1982

Sony's original DAT prototype, still tagged PCM Tape Recorder.
CD's 1982 buzz oblige, the sampling frequency of this proto was 44.1kHz ; 48kHz would be set in the white papers in 1984. The full tag of this proto, btw, was "Rotary Head Ultra High Density Digital Audio Recorder".

S-DAT (Stationary Head) still was a runner up in '82 but R-DAT (Rotary Head) finally won ; the S-DAT specs would find their way into the professional DASH format or even... Philips' DCC :)