It is an object of the present invention to propose a sheet computer that eliminates the drawback in operational speed caused by clock delays of a system clock and that is capable of high speed operation. In order to achieve this object, in the sheet computer of the present invention, a display circuit and peripheral circuits connected to the display circuit are fabricated on the same substratum and the peripheral circuits constitute an asynchronous system without global clocking. In the asynchronous system, processes constituting minimum function circuits perform mutual handshaking by channels and drive events actively or passively. The asynchronous system does not use global clocking and it is therefore possible to implement lower power consumption and a higher operational speed.