This collection of papers is the result of a desire to make available reprints of articles on digital signal processing for use in a graduate course offered at MIT. The primary objective was to present reprints in an easily accessible form. At the same time, it appeared that this collection might be useful for a wider audience, and consequently it was decided to reproduce the articles (originally published between 1965 and 1969) in book form.The literature in this area is extensive, as evidenced by the bibliography included at the end of this collection. The articles were selected and the introduction prepared by the editor in collaboration with Bernard Gold and Charles M. Rader.The collection of articles divides roughly into four major categories: z-transform theory and digital filter design, the effects of finite word length, the fast Fourier transform and spectral analysis, and hardware considerations in the implementation of digital filters.