 Sample image
The task is to demonstrate the creation of a series of vertical pinstripes across the entire width of the display.

 in the first quarter the pinstripes should alternate one pixel white, one pixel black = 1 pixel wide vertical pinestripes
 Quarter of the way down the display, we can switch to a wider 2 pixel wide vertical pinstripe pattern, alternating two pixels white, two pixels black. 
 Half way down the display, we switch to 3 pixels wide, 
 for the lower quarter of the display we use 4 pixels.


c.f. Colour_pinstripe/Display

10 FOR W=1 TO 4
20 FOR I=0 TO 63 STEP 2*W
30 FOR J=1 TO W
40 FOR K=43-11*(W-1) TO 33-11*(W-1) STEP -1
50 PLOT I+J,K
60 NEXT K
70 NEXT J
80 NEXT I
90 NEXT W