Digital correlation recorder

TLDR: In this paper, the authors present a correlation recorder where the keying and recording functions are performed by digital circuitry and each function is synchronized to the other by a precision clock generator.

Abstract: Keying and recording functions in a correlation recorder are performed by digital circuitry. Each function is synchronized to the other by a precision clock generator. Among the functions controlled are: keying signals for initiating external events, printing of input signals representing external events, and record transport for proper positioning of the input signal on a permanent record with a precisely known time relationship to the keying signals. The time sequence of keying and recording functions is precisely adjustable over a wide range of settings.