HP 35s Games and Routines for Input, Sorting, and Randomization

This book introduces the reader to a few, hopefully, fun games in an attempt to demonstrate a variety of programming techniques and features of the HP 35s. Just as important are the approaches to different types of programming problems – problems which challenge both the ‘calculator’ and the programmer. The games include: The H2P2 Fortune Teller – along the lines of the Magic 8-Ball (Carter and Bookman, 1950); the Mini Enigma Encipherment ‘Machine’; the Mini Y ‘Dice’ Game along the lines of Yahtzee (Edwin S. Lowe, 1956); Rock– Paper–Scissors; and Tic-Tac-Toe. All of the games utilize the random number generator of the HP 35s along with various decision and display techniques. The utility programs include those to input data into the indirect storage variables, as well as those to generate, sort, randomize, read, and view data. All of the programs utilize different indexing techniques for the 801 indirect storage variables of the HP 35s. The example programs use a straight forward approach which does not require or rely on sophisticated knowledge of complex calculator intricacies. While the HP 35s has a limited selection of programming commands, with a little creativity, one can simulate more complex commands.One of the attractions of the HP 35s is its ability to use Reverse Polish Notation (RPN) which is used throughout the book. Although it lacks a computer interface and a graphics display, the HP 35s is reasonably priced at about $55 (March 2020). Its greatest strength is perhaps its capacity to store custom programs and equations specific to an individual’s needs.The target audience for this book is the casual or infrequent HP 35s user wishing to expand their knowledge and use of the calculator – however, the book assumes no prior HP 35s experience. Explanations are provided for each command, along with the key locations – of which there are roughly 150 on the keypad. Note: This book does not cover every aspect of the HP 35s. Therefore it is important to have the HP 35s User’s Guide which is available free online.