of graphics, no text

PEN

screen display

Outputs the state and color of the pen

SETBackGround (SETBG)

screen display

Sets background colors : 0-BK; 1-W; 2-G; 3-V; 4-O; 5-B

SETPenColor (SETPC)

screen display

Sets color of pen : 0-BK; 1-W; 2-G; 3-V; 4-O; 5-B

Splitscreen (Control-S)

screen display

gives graphics and text on same screen

Textscreen (Control-T)

screen display

Gives a full screen of text with no graphics

WINDOW

screen display

Allows turtle to leave screen but won't wrap around

WRAP

screen display

When turtle goes of screen it will wrap around on other side

PRint (PR [text])

text

prints out text specified in brackets

WAIT (# of 60ths of sec)

text

Delays next output by specified time

MAKE "varname varvalue

variable definition

defines vairable name to have a specific value

ERase (ER) "procedure name

workspace

erases specific procedure from workspace

ERaseALL (ERALL)

workspace

Erases all procedures in workspace

PrintOutTitleS (POTS)

workspace

Prints out titles of all procedures in workspace

SAMPLE TRANSFORMER PROCEDURES

LOGO PROCEDURES WRITTEN BY STEVE LEGE
transformers: a logo microworld
the computer teacher
may 1986; pp 33-37

For classroom use: You may copy this code from this word processor file directly into Logo and run it.

TO START
make "a 1
make "s 30
setpc 1
end

TO AXES
start
clearscreen
penup setpos [-140 0] pendown
setheading 90
fd 275
penup setpos [0 -119] pd
setheading 0
penup setpos [50 50] pendown
end

TO REFLECT.H
make "x -xcor
make "y ycor
make "h -heading
make "a -:a
penup setpoos se :x :y pendown
setheading :h
setpc 3
end

TO REFLECT.V
make "y -ycor
make "x xcor
if (or heading<180 heading=180) [make "h 180-heading]
if heading>180[make "h 540-heading]
make "a -:a
setheading :h
setpc 3
end

TO ROTATE :D
right :d
setpc 3
end

TO TRANSLATE :X :Y
penup
setpos se :s :y
pendown
setpc 3
end

TO RATIO :N
make "s :n*:s
setpc 3
end

TO REMEMBER
make "orig.s :s
make "origi.x xcor
make "origi.y ycor
make "origi.a :a
make "orig.h heading
end

TO REPLACE
setpos se :orig.x orig.y
setheading :orig.h
setpc 1
pendown
make "a :orig.a
make "s :orig.s
end

TO BOX
repeat 2[fd :s rt 90*:a fd :s*2 rt 90*:a]
mark
end

TO MARK
repeat 4[fd 6 rt 90*:a]
end

TO RT.TRI
fd :s rt 120*:a
fd :s*2 rt 150*:a
fd :s*1.73 rt 90*:a
mark
end

TO SQ
pu bk :s/2 lt 90*:a pd
fd :s/2 rt 90*:a]
mark
repeat 3 [fd :s rt 90*:a]
fd :s/2 rt 90*:a
pu fd :s/2 pd
end

TO PENTA
pu bk :s/2*1.37 pd
lt 90 * :a mark
fd :s/2 rt :a*72
repeat 2 [fd :s rt 72*:a]
lt 72*:a
repeat 3[rt 120*:a fd 9]
rt 72*:a
repeat 2[fd :s rt 72 * :a]
fd :s/2 rt 90 * :a
pu fd :s/2 * 1.37 pd
end

TO TEE
pu lt 90 * :a fd 5 pd
fd 25 rt 90*:a
mark
fd 10 rt 90*:a
fd 60 rt 90*:a
fd 10 rt 90*:a
fd 25 lt 90*:a
fd 40 rt 90*:a
fd 10 rt 90*:a
fd 40 rt 90*:a
pu fd 5 lt 90*:a pd
end

