Looking at Books
Reviewed by Robert K. Kawaratani
by David D. Thornburg
Published by Addison-Wesley Publishing Co.
Picture This! is the tutorial introduction to Turtle Graphics that Atari should have included with its Pilot package. This should not be taken as a criticism of the documentation that is included with Pilot, which is excellent. Picture This! is simply one of the best tutorial packages written for the beginner that I have had the pleasure of reading. The mathematical and the string handling commands are covered in this book only as they are relevant to graphics. The sound command is not covered at all, which may be a disappointment to some, but is appropriate because this is a book on the use of Turtle Graphics. Those topics appropriate to growth as a "Friend of the Turtle" are covered. The other capabilities of Pilot with the exception of the interface to machine language are adequately covered in Student Pilot and Pilot Primer.
David Thornburg leads the reader on a gentle tour of the capabilities of Atari Pilot Turtle Graphics. The tour begins with an in-depth lesson entitled "Let's Draw a Square" where the Gr: (Graphics), TURN, and DRAW commands are introduced. Subsequent chapters explore the use of the J: (Jump), REN: (Renumber), T: (Type), A: (Accept), U: (Use), New, VNEW, PA (Pause), and C: (Compute) commands as they are relevant to the use of the graphics capability of Pilot.
As part of the hands on approach used throughout the book, the author allows the user to make a variety of mistakes as drawing lines that are too long or nesting modules too deeply. He then guides the user through corrections for the mistakes or explains why an error message has been provided.
One of the great strengths of Pilot as a programming language is the modularity of the language. The beginner learns a more structured approach to programming than with BASIC. Thornburg provides a strong introduction to the use of modules in Pilot programming. One demonstration that he provides of the power of modules in Pilot is a simple example of animation.
The book is spiral bound for convenience in use with the computer (after all this is a learn by doing book). All of the modules used in the book are conveniently listed in an appendix. The index is well organized and clearly differentiates between commands, modules, and other topics.
Picture This! is really a necessity for the beginning Pilot user. It will quickly introduce all the essentials for using the Turtle Graphics capabilities of Pilot. Although an experienced ATARI user would probably be able to learn the essentials of Pilot from Student Pilot, Picture This! provides a more systematic approach to learning how to use the powerful Turtle Graphics capabilities of Atari Pilot than the documentation provided by Atari.