Disk recording system by data reading and straightforward conversion to digital data

EFM signals including margin bits read from a CD are passed to an EFM copy circuit. After cutting one bit from the margin bits, the EFM copy circuit stores the EFM signals with the margin bits into a buffer. The EFM copy circuit reads the EFM signals including the margin bits from the buffer, decompresses the margin bits, and supplies the EFM signals with the decompressed margin bits to a write strategy circuit. Then, the EFM signals are written onto a CDR from the recording start position on the CDR, which is detected by the information from a WBL detection circuit. The start address of the EFM data to be read from the buffer is located from subcode transferred from a subcode detaching circuit to the EFM copy circuit. In this manner, the content of a CD with copy guard protection can be copied to another disk.