PRINT CHR$ 8; OVER 1; "/"

Why do you recover an unblemished B?

2. Type:

   PAPER 0: INK 0
   

   Isn't it just as well that these don't affect the lower part of the screen?
   Now type:

   BORDER 0
   

   and see how well the computer looks after you!
   But what will happen if you do the same after giving:

   LAYER 1,3
   

3. Run this program:

   10  POKE 22527+RND*704, RND*127
   20  GO TO 10
   

   Never mind how this works; it is changing the colours of squares on the screen and the RNDs should ensure that this happens randomly. The diagonal stripes that you eventually see are a manifestation of the hidden pattern in RND – the pattern that makes it pseudorandom instead of truly random.

4. Type in the chess piece characters in Chapter 13 and then type in this program which draws a diagram of chess positions using them:

   5  REM draw blank board
   10 bb,bw=1,2: REM red and
      blue for board
   15 PAPER bw: INK bb: CLS
   20 PLOT 79,128: REM border
   30 DRAW 65,0: DRAW 0,-65
   40 DRAW -65,0: DRAW 0,65
   50 PAPER bb
   60 REM board
   70 FOR n=0 TO 3: FOR m=0 TO 3
   80 PRINT AT 6+2*n, 11+2*m;"  "
   90 PRINT AT 7+2*n, 10+2*m;"  "
   100 NEXT m: NEXT n
   110 PAPER 8
   120 pw,pb=6,5: REM colours of
        white and black pieces
   200 DIM b$(8,8): REM positions of pieces
   205 REM set up initial positions
   210 b$(1)="rnbqkbnr"
   220 b$(2)="pppppppp"
   230 b$(7)="PPPPPPPP"