+-*/		math operations
ABS number		absolute value of number
BACK number	BK	moves turtle opposite direction
CLEAN		erases all graphics, does not affect turtle heading
CLEARGRAPHICS [	CG	clears current graphics, puts turtle home
COS number		cosine of angel measured in degrees
DISTANCE x y		determines distance to indicated position
EDIT	ED	Edits a file: edit "filename
END		terminates procedure
EXP number		inverse function of LN, e 2.7128
FILLSH [commands]		fills graphics region with pen pattern
FORWARD number	FD	moves turtle forward
HEADING		outputs heading from 0 to 360 degrees
HIDETURTLE	HT	make current turtle cursor disappear
HOME		moves cursor to home position
LEFT number	LT	turns left specified number of degrees
LN number		natural logarithm
LOAD filename		loads filename from memory
MAKE name value		make "varname value; assigns values to variable
NOWRAP		Allows turtle to move beyond boundary
PENDOWN	PD	puts pendown
PENERASE	PE	turns pen into eraser mode
PENPAINT		paints with current pen pattern and size
PENUP	PU	raises pen
POS		Outputs the turtles x and y coordinates
POTS		prints out titles of procedures
RANDOM number		random
REPEAT number [procedure]		repeat procedure specified number of times
RIGHT	RT	turns turtle to the right specified number of degrees
SAVE filename		saves filename
SETHEADING number	SETH	Rotates turtle to specified heading
SETPENMODE number		uses 0 to 7 as input, affects pattern
SETPENSIZE height width	SETPS	0 to 255 range
SETPPATTERN number	SETPP	1-38 patterns
SETXY x y		positions cursor with x and y coordinates
SIN number		sine of angel measured in degrees
SQRT number		square root of number
STAMPARC xradius yradius deg		creates an arc
STAMPOVAL width height		creates oval
STAMPRECT width height		creates rectangle
TO		define a procedure
TO procedure :x :y		defines a procedure with variables :x and :y
TOWARDS x y		outputs heading toward point
WRAP		wraps graphics within window

QUOTIENT	math operations	Outputs integer of division of first divided by second
REMAINDER	math operations	outputs just the remainder of division, dropping the integer
RUN	math operations	executes the items in RL, especially if it is an equation
SIN	math operations	outputs the sine of angle expressed in degrees
SQRT	math operations	outputs the square root of input
SUM	math operations	adds two numbers which follow it together
PRINT (PR [data])	output	prints out specified data
TYPE	output	similar to PRINT but cursor doesn't move to next line
BacK (BK)	pen commands	Moves turtle a specified number of steps backwards
ForwarD (FD)	pen commands	Moves the turtle forward a specified number of steps
HideTurtle (HT)	pen commands	makes the turtle turn invisible
HOME	pen commands	moves the turtle to the origin (0,0) in the middle
LefT (LT)	pen commands	Turns the turtle a specified number of degrees to the left
PenDown (PD)	pen commands	puts pen down so that line is drawn when turtle is moved
PenErase (PE)	pen commands	pen acts like an eraser in this mode
PenUp (PU)	pen commands	lifts pen so no line is drawn when the turtle is moved
RighT (RT)	pen commands	turns the turtle a specified number of degrees to the right
SETHeading (SETH)	pen commands	Points the turtle in specified direction from 0 to 360 deg.
ShowTurtle (ST)	pen commands	shows turtle; important to get started
.Printer 0	printer	turns printer off
.PRINTER 1	printer	sends text to printer (in slot 1) rather than screen
EDit (ED)	procedures	Allows you to enter the EDIT mode to make procedures
END	procedures	Defines the end of a procedure
REPEAT # [procedure]	procedures	Causes procedure to be repeated specified number of times
TO (procedure name)	procedures	Signals the beginning of procedure
CLEAN	screen display	Erases all graphics but leaves turtle at last location
ClearScreen (CS)	screen display	Erases all graphics and puts turtle at origin (0,0) again
FENCE	screen display	Prevents turtle from exiting screen; terminates procedure
Fullscreen (Control-L)	screen display	gives full screen of graphics, no text
PEN	screen display	Outputs the state and color of the pen
SETBackGround (SETBG)	screen display	Sets background colors : 0-BK; 1-W; 2-G; 3-V; 4-O; 5-B
SETPenColor (SETPC)	screen display	Sets color of pen : 0-BK; 1-W; 2-G; 3-V; 4-O; 5-B
Splitscreen (Control-S)	screen display	gives graphics and text on same screen
Textscreen (Control-T)	screen display	Gives a full screen of text with no graphics
WINDOW	screen display	Allows turtle to leave screen but won't wrap around
WRAP	screen display	When turtle goes of screen it will wrap around on other side
PRint (PR [text])	text	prints out text specified in brackets
WAIT (# of 60ths of sec)	text	Delays next output by specified time
MAKE "varname varvalue	variable definition	defines vairable name to have a specific value
ERase (ER) "procedure name	workspace	erases specific procedure from workspace
ERaseALL (ERALL)	workspace	Erases all procedures in workspace
PrintOutTitleS (POTS)	workspace	Prints out titles of all procedures in workspace