Designed to speed you through challenging calculations. grips in the sides of the case promote sure handling. The calculator is powered by one lithium battery (included) that provides approximately 1,500 hours of operation that's roughly four years of normal use. TI's APD" automatic power down feature extends battery life by turning off the calculator after several minutes of non-use. The TI-68 includes a 180-page guide- book that fully describes each function and presents step-by-step examples. A quick reference card provides a handy summary of functions. The TI-68 measures 6.0 x 3.0 x 0.6 inches (15.2 x 7.6 x 1.5 centimeters) and weighs 4.5 ounces (128 grams). TI conducted extensive research among technical professionals, univer- sity professors and engineering students during the development of the TI-68. Surveys of 3,000 individuals and per- sonal interviews with 150 more provided an invaluable understanding of the needs and preferences of these power users. Defining the functions and operating characteristics of an advanced scientific calculator is a lengthy process. In its research TI employed software based on artificial-intelligence principles. This state-of-the-art technique can be used to determine the combination of attrib- utes a product must have to appeal to a specific market segment. With its sleek, ergonomic design, the TI-68 has the look of a powerful problem-solving tool. The easy-to-read liquid-crystal display (LCD) is recessed and tilted to reduce glare. Each character is presented in a 5 x 7 dot matrix. The display shows up to 12 alphanumeric characters; you can scroll to show equations up to 80 characters long. The calculator has 44 keys including 2nd and 3rd function keys, ALPHA, ALPHA LOCK and a large EQUALS key. Keys are color-coded and grouped by function; designations are easy-to- read. Operations found to be used most frequently are assigned to first- function keys. A sturdy sliding cover protects the display and keyboard from dirt and scratches. The cover, which stores securely on the back of the calculator during use, has non-skid feet. A thumb notch on the cover and recessed finger 3