Sanyo Electric Co. Ltd. has developed a new technology which it says prevents the copying of CD-ROM discs onto CD-R (CD-recordable) discs. When users try to copy a CD-ROM disc protected with the technology onto a CD-R disc, a hidden file, which consists of data that causes errors, will be read and prevent illegal copying, according to Tamotsu Itoi, a spokesman for Sanyo. This file will be hidden on discs at the pressing stage. The size and the location of this hidden file vary for each master disc, making it harder for software which can detect the hidden file to be developed, Itoi said. The new system from Sanyo is the latest in a number of technologies developed to prevent pirating of CD-ROMs. Most of these have failed because programmers have found ways around the systems and developed software to help users bypass the protection. Sanyo said it will keep working on the technology in an attempt to break this vicious circle, said Itoi..