Abstract: An operator panel for printers which includes visible function indicators as well as trigger elements for controlling printer functions has a single function operating and indicating field arranged in a matrix fashion with lines and columns wherein the lines indicate classes of functions and wherein a particular column includes designations as well as indications for the classes of functions; there is at the most one indication and/or one designation in any matrix intersection, a single key is associated with each of the columns; a second panel field is disposed alongside the first one, having a single operating key, and being individually organized commensurate with the lines and in a single column but being independent from said designations of the particular column.

Abstract: A matrix printer, having a movable print head, a paper feed and advance mechanism and an ink ribbon system, is driven by two motors; one for the print head and one for paper feeding and ribbon movement. This second motor is a reversible one and drives the paper advance when rotating in one direction and the ink ribbon when rotating in the opposite direction. Speed control for the paper feed phase is derived from a cam on the input shaft for the paper advance. A reset mechanism for that shaft is also included.