The SPG 422 is a component digital sync pulse generator (SPG). The SPG 422 provides basic setup and timing signals for component digital tape recorders and processing equipment systems. It provides audio tones and a few simple video test signals needed to adjust equipment and stripe video tapes. Analog black signals are the timing reference signals of choice and the SPG 422 provides six analog black signals each with separate timing controls. Because the SPG 422 has good frequency stability, it can perform as a stand-alone generator or genlock to an external PAL or NTSC signal. Some installations use 525/59.94 and 625/50 component signals simultaneously or switch between standards regularly. Dual-standard operation is possible with the SPG 422 architecture. Also important for dual-standard operation, is the ability of the SPG 422 to output audio tones locked to the video standard(s) in use.