Abstract: A small-sized and light weight printer which can suitably be incorporated in a desk-top calculator or the like. The printer has a simplified mechanisms for driving of a printing head, a paper feed and a printing control, and can operate stably with a reduced power consumption.

Abstract: A typewriter having a carriage return line indexing key to initiate in parallel a powered carriage return and a powered line indexing operation is provided with linkage associated with the carriage return action which assures initiation of the line indexing operation should the keylever depression be sufficient to initiate a carriage return operation but insufficient to initiate the line index operation.

Abstract: In a print head assembly for calculators and the like, the print head is reversibly driven in a print and return direction transversely of the direction of advancement of the recording medium by a drum segment having a cam drive in the form of an endless helical groove which extends along a cylindrical surface of revolution between opposite ends of a drive axle mounted in driving relation to the print head so that rotation of the drum will impart translational movement to the print head through a suitable drive member engaged by the helical groove at a preselected rate of speed both in the print and return direction.