Foreground p.66 THE STANDARD DATA ENCRYPTION ALGORITHM, Part 1: An Overview [author Robert V Meushaw] A detailed description of a "trap door" algorithm p.94 DESIGNING WITH DOUBLE SIDED PRINTED CIRCUIT BOARDS [author David Lamkins] This do-it-yourself technique can save you space p.114 DESIGNING A ROBOT FROM NATURE, Part 2: Constructing the Eye [author Andrew Filo] Design details of the robot's eye in the second of this 2 part article p.142 A STEPPING MOTOR PRIMER, PART 2 [author Paul Giacomo] Interfacing to your computer, and other considerations p.150 BUILD A COMPUTER CONTROLLED SECURITY SYSTEM FOR YOUR HOME, Part 3 [author Steve Ciarcia] Ultrasonics, infrared beams and other exotic ways to make your home secure p.196 THE POWER OF THE HP-67 PROGRAMMABLE CALCULATOR, Part 1 [author Robert C Arp Jr] Learn to use one of the most powerful programmables Background p.12 BUILDING THE HEATH H8 COMPUTER [author Dr Paul R Poduska] A review of a popular computer kit p.14 A MAP OF THE TMS-9900 INSTRUCTION SPACE [author Henry Melton] Organizing one's approach to a machine with 215.95 legal instructions p.32 FILES ON PARADE, Part 2: Using Files [author Mark Klein] File protection systems and sun…