A wireless telephone has a mobile unit having a first computer and a base unit having a second computer and a recording device. Push button requests for starting and stopping recording by the base unit, and end of speech indications for stopping recording are processed by the first computer and transmitted as data signals to the second computer for implementation in the base unit. The second computer acknowledges recording starts to the first computer.

A battery management chip which controls charging and discharging currents of a rechargeable battery. A further novel teaching set forth in the present application is an integrated circuit which includes a crystal-controlled oscillator for precise time measurement. Crystal-controlled oscillators are normally fairly power-hungry circuits, and such circuits would not normally be used in the low-power part unless needed. However, according to this innovative teaching, the precise time integration provided by the crystal oscillator is significantly advantageous, since it permits accurate time integration to derive the present state of the battery after multiple charge and discharge cycles. In addition, in the presently preferred embodiment, a low-power crystal-controlled oscillator is used.

A facsimile apparatus with an audio response function according to this invention includes an interface for closing a telephone line in response to detection of a ring signal, a response message transmitting device for transmitting a response message after the interface closes the telephone line, a communication start signal detecting device for detecting a facsimile communication start signal inputted from the telephone line, a facsimile communication device for performing facsimile communication, and a change circuit for connecting the telephone line to the facsimile communication device when the communication start signal detecting device detects the facsimile communication start signal in the case where the response message transmitting device transmits the response message. According to this structure, when the ring signal is inputted from the telephone line, the interface closes the telephone line and the response message transmitting device transmits the response message. In addition, when the facsimile communication start signal is inputted from the telephone line, this is detected by the communication start signal detecting device and the change circuit connects the telephone line to the facsimile communication device.

When an incoming call is received via a telephone line in an automatic answering/recording mode, a response message stored in a recording memory is read out by a burst signal processing section at the timing of expansion processing for restoration of reception speech data, and a message sent from a caller is written in the recording memory at the timing of compression processing for generation of transmission speech data, thereby providing a simple digital radio telephone apparatus capable of performing a simultaneous answering/recording operation.

A digital telephone answering device (DTAD) that allows messages to be forwarded to certain internal mailboxes. Random access memory (RAM) is flexibly and dynamically controlled by a microprocessor or controller. Audio signals in the form of voice messages are digitized and stored in the RAM. Messages can be sorted and allocated to specific mailboxes and made retrievable by pressing a button assigned to that mailbox. Messages can also be moved or re-assigned from a common message area to a certain mailbox or mailboxes. Outgoing messages are also stored in RAM and can be of sufficient number to have an outgoing message correspond to each incoming message storage area. The normal message recording and message playback functions of the DTAD may be activated after the call has been answered on the receiving side. Memos can be appended to messages that have been moved or re-assigned from a common message area to a certain mailbox or mailboxes.