About the Editor David Ahl has a BEE from Cornell University, MBA from Carnegie-Mellon University and has done further work in educational psychology at the University of Pittsburgh. Two years in the Army Security Agency were followed by four years with Management Science Associates working on computer models and analysis of new consumer products. He continued work in computer analysis (of vocational education graduates) with Educational Systems Research Institute. He joined Digital Equipment Corporation in early 1970. As Education Product Line Manager he formulated the concept of an educational computer system consisting of hardware, software, and courseware (Edu-System) and helped guide DEC into a leading position in the education market. Mr. Ahl joined AT&T in1974 as Education Marketing Manager and was later promoted to Manager of Marketing Communications where he was responsible for the development of sales promotional strategies and materials for the Bell System. Concurrent with this move, he started Creative Computing as a hobby in late 1974. As Creative Computing grew, Mr. Ahl left AT&T in 1978 to devote full time to it. Creative Computing magazine today is number 1 in software and applications for small computers and a leader in publishing books, cassette and disk software, and related materials. Mr. Ahl is the authorof 10 books and over 70 articles in the use of computers. He is a frequent lecturer and workshop leader at colleges and professional conferences. He is a member of ACM. AEDS, AERA, COSMEP and NCTM. Copyright 1976 by Creative Computing. All rights reserved. No portion of this book may be reproduced-electronically or by any other means, including photocopying-without written permission of the publisher. Library of Congress Number: 76-438 ISBN O-916688-01-1 Printed in the United States of America 10 9 8 7 6 5 Creative Computing Press 39 E. Hanover Ave. Morris Plains, NJ 07950