High-rate writing of data recorded on a CD into a hard disk drive (HDD) is performed while reproducing data read out of the CD at the standard bit rate prescribed for the CD. PCM data corresponding to a playback time of 10 seconds, for example, is read out of a CD and stored in a memory. The data is read out of the memory at appropriate timing and outputted after being converted into an analog audio signal by a D/A converter. In parallel, data for writing is read out of the CD in succession to reading of the data for playback and stored in the memory. The data read out of the memory is coded and compressed by an encoder and then stored in the memory. The compressed data is read out of the memory in units of a certain amount suitable for writing in an HDD and then written in the HDD. When the data stored in the memory for playback has become smaller than a predetermined amount, an interrupt is generated during the writing process with the processing, which is given top priority, so that a next set of playback data is read out of the CD and stored in the memory.