(Digital-1) A 3/4" (19mm) broadcast-quality component digital videotape format that records uncompressed frames in the ITU-R BT.601 standard. Developed by Sony and Bosch in the mid-1980s, D-1 was the first professional digital video format and was later standardized by SMPTE. Using costly tape decks and metal-particle cassettes, D-1 records standard definition (SD) at 704x480 pixels. It takes 1MB of storage for each frame; however, because a small amount of compression takes place, 30 fps requires a transfer rate of only 27MB per second. See ITU-R BT.601, D-2 and SD formats.