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Data Flow Structure for High Performance Impact Printers

IP.com Disclosure Number: IPCOM000063315D
Original Publication Date: 1985-Mar-01
Included in the Prior Art Database: 2005-Feb-18

Publishing Venue

IBM

Related People

Authors:
Johnson, RJ Rhodes, JW [+details]

Abstract

Daisywheel printers normally require 2,304 bytes of data storage. Increasingly complex systems sometimes require a reduction of data storage in the controlling processor. The data flow structure distributes the tasks to two segments with balanced loading using a three-level buffering concept to store commands from the host source. Three levels of buffering are used to store printer commands from the host source, as indicated in the figure. The first buffer level 1 is actually a fixed-length entry circular queue able to hold varying command sizes long enough to sustain printer operation during most peak processor loading periods in the host. For velocity computations, the first level buffer must be at least two commands deep. Velocity computations are made when the commands are removed from the circular queue.