10 screen 8,0:set page 1,1
20 bload"picture.sr8",s:set page 0
30 zf=1:al=0.2:zs=0.2 		REM Zoomfactor and rotation angle
40 co=cos(al):si=sin(al):	REM on time (co)sinus calculation for current frame
50 x=-50:y=-50			REM coordinates of upper left corner
60 xc=(x*co+y*si)*zf+128		
70 yc=(y*co-x*si)*zf+106	REM XC,YC the coordinates in original picture
80 REM Calculating step (0,1)
90 xv=(si)*zf+128		
100 yv=(co)*zf+106	REM XC,YC the coordinates in original picture
110 REM Calculating step (1,0)
120 xh=(co)*zf		
130 yh=(-si)*zf	REM XC,YC the coordinates in original picture
140 REM getting trough the picture
150 for i=0to100
160 x=xc:y=yc
170 xc=xc+xv:yc=yc+yv	REM XC,YC placed one step vertical step lower
180 for j=0to100
190 setpage,1:c=point(x,y)
200 x=x+xh:y=y+yh
210 setpage,0:pset(j,i),c
220 next j,i
230 al=al+0.01
240 zf=zf+zs:if ((zf=1) or(zf=5)) then zs=-zs
250 goto 40