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
Texas Instruments Compact Computer 40 the keyboard is vile". It also noted the lack of any external storage because the TI wafertape drive was not available, and the complete lack of software. The review suggested that the computer should be considered a "dandy scientific calculator" since good programmable calculators cost about the same as the CC-40's $250 price, but that otherwise "virtually all of its competition vastly outstrips it in power and features", including the $99 TI 99/4A. Texas Instruments Compact Computer 40 The Texas Instruments Compact Computer 40 or CC-40 is a battery-operated portable computer that was manufactured and released by Texas Instruments in