Abstract: In the printer pin control circuitry described herein, data bits which request the actuation of respective pins are entered, indirectly, into respective digital equivalent shift registers to provide, for each pin, a respective short term history of actuation requests. A high speed, special purpose digital processor sequentially examines the several shift registers to determine, at successive points in time, whether each pin winding should then be energized or not to produce an effective energizing and damping waveform under a variety of sequential actuation conditions.

Abstract: The printing apparatus disclosed herein generates alphanumeric characters of high quality, using a multi-pin printing head capable of forming discrete dots or pels, by controlling the actuation of the printing head with a timing resolution which is an order of magnitude finer than the nominal dot diameter so that a line smoothness for slanted or curved lines is obtained which is greater than that obtainable by a uniform matrix. The printing head is repeatedly traversed or scanned across the paper to provide essentially parallel lines of scan separated vertically by a distance which is a submultiple of the vertical spacing of the pins so that overlapping dots may be provided in the vertical dimension. By these means the apparatus facilitates the formation of smooth lines of essentially arbitrary slope or curvature.