The drive does not recognize it. This is not an unusual problem, especially when a desktop computer is used for recording. One or both of these are usually missing or corrupted when a drive will not recognize a recorded CD-R. Various parts of the recording system can cause such a flaw. The TOC contains ATime locations for the beginning and end of every logical track. An unwise choice of recording method can lead to TOC problems because some methods do not write the TOC until the end of a recording when the session is finalized, or closed.
Data flow to the write laser is continuous, and opportunities for errors are minimized.
Buffer underrun errors are normally reported by the recording software if power management, screen savers, or other resident operations fatally preempt the flow of information to the writer. Three distinct recordings must be flawlessly completed, creating many possibilities of handshaking conflicts between the host, recording software, SCSI bus, and the writer. A flawed TOC can result from bugs in this handshaking process that actually occur, as witnessed by the frequent release of firmware revisions for writers, new SCSI drivers, and recording software updates. Multisession recording is another potential cause of read failures. The TOC contains track locations for only that session unless recording software supports linked multisession.