Systems Reference Library - All about the IBM 1130 Computing ...

IBM 1627 PlotterThe IBM 1627 Plotter (Figure 78) provides anexceptionally versatile, reliable, and easy-to-operateplotting system for the 1800 system. The plotterconverts tabulated digital information into graphicform. Bar charts, flow charts, organization charts,engineering drawings, and maps are among the manygraphic forms of data which can be plotted on the1627 Plotter. One 1627 (model 1 or 2) can beattached to the system.FUNCTIONAL DESCRIPTIONThe 1627 operates under direct program control.Data is transferred serially from core storage to the1627, where it is translated into actuating signals.These signals produce drawing movements on the1627.Actual recording is produced by incrementalmovement of the pen on the paper surface (y-axis)and/or incremental movement of the paper under thepen (x-axis). The pen is mounted in a carriage thattravels horizontally across the paper. Vertical plottingmotion is achieved by rotation of the pin-feeddrum, which also serves as a platen (Figure 79).The drum and pen carriage are bidirectional;that is, the paper moves up or down, and the penmoves right or left. Control is also provided toraise the pen from or lower the pen to the paper surface.The pen remains in the raised or loweredposition until directed to change to the oppositestatus.The drum and pen-carriage movements and penstatus are controlled by digits transferred to the 1627.Bit positions 0 through 5 of each output word are decodedinto directional signals which cause a 1/100-inch incremental movement of the pen carriage and/or paper, or a raise-pen or lower-pen movement.The relationship of bit positions 0 through 5 of theoutput word and pen or paper movement is as follows:Bit Position Movement0 Pen down1 Drum down2 Drum up3 Carriage right4 Carriage left5 Pen upFigure 80 shows possible motion resulting fromeach word in the output record. It is possible to givecontradictory bit combinations, such as 1 and 2 (drumdown and drum up), or 3 and 4 (carriage right andcarriage left). These are invalid and should not beused. No definite statement can be made about whataction (if any) will occur if opposing movements arespecified.The time required to raise or lower the pen is100 ms. The time to plot a point is approximatelyPlot Chart PaperSupplyPen and Carriage SpoolTake—up Spool,5662 JFigure 78. IBM 1627 PlotterFigure 79. 1627 Paper and Pen MotionsIBM 1627 Plotter 159