SCREEN                   Set Screen Attributes                      Statement

 SCREEN [mode][,[colorflag]][,[apage]][,[vpage]]

    Sets screen parameters for use by subsequent statements.

        mode    A numeric expression. Must be 0, 1, 2, 7, 8, 9, or 10. See
                table below.

   colorflag    A numeric expression. Turns color on or off for composite
                monitors (color is always on for RGB monitors). In text
                mode, a zero value turns color off; a nonzero value turns
                color on. Works the opposite way in medium-resolution
                graphics mode: A zero value turns color on, while a
                nonzero value turns color off. In screen mode 2, colorflag
                is irrelevant.

       apage    An integer expression specifying the active screen page
                (the page written to by statements that output to the
                screen). Valid only in screen modes 0, 7, 8, 9, and 10.
                Legal values depend on screen mode (see table below).

       vpage    An integer expression specifying the visual screen page
                (the page displayed on screen; may be different from the
                active page). Valid only in screen modes 0, 7, 8, 9, and
                10. Legal values depend on screen mode (see table below).

    Screen modes:

------------------------------------------------------------------------
SCREEN 0  | 40 x 25 text | 16 colors, 2 attributes (CGA) | MDA, CGA, EGA
          | 80 x 25 text | 16 colors, 16 attributes (EGA |
----------+--------------+-------------------------------+--------------
SCREEN 1  | 320 x 200    | 16 colors, 4 attributes       | CGA, EGA
          | 40 x 25 text |                               |
----------+--------------+-------------------------------+--------------
SCREEN 2  | 640 x 200    | 16 colors, 2 attributes       | CGA, EGA
          | 80 x 25 text |                               |
----------+--------------+-------------------------------+--------------
SCREEN 7  | 320 x 200    | 16 colors, 16 attributes      | EGA only
          | 40 x 25 text | 2 pages if 64K on EGA         |
          |              | 4 pages if 128K on EGA        |
          |              | 8 pages if 256K on EGA        |
----------+--------------+-------------------------------+--------------
SCREEN 8  | 640 x 200    | 16 colors, 16 attributes      | EGA only
          | 80 x 25 text | 1 page if 64K on EGA          |
          |              | 2 pages if 128K on EGA        |
          |              | 4 pages if 256K on EGA        |
----------+--------------+-------------------------------+--------------
SCREEN 9  | 640 x 350    | 16 colors, 16 attributes      | EGA only
          | 80 x 25 text |    if >64K on EGA;            |
          |   in 8 x 14  | 16 colors, 4 attributes       |
          |   matrix     |    if 64K on EGA;             |
          |              | 2 pages if 256K on EGA        |
----------+--------------+-------------------------------+--------------
SCREEN 10 | 640 x 350    | 9 pseudo colors, 4 attributes | EGA only
          | 80 x 25 text | 2 pages if 256K on EGA        |
          |   in 8 x 14  |                               |
          |   matrix     |                               |
------------------------------------------------------------------------

      Notes:    All arguments are optional; omitted parameters retain
                former values.

                All display pages share a single cursor. Therefore, it's
                advisable to save cursor position (with POS and CSRLIN)
                when switching pages.

                If a valid SCREEN statement results in a new display mode,
                BASIC erases the screen and sets colors to white
                (foreground) on black (background and border). If a SCREEN
                statement does not produce a new display mode, BASIC does
                not erase the screen.