Programmable calculator to use magnetic strips were the HP-41C and TI-59. Continuous memory does not lose its content when the calculator is switched off. With continuous memory the user can, for example, change batteries without losing the entered programs. Compact Cassettes offered a simple, inexpensive alternative to magnetic cards. Usually, an interface module, such as the Casio FA-1, was used to connect the calculator to an ordinary cassette recorder and digital data were encoded as frequency-shift keyed audio signals. Sharp and Hewlett-Packard also sold dedicated micro- or mini-cassette recorders that connected directly to the calculator. These set-ups, while being more practical and
Sumlock ANITA calculator of the directors of Control Systems Ltd., of which the Bell Punch Company was then a subsidiary. Some years earlier, while researching the introduction to his dissertation, he was looking at the mechanical calculators in the Science Museum, London, United Kingdom, and had realised that the future of calculators lay in electronics. Unfortunately, the major mechanical calculator manufacturers were far away in the U.S. and Germany, and Kitz's idea lay dormant until he raised it at that meeting. The directors were very forward looking and were impressed by Kitz and his idea. They decided to open an Electronics Development Department,