The Scroll Display Area routine scrolls a rectangular region of a
    virtual display.

    Format

      SMG$SCROLL_DISPLAY_AREA  display-id [,start-row]

                               [,start-column] [,height]

                               [,width] [,direction] [,count]

1  –  Returns

    OpenVMS usage:cond_value
    type:         longword (unsigned)
    access:       write only
    mechanism:    by value

2  –  Arguments

 display-id

    OpenVMS usage:identifier
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference

    Specifies the virtual display in which scrolling takes place. The
    display-id argument is the address of an unsigned longword that
    contains the display identifier.

    The display identifier is returned by SMG$CREATE_VIRTUAL_DISPLAY.

 start-row

    OpenVMS usage:longword_signed
    type:         longword (signed)
    access:       read only
    mechanism:    by reference

    Specifies the first row of the scrolling region. The start-row
    argument is the address of a signed longword that contains the
    starting row.

    If start-row is omitted, row 1 of the specified virtual display
    is used.

 start-column

    OpenVMS usage:longword_signed
    type:         longword (signed)
    access:       read only
    mechanism:    by reference

    Specifies the first column of the scrolling region. The start-
    column argument is the address of a signed longword that contains
    the starting column.

    If omitted, column 1 of the specified virtual display is used.

 height

    OpenVMS usage:longword_signed
    type:         longword (signed)
    access:       read only
    mechanism:    by reference

    Specifies the number of rows in the scrolling region. The height
    argument is the address of a signed longword that contains the
    number of rows.

    If omitted, this value defaults to either the height of the
    virtual scrolling region (if one has been explicitly set with
    SMG$SET_DISPLAY_SCROLL_REGION) or the height of the specified
    virtual display.

    When scrolling a portion of a virtual display that contains
    double-height, double-width (highwide) characters, it is
    recommended that you scroll the display an even number of times.

 width

    OpenVMS usage:longword_signed
    type:         longword (signed)
    access:       read only
    mechanism:    by reference

    Specifies the number of columns in the scrolling region. The
    width argument is the address of a signed longword that contains
    the number of columns.

    If omitted, this value defaults to the width of the specified
    virtual display.

 direction

    OpenVMS usage:mask_longword
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference

    Specifies the direction to scroll. The direction argument is the
    address of a longword bit mask that contains the direction code.

    Valid values are SMG$M_UP, SMG$M_DOWN, SMG$M_RIGHT, and SMG$M_
    LEFT. SMG$M_UP is the default.

 count

    OpenVMS usage:longword_signed
    type:         longword (signed)
    access:       read only
    mechanism:    by reference

    Specifies the number of lines or columns to scroll. The count
    argument is the address of a signed longword that contains the
    number of units (lines or columns) to scroll. If omitted, one
    unit is scrolled.