EachFX-850emulationgraphicscommandyou senddoesthreethings:it
turnsonthegraphicsmode,specifieshorizontaldensity,andsayshowmany
columnswidethe cominggraphicsdatawillbe.
Graphicscommandsallprintatthesameverticaldensityor“resolution”—
72dotsperverticalinch.Thecommandsalllookthesame;wheretheydiffer
is in horizontaldensity.
Here’ske commandfor the60 dots-per-inchdensity:
<ESC>K nl n2
The n2 is thenumberof 256-columngroups(eitherO,1or 2). And the n]
representsunits,thenumberof leftovercolumns.
So to printjust 150columnsof graphics,youwouldsendthiscommand:
<ESC>K 1500
Thattranslatesto 150+ (Ox 256)= 150columns.
Buttoprint260columnsofgraphicsatthesamedensity,youwouldsendthis
command:
<ESC>K 4 1
Thisonetranslatesto 4 + (1 x 256)= 260 columns.
Rememberto put exactlythe
rightnumberof columnsin yourcommand.
Otherwiseyou’ll inadvertentlyuse text as graphicsdata, or vice versa.
Anotherhint:inBASIC,theWIDTHstatementcanhelpyoukeepunwanted
carnage returnsfrom messingup your graphics.
5.6.3 Othergraphicsdensities
Let’ssummarize:Whenprogramminggraphics,youfirstsetthelinespacing
toproducetheeffectyouwant(typicallyat7/72or8/72inch).Thenyousend
yourgraphicscommandand data.Finally,you resetline spacingand any
othertext settingsas needed.
How do text settingsaffectgraphics?Neitherextendedprintnor double-
stnkeboldworkin graphicsmode.The<DEL>commanddoesn’tworkin
graphicseither.And if you’reusing“mostsignificantbit”settingsfor an
olderkind of computer,graphicsmodeignoresthem.
OK,let’s havea lookat graphicscommandsfordifferentdensities.
114
