Accordingly, an improved method for recording data on an optical medium is
disclosed which includes receiving and encoding a first set of data frames
by a CIRC encoder to generate a second set of data frames. A control byte
is then added to each of the second set of data frames to generate a third
set of data frames. The third plurality of frames of data are received and
encoded at an EFM encoder to generate a section comprising a plurality of
Channel frames. The control byte of a sequentially first one of the third
set of data frames is replaced with a SYNC 0' byte selected from the
limited group of previously unassigned fourteen-bit combinations. The
control byte of a sequentially second one of the third set of data frames
is also replaced with a SYNC 1' byte selected from the same group. The
SYNC 1' byte is different from the SYNC 0' byte, and the SYNC 0' and SYNC
1' bytes are selected such that at least one of the following conditions
is met: (a) the SYNC 0' byte is not equal to 00100000000001, and (b) the
SYNC 1' byte is not equal to 00000000010010. The section is then recorded
on the optical medium. Using this method, a proprietary data format
similar to a standard data format may easily be generated. The proprietary
data format may not be read or copied by standard CD playback and copying
systems.
