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
Delta Electric Company Delta Electric Company The Delta Electric Company was an American electronics manufacturer formed in 1913 in Marion, Indiana that produced lanterns, flashlights, automotive and bicycle lighting, battery tubes, horns, horn buttons, light switches, other battery-powered electrical parts, and bilge pumps. It was moved to Marion from an existing business in Chicago following a stock purchase. Delta was purchased in 1964 or 1965 by the Novo Industrial Corporation. One of Novo Industrial Corp.'s subsidiary companies, King Bee Manufacturing Co., was moved to Marion, and its line of automotive lighting and safety equipment, including headlamps, safety lights, directional lights, mirrors, and reflectors