1000 rem LOW RES PLOT DEMO #1
1010 rem D.M.BROAD. 19/2/89.
1020 :
1030 trap 1400
1040 PL=dec("1010")   :rem SYS ADDR
1050 :
1060 sys PL,11,  0,0  :rem SCREEN
1070 sys PL, 0        :rem INITGR
1080 sys PL, 3,113,0,0:rem SELWIN
1090 sys PL, 5        :rem CLEARW
1100 sys PL, 7,  3,3  :rem MOVETO
1110 sys PL,15, 76,46 :rem BOX
1120 :
1130 do
1140 :TX=10*rnd(1)+4: TY= 6*rnd(1)+4
1150 :TX=TX and 254 : TY=TY and 254
1160 :BX=80-TX      : BY=50-TY
1170 :MX=BX-TX      : MY=BY-TY
1180 :
1190 :rem DEFINE WINDOW
1200 :sys PL,7,TX,TY  :rem MOVETO
1210 :sys PL,2,BX,BY,1:rem SETWIN
1220 :sys PL,3, 2,64,1:rem SELWIN
1230 :
1240 :A%=rnd(1)*3+1:B%=rnd(1)*3+1
1250 :C%=rnd(1)*3-3:D%=rnd(1)*3-3
1260 :
1270 :for Z=0 to 1
1280 : A=0: B=0: C=MX-1: D=MY-1
1290 : do
1300 :  rem COLOUR
1310 :  sys PL,16, (rnd(1)*128)or 33
1320 :  sys PL, 7, A,B:rem MOVETO
1330 :  sys PL,15, C,D:rem BOX
1340 :  A=A+A%:B=B+B%:C=C+C%:D=D+D%
1350 : loop until C<0 or D<0
1360 :next Z
1370 :sys PL,21, 0    :rem INVERN
1380 loop
1390 :
1400 print chr$(147)chr$(5):end