track at once (TAO)

Track-at-Once (TAO) is an operating mode for burning compact discs( CD). In this mode, only one track is burned at a time, after which the laser beam is switched off. Additional tracks can be burned onto the compact disc as long as sufficient space is available.

This writing method is used for multisession CDs. The advantage of this method is that the compact disc is not written completely, but only with as many tracks as the data volume requires. The disadvantage is that the recording beam must be readjusted each time the disc is rewritten. In addition, the renewed writing process causes a set-up process to take place between the last track and the new track, which results in an interruption of the spiral-like track. When the compact disc is played, this transition causes an error, which is, however, corrected by the error correction.

The directory of the compact disc that is in the Program Memory Area( PMA) during the writing process is written to the lead-in after the last track is burned.