Memory Usage

It is difficult to calculate the amount of Printer memory needed to plot a drawing of any given file size￿ Memory is used￿ not just to hold the input data￿ but also for system overhead￿ processing work/space￿ and storage of the internal representation of the plot￿ Some types of graphics require relatively large amounts of memory￿ Examples are wide lines￿ raster fill patterns￿ polygons￿ and user/defined lines￿

￿lot Orient￿tion

The output orientation of the drawing also has an impact on memory usage￿ Compare a plot of horizontal lines with one of vertical lines￿ Lines plotted parallel to the carriage axis take up considerably less memory than those plotted perpendicular to it￿ The Printer builds graphic display objects on a swath/by/swath basis￿ A horizontal line can be contained in one swath￿ A vertical line spans many swaths and therefore requires more entries in the Printer￿s internal display list￿

￿￿ster Im￿ge ￿rocessor

The raster transfer language ￿RTL￿ provides a solution to insufficient memory on the Printer￿ When all the data is sent to the Printer in the order left/to/right and top/to/bottom￿ the Printer is able to plot the data as it receives it￿ For this to happen￿ software ￿a raster/image processor￿ in the computer must first rasterize all the data￿ The software issues a command ￿referred to in RTL as no neg￿ti￿e motion￿ telling the Printer that it will not receive data for any media location on which it has already plotted￿

The use of no negative motion is called flow mo￿e￿ Data flows through the Printer without being stored in a display list￿ so the size of the file that you can send is almost unlimited￿

Functional Overview

HP DesignJet 430, 450C and 455CA Printers

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