Yamaha CRW-70 Track-at-Once(TAO), Session-at-Once(SAO), Appendix

Appendix

Track-at-Once (TAO)

This method is used to write data on a disc on a track-by-track basis. A track can be defined as the smallest unit of area that contains an ordinary program, pictorial data, text data, etc. This method allows you to add data to the same disc, one track of data at a time, as long as there is free space left on the disc. Discs that contain data recorded in several different sessions (writing of tracks) are referred to as multi-session discs.

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		Data			Data		Data
		Track 1			Track 2		Track 3		Data can be
										added if there is
	1st session			2nd session			3rd session
									free space left on the disc.
		Lead	-out		Lead	-out		Lead	-out
Lead-in
		/Lead-in			/Lead-in

Note

Multi-session discs cannot be played on any ordinary audio CD player, except when data is recorded in a single session, or except for the first session.

Session-at-Once (SAO)

This method is used to write data on a disc on a session-by-session basis. Unlike Track-at-Once described above, Session-at-Once allows you to record multiple tracks onto a disc at one time. CD EXTRA, for example, uses this method to record multiple pieces of audio data (or multiple tracks) in the first session and information required for computers in the second session. This method allows you to add data to the same disc, one session at a time, as long as there is free space left on it. As is the case with discs containing data recorded by Track-at-Once method, discs containing data recorded by this method can also be called multi-session discs, provided that data is written in several different sessions.

Example: CD EXTRA

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	Audio data		Audio data		Audio data			Audio data
		Track 1		Track 2		Track 3		Track 4
			1st session					2nd session
Lead-in						Lead	-out/	Lead	-out
						Lead-in

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