INT 33h,  0Ah (10)       Set Text Cursor

    Selects the software or hardware text cursor.

       On entry:      AX         0Ah
                      BX         Cursor select
                      CX         Screen mask value/scan line start
                      DX         Cursor mask value/scan line stop

       Returns:       Nothing

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    Function 0Ah selects the software or hardware text cursor. The value of
    BX specifies wich cursor is selected. If BX is 0, the software text
    cursor is selected. If BX is 1, the hardware text cursor is selected.

    If the software text cursor is selected, CX and DX must specify the
    screen and cursor masks. These masks define the attributes of a
    character when the cursor is over it. Theese mask values depend on the
    display adapter in the computer.

    If the hardware text cursor is selected, CX and DX must specify the line
    numbers of the first and the last scan lines in the cursor. These line
    numbers depend on the display adapter in the computer.