PC Hardware in a Nutshell, Second Edition

BURN-Proof Technology

Anyone who uses a CD writer has made coasters , the common term for a ruined CD-R blank. Although packet writing and UDF effectively eliminate coasters, packet-writing software is useless for batch-mode tasks, like duplicating CDs. Those tasks demand premastering software, which unfortunately is by no means immune to generating coasters.

Until recently, CD premastering was inherently an isochronous (time-dependent) process, because data had to be delivered to the write head in a continuous stream from the time the write began until it completed. If that stream was interrupted long enough for the data stored in the writer’s buffer to be exhausted—an accident called a buffer underrun —the blank was ruined. Buffer underruns were particularly common with IDE/ATAPI CD writers, although they were by no means rare even on SCSI burners.

We say until recently, because a new technology called BURN-Proof (Buffer UnderRuN-Proof), developed by Sanyo and licensed to CD writer makers, effectively makes buffer underruns a thing of the past. In simple terms, BURN-Proof turns off the writing laser when it runs out of data to write (duh), and then, when data is again available, restarts the burn exactly where it left off. In effect, BURN-Proof converts CD writing from an isochronous process to an asynchronous one.

BURN-Proof works by constantly monitoring the status of the CD writer’s buffer to detect a potential buffer underrun condition. If the amount of buffered data falls ...