Abstract: Apparatus for controlling the advancement of punch cards or like sheet material past a plurality of work stations such as may comprise a data recorder used in the preparation and processing of punch cards. Control means are provided to sense the nature of an operation being performed on a particular card as well as the presence of punch cards at other of the plural work stations comprising the system and in response thereto selectively energize the advancement mechanism such that each punch card processed through the system will be advanced at an optimum rate. In the event no punching or printing operation is to take place on the punch card the speed of the advancement mechanism is increased considerably in excess of that which would otherwise enable the advancement mechanism to be accurately stopped.

Abstract: A programmably alterable incrementing system particularly adapted for use in conjunction with an apparatus for selectively indexing punch cards or like sheet material through a work station; such apparatus being particularly susceptible to errors in tolerance such as may be due to inaccuracies in mechanical components, but which are particularly attributable to variation in humidity conditions. Means including a stepping switch are provided to introduce a corrective factor, as needed, into the indexing system to ensure that the required correspondence exists between the actual and the intended increment imparted to a punch card as it is advanced through the work station.