International Business Machines Corporation

Lee T Zimmerman

Ludwig R Siegl

Charles J Weber

Delbert C Thomas, Jr

Gregory N Baker

Gary T Bare

Willard B Greene

A printer subsystem receives command and data information from a host system and retains a large number of font images in an associated storage area within the printer subsystem. A base font image set is ordinarily selected by the user but provision is made to dynamically change the font images as may be required in a real time fashion during actual printing operations. The font images are stored in a compressed form in the storage area. Routines involve use of pointer tables and data tables. It is possible to select an entire set of new font images in place of the base set of images or to modify only selected character images within the base font image set.

Font selection and compression for printer subsystem

A printer is provided with facilities for increasing the printing throughput. This involves a partial line turnaround operation. The printer has means to move a form or document past a print line, a ribbon drive assembly, and a print assembly incorporating a plurality of print wires arranged in print head groups, each group comprising a predetermined number of print wires. If, as an example, the print assembly has two, four, six, or eight print heads, each can accommodate eight wires in the embodiment described. The print wires are arranged in a slanted serrated pattern and provision is made herein to insure that the print heads move at least far enough to print their assigned character locations prior to the performance of any turnaround in individual lines being printed. Routine involves the accessing of tables stored in conjunction with a microprocessor, the tables indicating the optimum turnaround situations for the different print head configurations. In addition, an emitter is provided in the printer unit which has character emitters, margin emitters and other emitters as well as turnaround emitters that are used in conjunction with the turnaround decision making process to reverse direction of the print head assembly in order to start printing of a new line.

Partial line turnaround for printers

A diagnostic routine is provided for a printer or printer subsystem having a plurality of print wires and print heads arranged in a nonconventional wire image pattern, the diagnostic routine providing a printout of wire firing and misfiring to quickly and accurately indicate the condition of the wires, wire actuators, and other components.

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Boca Raton, FL, United States of America

Lee T Zimmerman