INT 62 u - FGDRIVER v3.03 - "FG_SCROLL" - VERTICALLY SCROLL SCREEN REGION
        AX = 0089h
        BX = left edge column
        CX = right edge column
        DX = top edge row
        SI = bottom edge row
        DI = number of pixels by which to scroll (positive scrolls up,
                negative scrolls down)
        ES = type of scroll
            0000h circular (rows scrolled off are copied to vacated rows)
            else vacated rows are filled with the current color
Notes:  For FGDRIVER v1.10, this function was "FG_SOUNDS" (see AX=009Eh);
          "FG_SCROLL" was AX=0067h
        In graphics modes, the left and right edges are adjusted to byte
          boundaries if necessary
        Circular scrolling uses part of the hidden page as a workspace
SeeAlso: AX=0071h,AX=0095h

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