INT 33h,  01h (1)        Show cursor

    Increments the internal cursor flag and, if the flag is 0, displays the
    cursor on the screen.

       On entry:      AX         01h

       Returns:       Nothing

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    Function 1 increments the internal corsorflag and, if the flag is 0,
    displays the cursor on the screen. The cursor tracks the motion of the
    mouse, changing position as the mouse changes position.

    The current value of the internal cursor flag depends on the number of
    calls that have been made to functions 1 and 2. The default flag value
    is -1; thus , after a reset, a call to function 1 displays the cursor.

    If the internal cursor flag is already 0, this function does nothing.