A Pair of Program - Compatible Personal Programmable Calculators

One is a small, portable printing calculator and the other is a hand-held version without a printer. Both versions feature a "smart" magnetic card reader, and each can run the other's programs. TWO POWERFUL NEW fully programmable per sonal calculators in the tradition of the HP-65 (the first fully programmable pocket-sized scientific calculator)1 are the pocket-sized HP-67, Fig. 1, and the HP-97, Fig. 2, a briefcase-portable calculator that has a built-in thermal printer, a buffered keyboard, and a large easy-to-read display. Both new calculators can read and record programs on magnetic cards using their built-in firmware-controlled magnetic card reader/recorders. A novel feature of these two new calculators is that they have exactly the same programmable instruction set. Even the instructions that are used to control the thermal printer on the HP-97 can be programmed on the HP-67 and are interpreted as meaningful display commands when executed by the HP-67. Programs stored on magnetic cards are written in a code that can be properly interpreted by either an HP-67 or an HP-97. Programs written on either machine can be run on the other with appropriate key codes dis played (see Fig. 3). Design Philosophy The basic design goal of the HP-67 and HP-97 de velopment was to provide moderately priced comput ing tools capable of easily solving real-world prob lems. To achieve this goal, previous HP calculators were analyzed for possible improvement. The suc cessful HP-65 contained many innovative features, including its magnetic card reader. Other features that have been well received by users include fully merged key codes, engineering notation, and a pause function. A selection of the best features of the HP calculator line can be found in the instruction set of the HP-67 and HP-97. Speed and memory capacity were also considered during the design of the HP-67 and HP-97. Portable operation was desired, so battery capacity placed a major limitation on speed. After several alternatives were considered, the low-cost, moderate-speed micro processor used in the HP-91 and the HP-21/22/25 series2 was chosen; it yields a system speed roughly equivalent to that of the HP-65. After examination of hundreds of HP-65 application programs it was decided that data memory should be easy to address and efficient to use, since 17. 3% of the operations in a typical program were found to be data Cover: The HP-97 and the HP-67 are fully programmable portable calculators that can run each …