Elmer the Turtle

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Elmer the Turtle
The start screen.
Developer Peter Crosby
Publisher RUN magazine
Release 1986
Plattform C64
Genre Programming Language Logo
Operation C64-icon.png
Media Icon disk525.png, Listing
Language Language:english
Information

Elmer the Turtle is a very easy programming tool for LOGO or learning and understanding programming on a computer, that was first published in RUN magazine issue September 1986[1]. The program was developed by Peter Crosby in BASIC for the C64. The output of the turtle are only BASIC chars!

Description[edit]

"Elmer the Turtle" has a small input mask, which is limited to 36 lines.

You have the following options:

  • Input a line number from 1 until 36 for editing a line.
  • Input E for starting Elmer, who is executing the input commands on the second screen (this is equal with a program start).
  • Input the command NEW for deleting the whole input mask.

After that, don't forget to press RETURN !


Editing a line

If you have input a line number from 1 until 36, you see all the 10 commands of Elmer the turtle. You can also input a command, which contains the command word and a parameter like number, char or text. The command input is closing by pressing RETURN . If you have successful input a command, you go back to the input mask.

Also you have 3 special commands:

  • I : Insert a line at this line position.
  • D : Delete this line.
  • B : Back to line #. This leave the editing line mode and you are go back to the input mask.

Start & Instructions[edit]


The starting screen of "Elmer the Turtle".
The short instructions for "Elmer the Turtle".




Commands[edit]

Editing the first line.
A small demo program.
The excuted program.

The program "Elmer the Turtle" knows 13 commands.


Turtle (Elmer) commands
RIGHT X : Move Elmer X chars right. X = 0-99

LEFT X : Move Elmer X chars leftt.

UP X : Move Elmer X chars up. 

DOWN X : Move Elmer X chars down.
               - Note: If Elmer leave the screen, he comes back from the other side!

PEN UP : Deactivate the pen (no painting!). No chars will be permanent shown on screen.

PEN DOWN : Activate the pen for painting. All chars will be permanent shown on screen.

CHAR Z: Change the drawing char Z (no graphic symbols allowed!).

TEXT ABC: Write the text ABC (min. 1, max. 10 chars long). It could be also used graphic symbols!

COLOR C : Change the painting color C = 0-15.

STOP : Stop Elmers moving and painting. The program holds on and you see the drawing screen. 
       You go back to the input mask after pushing a key.


Editing / special line commands
INSERT : empty line by input: I  
         - Note: If you have a command in the last line 36, 
                 you loose this line by inserting a new line!

DELETE : this line by input: D

BACK TO LINE#: You go back to the input mask by input: B


Basics commands in the input mask
LINE#: Input a number from 1 to 36 for the editing line.

E : Start Elmer, who is following your input commands.

NEW - Delete all lines / commands / the program.


Special Key
  • RUN/STOP : If pushing in the drawing mode, the BASIC program "Elmer the turtle" is breaked.


References[edit]

  1. Peter Crosby: "Turtle-Tutor for Tykes", RUN magazine September 1986, p. 46-48 (description), p. 98-100 (listing)

Links[edit]