YJ2 has asked for an explanation of theTILES program on issue 22. Here is anattempt to explain the one liner stepby step: Text in RED is taken from the actualprogram. MODE1:CLG Selects a four colour mode and clears the screen. FORx=20TO1230STEP62 This is the outer loop which prints the columns across the screen from left to right. FORy=20TO900STEP62 This is the inner loop which prints each individual column from bottom to top. This next section is responsible forprinting a single tile by drawing awhite box and filling it: GCOL0,3 Select graphic colour white. MOVEx,y DRAWx,y+50 DRAWx+50,y+50 DRAWx+50,y DRAWx,y Draw the box. GCOLRND(8)*RND(8),RND(4) Select a graphic colour at random. PLOT133,x+10,y+10 Plot 133 flood fills from point X,Y until non background is found. Therefore, if point X,Y lies inside a box, the box will be filled. NEXT End of column. NEXT End of screen.