Rotary-head Digital Audio Tape: A standard for digital audio tape recording which employs a rotating head mechanism similar to that of video recorders. Two channels of 16-bit digital audio information, plus subcode and track information, can be recorded onto a tape ap-proximately 3mm wide, traveling at a very low speed of about 50 cpm. The tape is housed in a case similar to a video cassette, though much smaller. R-DAT machines offer three sampling rates: 32kHz, 44.1kHz, and 48kHz. Maximum continuous record time for a cassette is two hours at standard play and four hours at long play, with reduced quality. See also DAT.