mlsmith@nadc.ARPA (09/25/84)
There are all sorts of tape streamers which are generally used for backup. Tape cassettes of the Phillips, Kennedy, and other proprietary types are most popular. Higher densities are available on rotating head recorders. These are based on video helical scan and quadrature (90 degrees from scanning direction to tape movement direction) scan. Laser disk and Electron beam memory systems are at the laboratory stage.