Mavica (Magnetic Video Camera) is a discontinued brand of Sony cameras which use removable disks as the main recording medium. On August 25th 1981, Sony unveiled a prototype of the Sony Mavica as the world's first electronic still video camera. As with all Mavica cameras until the early 1990s (including later models sold commercially) this first model was not digital. Its CCD sensor produced an analog video signal in the NTSC format at a resolution of pixels. Mavipak 2.0" disks (later adopted industry-wide as the Video Floppy and labelled "VF") were used to write 50 still frames onto tracks on disk. The pictures could be shown on a television screen, using a "special playback viewer unit" plugged into the television set. During the late 1990s and early 2000s, Sony reused the Mavica name for a number of digital (rather than analog) cameras that used standard 3.5" floppy disk or 8 cm CD-R media for storage. Original analog Mavica models The initial prototype demonstrated in 1981 supported video capture at ten pictures per second, and hopes were expressed that this could be increased to sixty pictures per second before the product was launched. Despite the lower image quality compared to traditional film, Japanese news professionals had reportedly been "plaguing the firm with requests for the camera" according to Sony, anticipating the potential convenience of handling pictures in a form that would be readily compatible with computing and telecommunications devices. Sony also demonstrated a thermal transfer printer called the Mavigraph, employing cyan, magenta, yellow and black dye-transfer sheets and capable of producing prints of up to on A5 paper, made up of the 480 lines from the captured images, in a five-minute process. The unreleased original MAVICA as well as the later ProMavica MVC-5000 and MVC-7000 were designed as single-lens reflex systems with interchangeable lenses. At least the ProMavica MVC-7000 also featured lens mount adapters for Nikon and Canon lenses. The VF format soon evolved into the backward-compatible Hi-VF format, supported by the ProMavica MVC-7000 and the Hi-Band Mavica models. Digital Mavica line From the late 1990s on, Sony released a number of cameras based on digital (rather than analog) technology under the "Digital Mavica", "FD Mavica" and "CD Mavica" brands. The earliest of these digital models recorded onto 3.5" 1.4 MiB 2HD floppy disks in computer-readable DOS FAT12 format, a feature that made them very popular in the North American market.