Turtle Home Page

Turtle, a Friendly Introduction to Programming

Welcome to the home page of Turtle, a graphics programming environment designed to provide an enjoyable introduction to programming, together with a practical insight into fundamental concepts of computer science such as compilation and machine code.

Documentation

Full documentation is provided in the comprehensive Help file included in the package. The table of contents is as follows:

Turtle Graphics Programming System
- Introduction
- The Canvas
- The Program
- The Turtle Standalone Run-Time System
- Teaching Aims: Deep Understanding of Programming Concepts
- Current Version of the Turtle Software
- Hardware Requirements and Issues
Menus in the Turtle Graphics System
- File Menu
- Edit Menu
- Layout Menu
- Compile Menu
- Options Menu
- Help Menu
Turtle Graphics Programming
- Programming Quick Reference
- Programming Essentials
- Introduction to Pascal Syntax
- Pascal Syntax Reference
- Procedures and Parameters
- The Recursion Factory
The Visual Compiler and the Turtle Machine
- An Introduction to PCode
- Technical Note on Variables, Procedures, and Parameters
- PCode Reference Guide
Working with the System
- Exercises

Versions, Upgrades, and Feedback

The current distribution is Version 7.00 of the Turtle Graphics software, produced in September 2003; no previous versions are now maintained, though the last distribution of the previous version (Version 6d) is provided here for backward compatibility of PCode files (since the virtual Turtle machine PCode instructions have been extended since Version 7.00). Changes planned for the relatively near future include:

Type-checking for boolean and integer variables.
Introduction of “case” and “while” structures.
Functions.
Various editor improvements (including multiple files).
Extension of the auto-formatter to provide more assistance for error detection.
Possibly string variables.

More ambitious future possibilities include:

User-defined event handling.
Decompilation and the incorporation of alternative program syntaxes (e.g. C and BASIC-style as well as Pascal) with mutual translation.
Full object-orientation with multiple turtles (which would allow also the incorporation of Java syntax).

Any feedback on the system, or suggestions for further improvements that might enhance the power and versatility of the system, especially for an educational context, will be greatly appreciated. Please email Peter Millican.

Downloads

Turtle 7.00

This program is freeware for educational use, but please respect the copyright, and ensure that if you pass it on you do so without charge, make clear its authorship, and leave all documentation intact. The program is provided in two forms, first as a standard ZIP archive, and then as a self-extracting ZIP file:

Turtle version 7.00 as a standard ZIP archive

Turtle version 7.00 as a self-extracting ZIP file

Turtle 6d

Turtle version 6d as a standard ZIP archive

Turtle version 6d as a self-extracting ZIP file