Abstract: The multiple-channel wireless input unit is applied to a computer system that involves the use of wireless peripherals. Each different input device is respectively controlled by a CPU to transmit signals from its transmitter at a different channel, while its receptor controls a CPU that in turn controls a scanning device to scan the input signals at different channels. The signals are then transmitted to the computer through a USP port. The receptor receives signals at different times by scanning operation to achieve the purpose of simultaneous reception of two packets of signals in a time-divided and labor-divided fashion, and upgrade the operational efficiency of the wireless input unit.

Abstract: A method for forming a keyboard switching circuit without generating phantom phenomenon is disclosed. The method includes the steps of (1) forming a matrix of nodes with input/output terminals of the keyboard circuit; (2) selecting nodes from the matrix to define a reference diagonal line which divides the matrix into upper and lower portions; (3) selectively selecting nodes of the matrix in the upper and/or lower portions to define diagonal lines parallel to the reference line, the diagonal lines being located at different distance from the reference lines and the nodes of the diagonal lines forming no rectangle with each other; and (4) setting switches in the selected nodes. Since no rectangle can be formed among the switches, no reverse current may be caused by simultaneous actuation of three switches of a rectangle and thus effectively eliminating phantom phenomenon.