(disk-at-once, dao) A method of writing in which one or more tracks are written in a single operation. The laser will not stop until the whole disk recording is finished and the disk is closedr -- hence no Run blocks and no clicks between audio tracks. (See also Track-at-Once.) disk-at-Once has only been added/available with the recent generation of CD recorders and recent firmware upgrades. For more information, read "Disk-at-Once, Track-at-Once and Packet Writing ".