The HP 1651A is a 32-channel STATE/TIMING logic analyzer, selectable in 16 channel groupings. The user interface consists of a panel keyboard with an RPG knob and a nine-inch whit phosphor, high resolution CRT for information display. A 3 1/2 inch Sony disc drive, for setup storage and retrieval, is integral to the analyzer. An RS-232-C port and external scope trigger are available on the rear panel. The RS-232-C port is used for printer hardcopy output or for analyzer control via a controller.