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
Yamaha electric guitar models position). The controls were a five position pickup selector and master volume and master tone controls. The bridge was a TRS-Pro locking tremolo. All hardware was gold plated. Finish options were Antique Sunburst, Black Burst, Faded Blue and Violet Burst. YAMAHA began making the RGX 121 S in 2003 The RGX 420 S was introduced in 2003. The Yamaha RGX 420 is an electric guitar that, so far, has been released two times in versions "S" and "dz", featuring different paint-finishes but all the same mechanics and electronics. YAMAHA manufactured the RGX 420 SD6 (Drop 6) between 2001 and 2003