Sony's D1 format was the first major professional digital video format, introduced in 1987.
D1 stored uncompressed digitized component video, encoded at YUV 4:2:2 using the CCIR 601 raster format, along with PCM audio tracks as well as timecode on a 19mm (3/4") cassette tape. Uncompressed component video uses enormous bandwidth, and a simpler D2 system soon followed.
D1 was notoriously expensive and the equipment required very large infrastructure changes in facilities which upgraded to this format. Early D1 operations were plagued with difficulties, though the format quickly stabilized and was renowned for its superlative image quality.
D1 is still in some usage as of 2003, and many of the technologies introduced with this format are still common to more recent digital videotape formats.
Panasonic's D5 format has similar specifications, but was introduced much later.