Added TEKLINES.BAS demo

TEKLINES.BAS

@@ -0,0 +1,19 @@
+10 REM Play with Tektronix graphics
+20 ESC$=CHR$(27)
+30 GS$=CHR$(29)
+40 US$=CHR$(31)
+50 CSI$=ESC$+"["
+60 PRINT CSI$+"?38h"
+70 FOR I = 1 TO 200
+80 X=RND(8)*1024: Y=RND(8)*768: GOSUB 160: C1$=XY$
+90 X=RND(9)*1024: Y=RND(9)*768: GOSUB 160: C2$=XY$
+100 PRINT GS$+C1$+C2$+US$+CHR$(13)
+110 NEXT
+120 REM Pause for a short time
+130 FOR I = 1 TO 10000: NEXT
+140 PRINT CSI$+"?38l"
+150 END
+160 REM calculate coordinates for x,y
+170 REM returns them in xy$
+180 XY$=CHR$((Y\32) OR 32) + CHR$((Y MOD 32) OR 96) + CHR$((X\32) OR 32) + CHR$((X MOD 32) OR 64)
+190 RETURN