International Business Machines Corporation

Guy D'Hervilly

Armand Brunin

Christian De La Salle

A microprocessor provides to a main instruction source, A FIFO memory, various instructions (paper feed, hammer settings, . . . ) for a printer represented by instruction register thereof. For each instruction of the (A,C) type representing an operation code (C) for instance, a set command) for the hammer with address (A), address (A) is inputted into a secondary instruction source, a FIFO memory, simultaneously with a time information (Y) issued from a cyclic type binary counter. A so called mask bit (Z) which changes of value on every cycle, is also inputted, after complementation with time information (Y). When the contents (Y,Z) of counter and the contents (Y',Z) available from the output of source, are identical, comparator indicates to control unit that address (A') available from the output of source corresponds to the address of an hammer to be reset. Control unit adds code (C=RESET) and provides instruction (A', RESET) to register. Control unit is also provided with various means for controlling the status of instruction sources and manages the priorities when contradictory instruction are received. The system allows the reset commands to be removed from microprocessor and the input/output devices thereof, which saves machine time. In addition, the number of instructions to be stored into source is almost halved.

Printer hammer resetting control system

A method and electronic network for limiting the electrical noise arising during transmission of digital data signals from a first integrated circuit having multiple output devices at which the data signals are formed to the input of a second integrated circuit. The method and network feature steps and means for sensing the conduction state of the first integrated circuit devices and for generating a control signal to invert the data signals before transmission when the number of output devices conducting is equal to or greater than a predetermined number. The method and network also feature steps and means for transmitting the data signals and control signal so that the data signals may be reconstituted to establish the data signals as they appear at the first integrated circuit output, before the data signals are presented to the second integrated circuit input.

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Ris Orangis, France

Guy D'Hervilly