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
Sharp Corporation years later, in 1966, Sharp introduced its first IC calculator using 145 Mitsubishi-made bipolar ICs, priced at JP¥350,000 (about US$1000). Its first LSI calculator was introduced in 1969. This was the first pocketable calculator priced at less than JP¥100,000 (less than US$300), and turned out to be a popular item. The company was renamed Sharp Corporation in 1970. Sharp produced the first LCD calculator in 1973. Sharp had a working relationship with Nintendo during the 1980s, and was granted licensing rights for the manufacture and development of the C1 NES TV (1983, later released in North America as the Sharp