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Commodore 64 LOGO                  Frames    NoFrames


LOGO INFORMATION

This page gives instructions on how to use Commodore LOGO. Commodore LOGO is a trademark of Commodore Business Machines.

To load logo use the following syntax at the "READY." prompt.

LOAD"LOGO",8     And press [RETURN]

The resonse will be along the lines of

SEARCHING FOR LOGO
LOADING
READY.

Then type

RUN     And press [RETURN]

When loading is complete the following message will appear:

WELCOME TO LOGO!
?

You are now ready to start programming in LOGO !

Type DRAW

The DRAW command will clear the screen and return the LOGO cursor to its original starting position.

To create a procedure that draws a square use the following syntax:

TO SQ
REPEAT 4 [FD 50 LT 50]
END
{Press CONTROL C}

The following will appear on the screen:

SQ DEFINED
?

Now Type SQ to execute the procedure

LOGO should draw a square on the screen

To erase the procedure, type

ERASE SQ

Other commands to use:

[  ] - Short version of command

TURTLE COMMANDS

BACK ## [BK] - Move turtle back
BACKGROUND ## [BG] -
Set Background color (0-15)
0 - Black
1 - White
2 - Red
3 - Cyan
4 - Purple
5 - Green
6 - Blue
7 - Yellow
8 - Orange
9 - Brown
10 - Light Red
11 - Grey 1
12 - Grey 2
13 - Light Green
14 - Light Blue
15 - Grey 3

CLEARSCREEN [CS] - Clear Screen without moving turtle

DRAW - Clear Screen and take turtle home

EACH - Tell several sprites, whose numbers are in a list, to eccept commands in a second list. EG. EACH [1 2] [SQUARE 10]

FORWARD ## [FD] - Move turtle forward

FULLSCREEN - Full graphics screen (same as pressing F5)

HEADING - Output turtle heading as a number (0-359)

HIDETURTLE [HT] - Make turtle invisible

HOME - Move turtle to center of screen pointing up

LEFT [LT] - Turn turtle left

NODRAW [ND] - Enter text mode with clear screen

NOWRAP - Prevent drawings from wrapping around screen

PENCOLOR [PC] - Change pen color

PENDOWN [PD] - Turtle leaves trail

PENUP [PU] - Turtle ceases to leave trail

RIGHT ## [RT] - Turn turtle right

SETHEADING [SETH] - Set turtle heading eg. SETH 180

SETSHAPE - Set the current sprite shape (0-7)

SETX Move the turtle to the specified x co-ordinates Eg. SETX 50

SETXY Move the turtle to the specified x, y co-ordinates Eg. SETXY 50 50

SETY Move the turtle to the specified y co-ordinate Eg. SETY 50

SHAPE - Output number of current sprite's shape

SHOWTURTLE [ST] - Make turtle visible

SPLITSCREEN - Mixed graphics and text screen (same as pressing F3)

STAMPCHAR - Make the turtle stamp a character at the current location Eg. STAMPCHAR "A

TELL - Tell designated sprite to receive commands. EG. TELL 2

TEXTSCREEN - Use whole screen for text (same as pressing F1)

TOWARDS - Output heading for turtle to face an X,Y co-ordinate. Eg. TOWARDS 0 0

WRAP - Make turtle drawings wrap around the screen

XCOR - Output current x co-ordinate of turtle

YCOR - Output current y co-ordinate of turtle

ASPECT - Set verticle screen scale factor, default is 0.76

ARITHMETIC OPERATIONS

a + b
a - b
a * b
a / b
a < b - a less than b (outputs TRUE or FALSE)
a = b - a equals b (outputs TRUE or FALSE)
a > b - a greater than b (outputs TRUE or FALSE)

ATAN - Output the arctangent of side a and b eg. ATAN :A :B
COS - Output cosine of angle expressed in degrees eg. COS 45
INTEGER - Output integer part of input number eg. INTEGER 7.1
NUMBER? - Output TRUE if the input is a number
QUOTIENT - Take two numbers, divide first into second and output integer result eg. QUOTIENT 40 25
RANDOM - Take one input (N) and output random number between 0 and N-1. Random numbers are repeatable eg. RANDOM 50
RANDOMIZE - Make random numbers unrepeatable
REMAINDER - Output the integer remainder, first input modulo the second
ROUND - Output the nearest integer
SIN - Output SINE of angle expressed in degrees
SQRT - Output square root

LIST & WORD OPERATIONS



DEFINING & EDITING PROCEDURES

EDIT - Enter the editor with the procedures title Eg. EDIT CIRCLE
END - Terminate a procedure definition
TO - Define a procedure Eg. TO CIRCLE

VARIABLES

MAKE - Assign the second input to be the value of the first, which must be a word.
eg. MAKE "A 45
     PRINT :A
     45

THING - Output the value associated with the name. Eg. PRINT THING "A is the same as PRINT :A

THING? - Output TRUE if the input has a value associated with it.

CONTROLLING PROCEDURE EXECUTION


CONDITIONALS & FLOW OF CONTROL


INPUT & OUTPUT


FILING & MANAGING WORKSPACE

CATALOG - Print names of disk files

ERASE [ER] Erase the named titles from workspace
ERASE ALL - Erase all procedures from workspace
ERASEFILE - Erase a file from disk Eg. ERASEFILE "MYFILE
ERASEPICT - Erase a picture from disk eg. ERASEPICT "MYPICT
ERNAME - Erase named variable from workspace

PRINTOUT [PO] - Print out commands of procedures in workspace Eg. PO CIRCLE
PRINTOUT ALL - Print out all contents of workspace
PRINTOUT TITLES [POTS] - Print out titles in workspace
PRINTOUT PROCEDURES - Print out procedures in workspace
PRINTOUT NAMES - Print out names in workspace

READ - Read contents of disk file into workspace Eg. READ "PROC1
READPICT - Read a picture file from disk Eg. READPICT "PIC1

SAVE - Save workspace to a file on disk Eg. SAVE "PROC1
SAVEPICT - Save picture on disk Eg. SAVEPICT "PICT1

EDITING COMMANDS

DEL - Delete character
CRSR KEY - Move up, down, left & right

CTRL # - Control Commands
A - Cursor to start of line
B - Cursor back one screen
C - Leave editor and define procedure
D - Delete character at current cursor position
F - Move cursor one screen forward
G - Stop editor without defining procedure
K - Delete to end of line
L - Move cursor to end of line
N - Move cursor down one line
O - Open line for data entry (Insert line)
P - Move cursor up one line
  - Quote next character

OUTSIDE THE EDIT MODE

F1 - TEXTSCREEN
F3 - SPLITSCREEN
F5 - FULLSCREEN Graphics
CTRL G - Stop execution
CTRL H - Stop program execution; any character will resume processing (Pause)
CTRL Z - Pause. Any characters typed will be executed; CONTINUE to restart.

CTRL P - Retrieve previous line typed