stages, finished episodes of South Park were hastily recorded to D-2 to be sent to Comedy Central for airing in just a few days' time. D-2 replaced Type C videotape for the mastering of LaserDiscs in the late 1980s. D-2 was in widespread use for some ten years, as the computer-based video server (with fewer moving parts and correspondingly greater reliability) became available not long after its release. By 2003, only a handful of broadcasters continued to use the D-2 format, and even then only to access materials recorded on the format. Panasonic introduced D-3 in 1991; it is very similar to D-2 as it uses a smaller cassette case. Format Description General: Format name: D2 digital SMPTE type: D2 Format type: digital composite Scanning system: multi head segmented helical Year introduced: 1989 Developer: Ampex/Sony Physical Data: Tape width: 19 mm Tape speed(s): 5.19 ips Tape thickness: .55 mils Playing time(s): 32, 94, 208 minutes (Small, Medium, Large cassette sizes) Headwheel diameter: 2.95" Speed: 5400 rpm Head-to-tape writing speed: 1078 in/sec. Sampling rate: 4fsc (14.31818 MHz for NTSC) No. of bits: 8 Data rate: 60.1 MB/sec (480.8Mbps) Audio: No. of digital channels: 4 Sampling rate: 48 kHz No. of bits: 20 Models Ampex VPR-200, VPR-250, VPR-300 ACR-225 Commercial Spot Player (robotic tape system) Sony DVR-10, DVR-18, DVR-20, DVR-28 DCR-10, DCR-18, DCR-20, DCR-28 (sold by BTS) DVC 80, DVC 1000s LMS (Library Management System) See also DVCAM DVCPRO D-1 (Sony) D-3 (video) D5 HD D6 HDTV VTR References External links allmobilevideo.com: D2 Specs Google Books: The History of Television, 1942 to 2000 By Albert Abramson Google Books: The Art of Digital Video, by John Watkinson lionlamb.us: Ampex Digital VTR Catalog lionlamb.us: Ampex ACR-225 tech-notes.tv: Ampex history ampex.com: Ampex history D-1, D-2 & D-3: histories of digital video tape Video storage Composite video formats