1 - Al Kossow's Bitsavers

To illustrate the drawing speed of the 7220, drawing timesfor arc and area fill routines with and without memory refreshwere measured. The 7220 also provides Flash Mode drawingwhere drawing is done during display and retrace. Whilethis yields extremely fast drawing times there is considerabledisturbance to the display when drawing is in progress. Thedrawing time results are shown in Table III.This Application Report has demonstrated how adesigner might incorporate the TMS4416 into a graphicssystem with the 7220. No attempt has been made to detailthe interface or communication between the host processorand the 7220 as so many variants exist (see 7220 DesignManual). The TMS4416 requires minimal circuitry togenerate a dense, low cost, high performance memory arrayfor the 7220.MOS MemoryApplications EngineeringTable III. Drawing TimesRoutine Pixels Drawn Refresh No Refresh Flash ModeArcRadius = 96 69 1,079 p,s 704 p,s 191.8 p,SArea Fillx = 400Y= 200 80,000 926:9 ms 686 ms 227.4 msc.;:;ocaE ..o""" .5enc.;:; oca.!:aQ.•Q.~9-37