A method for detecting and separating vertical and horizontal synchronous
signals from a computer system. The input forms of the vertical and
horizontal synchronous signals from the computer system are detected by
scanning a vertical synchronous signal terminal, a horizontal/composite
synchronous signal terminal and a synchronous-on-green terminal of the
computer system. In accordance with the detected input forms, the
vertical and horizontal synchronous signals are separated from each other
and then adjusted in polarity. Therefore, the present invention requires
no separate hardware for the separation and polarity adjustment of the
vertical and horizontal synchronous signals, resulting in simplification
in circuit construction and reductions in number of used components and
size of a printed circuit board.