Okay, we have basically covered most of the drive but not the BURN-Proof technology yet. So, here we are.

First of all, the cover on the manual nicely prints the following statement - "BURN-Proof stands for proof against buffer under run error not for proof against burning." Wow, that is one funny line, don't you think? :D

Anyway, a quick check at http://www.burn-proof.com/ reveals more about the technology.

BURN-Proof, it would seem, actually stands for Buffer Under RuN error Proof. It is also a trademark of SANYO Electric Co. Ltd. because it is a proprietary technology developed by Sanyo to help prevent CD-writer drives from getting the buffer under-run errors.

Well, just ask anyone who bought a CD-RW drive a couple of years ago. Chances are they have been plagued with the buffer under-run problems before. Buffer under-runs occur when the stream of data to the CD writer gets disrupted. And to keep this stream of data constant, manufacturers have added a cache buffer between the data source and the CD writer. So, data is now stored into the buffer first which is then fed to the drive at a constant rate.

However, the computer might become too busy to refill the buffer and if the CD writer drive finishes writing all the data from the buffer, a buffer under-run occurs and renders the CD useless. Take a look at the illustration I got from the BURN-Proof site. The rather comical illustration below shows an occurrence of the buffer under-run error.

courtesy of http://www.burn-proof.com/

So, in a sense, if a drive is able to stop recording when the computer is too busy to supply data to the drive and continue when data is resupplied, then the buffer under-run errors can not only be avoided but resolved once and for all!

And this is exactly what BURN-Proof does. Take a look again at another illustration I got from the BURN-Proof site. It briefly shows how BURN-Proof works.

courtesy of http://www.burn-proof.com/

As you can see, when the computer is too busy to send data to the drive, the BURN-Proof drive simply stops writing and then continue again when data is resupplied. But for a more detailed overview of the technology, let's take a look at what actually happens.

As you can see above, when a buffer under-run occurs, the drive stops writing. It then stores the write data which is the appropriate location according to the EFM pattern. In other words, it remembers exactly where it last stopped. The drive will then pause and wait for more data to be re-supplied.

And when data is re-supplied by the computer, the drive will prepare to restart recording by retracing its previous write area. It then compares the data in the buffer with the recorded data and then synchronizes the data. It would now detect the exact final recording point. This is easily achieved by re-accessing the previously stored write data that keeps the location of the point of pause. It uses that data to control the status of the buffer and the servo. Finally, data is re-recorded at the point of initial pause. As such, it is as if there wasn't any pause and thus data was not lost.

So, that's how BURN-Proof basically works. However, some early users of BURN-Proof drives had some worries over the quality of the 'link portion' which is the result of how BURN-Proof works. For those who are wondering what a link portion is, it is the point where the recording of data paused and resumed. The initial generation of BURN-Proof drives created a gap between the point of pause and resumption. The official BURN-Proof site reacted with a 'BURN-Proof special lecture' on this particular issue. So, let's take a look at the explanation.