10 ESC$ = CHR$(27) - Page 97

2001/10/02 

CHAPTER 2 "PCL" - 77 

Gray scale example 

10 ESC$ = CHR$(27)  

20 WIDTH "LPT1:", 255  

30 REM --- DRAW A PATTERN USING 64 GRAY SCALES ---  

40 X = 50: Y = 100: XL=50 :YL=200  

50 FOR GRAY = 0 TO 100 STEP 2  

60 GOSUB 220  

70 X=GRAY*10+50 :XL=X-XL  

80 GOSUB 260  

90 XL=X  

100 NEXT GRAY  

110 REM --- DRAW A PATTERN USING 8 GRAY SCALES ---  

120 Y=400  

130 FOR GRAY = 0 TO 100 STEP 2  

140 GOSUB 220  

150 X=GRAY*10+50 :XL=X-XL  

160 GOSUB 320  

170 XL=X  

180 NEXT GRAY  

190 REM --- PAPER EJECT ---  

200 LPRINT CHR$(12)  

210 END  

220 REM --- SET THE CURSOR POSITION ---  

230 LPRINT ESC$; "*p"; X; "X";  

240 LPRINT ESC$; "*p"; Y; "Y";  

250 RETURN  

260 REM --- PRINT 64-GRAY SCALE PATTERN ---  

270 LPRINT ESC$; "*c"; XL; "A";  

280 LPRINT ESC$; "*c"; YL; "B";  

290 LPRINT ESC$; "*c"; GRAY; "G";  

300 LPRINT ESC$; "*c130P";  

310 RETURN  

320 REM --- PRINT 8-GRAY SCALE PATTERN ---  

330 LPRINT ESC$; "*c"; XL; "A";  

340 LPRINT ESC$; "*c"; YL; "B";  

350 LPRINT ESC$; "*c"; GRAY; "G";  

360 LPRINT ESC$; "*c2P";  

370 RETURN 

<Sample file 7>