| NAB National Association of Broadcasters. NOISE Random electrical energy or interference. In video, noise can produce a random salt-and-pepper pattern over the picture. Heavy video noise is called snow. Non-intra coding Coding of a macroblock (or picture) that uses information from both that macroblock and from macroblocks occurring at other times. NTSC National Television Systems Committee of the Electronics Industries Association (EAI) which prepared the NTSC format specifications approved by the Federal Communications Commission, in December 1953, for US commercial color broadcasting. NTSC format A color television format having 525 scan lines, a field frequency of 60 Hz, a broadcast bandwidth of 4 MHz, line frequency of 15.75 KHz, frame frequency of 1/30 of a second, and a color subcarrier frequency of 3.58 MHz. NTSC uses YIQ. See also PAL, SECAM. NUBUS The expansion bus for versions of the Macintosh computers starting with the Macintosh II and ending with the Performa. Current Macs use the PCI bus. N ull ModemA specially designed cable that allows you to connect two computers directly to each other via their communications ports (RS-232 ports). Null modems are particularly useful with portable computers because they enable the portable computer to exchange data with a larger system |
