Data sequence display system and time-compression system therefor

Abstract

A system for the cyclical time-compression of a signal waveform, particularly applicable to displays. Continuous input data is temporarily stored, as in a recirculating memory, during the trace and retrace phases (B & A) of a processing or display operation. The stored data is subsequently read out in time-compressed form during the trace phase (B) of the cycle. The average rate at which data is read out of storage is faster than the average rate at which it is entered, the ratio of average readout rate to average entry rate being the compression ratio of the system and corresponding herein with the ratio of a full display sweep cycle to the trace portion of that cycle such that the initial waveform, time-compressed, is displayed in its entirety. In an illustrated embodiment, the data is entered into a recirculating memory at a rate resulting in apparent precession of the data in memory. When the memory is 'full', data is read out at a rate, here syncopated, which on average is faster than the rate at which it enters. In this embodiment, the time-compression ratio is essentially n+1/n, where n is an integer representative of the length of the trace phase of a trace-retrace display cycle. The data samples read out of memory at a syncopated rate are retimed to avoid distortion in the output waveform.