Abstract: A telephone includes a telephone circuit, a connector, and a switch. The connector is capable of being connected to a voice input/output interface in a network for a computer. The switch makes a selection as to whether a hand-set having a microphone and a loudspeaker is to be connected to the connector or to the telephone circuit. In this telephone, a hand-set accessory therefor can also be connected, as a voice input/output device for the personal computer, to the voice input/output interface for the computer network.

Abstract: In a circuit for producing an output signal under selective control of a control signal produced by a processor used in combination, a bar code reader and an optical communication receiver comprise in common a first low pass filter having a first cutoff frequency to produce a first low pass filtered signal. The optical communication receiver comprises a first digitizer connected to the first low pass filter for digitizing the first low pass filtered signal to supply a first digital signal to a serial communication unit. The bar code reader comprises a second low pass filter having a second cutoff frequency and connected to the first low pass filter for filtering the first low pass filtered signal to produce a second low pass filtered signal. A second digitizer is connected to the second low pass filter for digitizing the second low pass filtered signal to supply a second digital signal to an interrupt control unit.