Abstract: A CD (compact disc) system is provided in a software form, by which a virtual CD-R (compact disc recordable) can be formed on a computer, and an actual CD-R can be easily and quickly formed from this formed virtual CD-R. While original data is processed, a virtual CD-R is formed in accordance with a structural requirement of a CD into a storage means employed in the computer. Furthermore, an actual CD-R is formed from the above-explained CD-R.