A control apparatus for controlling a plurality of computers is described. The control apparatus includes a memory, a clock generator, a clock switch circuit, and a main module. The clock switch circuit switches between a system clock and a corresponding clock of a digital video signal. The main module directly stores the digital video signal into the memory according to the corresponding clock through the clock switch circuit. The main module reads the digital video signal from the memory according to the system clock. The main module also receives a remote control signal sent from a remote computer to control the plurality of computers.