Abstract: A control system for high speed printers including a low speed microprocessor that processes data input by a one-time serial operation on the data bytes to direct printing operations into a virtual image memory that is a map of the printing sequence for an entire line. A map of the character printing program for each print position is transferred for each character into a print control memory so that printing can proceed as though a large scale high speed computer was in charge of the printing process.

Abstract: A type train assembly includes a pair of parallel belts stretched around drive wheels, a series of type carriers centered between and attached to both belts to balance and divide the traction and tension forces, and a guide bar slidably engaging a groove in the rear surface of each type carrier to guide them accurately and to support them firmly for impact by print hammers. The type carriers abut one another in the direction of travel and this combines with the tension in the belts to reduce dragging of the type, which would otherwise result from stretching of the belts occasioned by hammer impact. The carriers are formed with pairs of transverse arms having flanges and projections for gripping the pair of belts, and with recesses for engaging teeth formed in the belts, to fix the carriers firmly thereon.