PURPOSE: To accelerate the rise of a sound by writing a sample in each channel to a buffer from an input/ouput part at the time of storage and from a storage medium at the time of reproduction and reading it when first sample data in a last channel are written.

CONSTITUTION: First of all, digital data are fetched from the input/output part 1 and recorded in the buffers 4, 4' at an allowable transfer rate VO alternately. Then, when a head 5 ends the seeking a target track and sector, the data in the buffer 4 are transferred into the storage medium at the allowable transfer rate VS. The data from the input/output part 1 are recorded in the buffer 4' while transferring. When the data in the buffer 4 are ended to record in the medium 6, seeking is performed succeedingly and the data in the buffer 4' are recorded in the medium 6. Thereafter, the operation is repeated by required number of times. At this time, the data by 1 block are stored in the buffer 4 temporarily so that continuous storage or reproduction of the data is secured and the next data by one block are stored in the buffer 4 while the data are outputted.