10 ESC$ = CHR$(27) - Page 108

CHAPTER 2 PCL - 88 

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See the following example for programming examples using gray scales. 

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>