DW      RESTOREBITMAP   ; Write screen memory to the screen.

  Input:
     ES:BX      Points to the buffer in system memory
                to be read. ES:[BX] contains the width of the
                rectangle -1. ES:[BX+2] contains the heigth of
                the rectangle -1.

     CX         The upper left X coordinate of the rectangle.
     DX         The upper left Y coordinate of the rectangle.

     AL         The pixel operation to use when transferring
                the image into graphics memory. Write mode for
                block writing.
                  0: Overwrite mode
                  1: XOR mode
                  2: OR mode
                  3: AND mode
                  4: Complement mode

  Return:
     Nothing

The RESTOREBITMAP vector is used to load screen pixels from the system
memory. The routine reads a stream of bytes from the system memory into the
rectangle defined by (SI,DI) - (CX,DX). The value in the AL register
defines the mode that is used for the write. The following table defines
the values of the available write modes:

        Pixel Operation                 Code
         Overwrite mode                  0
         Logical XOR                     1
         Logical OR                      2
         Logical AND                     3
         Complement                      4