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
Union Electric Company primarily in Missouri, where more than half of its customers reside in the St. Louis metropolitan area. It also serves adjoining parts of Illinois, and formerly served Iowa as well through the mid-1990s. Union Electric Company The Union Electric Company of Missouri (formerly ) was an electric power utility that was organized in 1902 and grew to be one of the S&P 500 largest companies in the United States. In 1997, its holding company merged with a smaller neighboring utility, Central Illinois Public Service Company through its holding company, CIPSCO Inc. (formerly ), to form Ameren Corporation () based in