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
Plug-in electric vehicles in the United States occupancy. The study concluded that the increased environmental impacts of manufacturing the battery electric technology is more than offset with increased environmental performance during operational life. For the assessment, the study used the average electricity mix of the U.S. grid in 2014. In the 2014 mid-size cars category, the Leaf also ranked as the best all-around performance, best environmental and best social performance. The Ford Focus Electric, within the 2014 compact cars category, ranked as the best all-around performance, best environmental and best social performance. The Tesla Model S ranked as the best environmental performance in the 2014 full-size cars