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
Crescent Electric Supply Co. Crescent Electric Supply Co. Crescent Electric Supply Company is an American electrical hardware supplier. It was founded in 1919 in Dubuque, Iowa, but is currently headquartered in East Dubuque, Illinois. One of the largest companies of its kind, Crescent Electric Supply was ranked by "Forbes" as the 435th largest privately held company in the United States in 2008. Electric contractor Titus B. Schmid founded Crescent Electric Supply in Dubuque, Iowa, in April 1919. Schmid believed that he could deliver goods through the river from St. Louis or Minneapolis to Dubuque faster then existing electronics manufacturers. A 1957 article in "BusinessWeek"