 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

include c:\cxpl\codes;          \include 'code' declarations
int X, Y, W, C;
[SetVid($13);                   \320x200x8 graphics
for Y:= 0 to 200-1 do           \for all the scan lines...
    [W:= Y/50 + 1;              \width of stripe = 1, 2, 3, 4
    C:= 0;                      \set color to black so first pixel becomes white
    for X:= 0 to 320-1 do       \for all the pixels on a scan line...
        [if rem(X/W) = 0 then C:= C xor $0F;    \alternate B&W
        Point(X, Y, C);         \set pixel at X,Y to color C
        ];
    ];
X:= ChIn(1);                    \wait for keystroke
SetVid(3);                      \restore normal text display
]