Abstract: A general-purpose oscilloscope system is disclosed wherein waveforms acquired by the vertical and horizontal preamplifier channels can be displayed immediately, or they can be digitized and stored in a memory from where they can be recalled, reconstituted in their analog form and displayed at a later time. The processing system permits simultaneous display of instantaneous and processed waveforms, and includes facilities for processing associated z-axis signals and readout data as well. Access to peripheral equipment, such as a computer or the like, permits the digitized waveforms to be mathematically manipulated and returned to the memory in the processing system for ultimate display. The oscilloscope system can be assembled in a modular manner, whereby the processing unit becomes an integral part of the instrument, or the system can be assembled as a general-purpose oscilloscope without the processing unit, allowing a user to add the processing capability to his system at a later time.