VIEW                     Define Screen Window or Viewport

 VIEW [SCREEN] [(x1,y1) - (x2,y2) [,[color] [,border]]]]

    Defines a screen subset, or viewport. A viewport is an area of a
    graphics screen where future output is allowed. Output to areas not in
    the viewport will not be displayed.

      SCREEN    If omitted, the coordinates of all subsequent graphics
                statements are measured relative to the defined viewport,
                whose upper left corner becomes 0,0. If included, 0,0 is
                still the upper left corner of the screen, but only those
                points that fall within the defined viewport are visible.

       x1,y1    Upper-left corner (column, row) of the viewport, in
                pixels.

       x2,y2    Lower-right corner (column, row) of the viewport, in
                pixels.

       color    If included, Turbo Basic fills the viewport with the
                specified color. Allowed values are 0 to 3 in medium
                resolution, 0 or 1 in high resolution.

      border    If included, Turbo Basic draws a border, in a specified
                color, around the defined viewport. Allowed values are 0
                to 3 in medium resolution, 0 or 1 in high resolution.

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      Notes:    BASIC sorts the coordinates x1,x2,y1, and y2, so that the
                lower value of x and the lower value of y specify the
                upper left corner, regardless of how the coordinates are
                presented; i.e., VIEW (280,120)-(140,180) would be
                equivalent to VIEW (140,120)-(280,180).

                VIEW with no argument redefines the viewport to the full
                screen.

                Multiple viewports may be defined, but only the most
                recent definition is active.

                A defined viewport is disabled by a RUN statement or a
                change in SCREEN attributes.

                With a viewport in effect, CLS clears only the viewport,
                not the entire screen.