Abstract: A transmitter/receiver module of cordless keyboard assembly adapted to be received and fixed inside a disk driver slot provided on the front panel of a computer casing is disclosed, including a frame sized to be received within the disk driver slot, having two lateral sides each having a slot opposite to each other for receiving a transmitter/receiver circuit module in the form of a circuit board which includes an encoder for setting the operation frequency of the transmitter/receiver circuit by means of at least one manually depressible button provided on the circuit module. The circuit module also has a display for showing the operation frequency thereof. A cover lid made of a material through which the signal from/toward the transmitter/receiver circuit module is transmittable is provided to cover the front opening of the frame. The cover lid is provided with an opening for access to the depessible button and observation of the display.