BurnProof, JustLink & other "Coaster Prevention" Technologies

Burn-Proof, JustLink, etc.

A look at CD Writers with "Coaster Prevention Technology"

Introduction

A CD writer with buffer underrun protection such as "Burn-Proof" or "JustLink" (etc.) virtually eliminates the problem of buffer underruns that can ruin a CD you are recording. Indeed, BURN-Proof, as it is sometimes written, is ostensibly an acronym for "Buffer-Under-Run Proof." Note that drives with a Burn-Proof feature can get away with a 2MB buffer without risking under-runs. The only time a buffer under-run will occur on a Burn-Proof-enabled drive is if the source media that is being copied is so badly damaged that reading of the data cannot continue.

Goodbye, ruined CDs!

Sanyo's Burn-Proof technology, like variants developed by Yamaha or Ricoh, consists of a firmware routine in the drive that watches the status of the buffer. When the buffer is about to empty, the Burn-Proof controller sends a command to turn off the writing laser. Then, when the empty buffer condition is resolved, it turns the laser back on again. The drive's built-in error correction mechanism treats the tiny gap created during this interruption as it would any minor defect in the media -- it simply writes around it. Although Burn-Proof was originally developed by Sanyo and has been licensed to several manufacturers (most notably, Plextor and LaCie), Ricoh, Lite-On, Yamaha, HP (its latest dvd100i, notes Extremetech, uses the Ricoh technology for its buffer underrun protection system) and Toshiba have similar systems on some -- but not all -- of their CD recorders.

In fact, the original Burn-Proof system writes a fairly crude marker gap, approximately 40 micrometers in size. An updated version of Burn-Proof is said to reduce the gap to 2-5 micrometers. The competing JustLink system writes a 2-micrometer gap.

Here is an excerpt from the documentation for the Ricoh MP7125A, the first drive to incorporate JustLink technology, explaining how it works:

JustLink works on the following principle:

1. The amount of data accumulated in the buffer memory is always monitored during writing.
2. If, for some reason, the data transfer speed from the computer falls below the writing speed, the amount of data accumulated in the buffer memory falls.
3. When the amount of data in the buffer memory falls below a certain level, and the possibility of a buffer under run error is predicted if the writing continues, writing is intentionally suspended for the time being.
4. During the time that the writing is suspended, data transferred from the computer accumulates in the buffer memory.
5. When enough data has accumulated, writing is resumed from the point directly after the point where it was suspended, and monitoring of the amount of data in the buffer memory is re-commenced.

The greatest difference when compared to other buffer under run prevention technologies is the fact that the gap (link section) between the part where writing was suspended and the part where writing was resumed is extremely small. This is actually why this technology has been called JustLink. Usually with other technologies a gap around 40µm (a data blank) is created, whereas JustLink gaps are always less than 2µm. You wouldn't expect C2 errors to occur at 40µm, when you're talking about 12x writing speed, but for argument's sake, if the current writing speed were to double to 24x, the link would be 80µm, in which case you wouldn't be able to negate the possibility of an error. In contrast, even with 24x writing speed, JustLink would leave a sufficient margin with a link section no larger than 4µm. In other words, the JustLink method has the scope and flexibility to cope with whatever writing speed....

StorageReview.com, meanwhile, maintains that any gap size less than 100 micrometers has no observable effect on the quality of burned data, so it probably doesn't matter much which buffer underrun technology you choose. And there are other buffer underrun protection technologies, too: Acer has "Seamless Link;" Sony offers "Power-Burn," Yamaha has "SafeBurn" (which, as far as we can tell, was formerly called "WasteProof,"), Oak has ExacLink,  Pioneer calls it "lossless linking"  -- and there are others, such as the "SuperLink" technology used in LG's CED-8160B, or the SMART-Burn technology from Mediatek. The key point is that any of these systems will virtually eliminate ruined CDs.

The following list is by no means comprehensive, but strives to compare some of the most popular CD burners on the market today with buffer underrun protection. Prices are approximate.

12x Burners

16x Burners

20 - 24x Burners

External/Portable Burners

"Combo Drive" Burners

Although all the buffer underrun protection variants are fundamentally similar, many consider the Ricoh-developed JustLink technology, with its extra-fine control of the writing laser, to be the least likely to create glitches on the resulting discs. Some of the faster drives, such as the 16x10x32x AOpen CRW1632, include a related technology called JustSpeed. It checks the media for compatibility with 12x and 16x write speeds, and thus avoids disc errors or, conversely, unnecessarily slow writing speeds.

On the other hand, almost everyone considers Plextor to be the best drive brand, overall. Some Plextor models include a feature somewhat similar to JustSpeed, which Plextor calls PowerRec. (Plextor Optimized Writing Error Reduction Control). The latest version, at this writing, is PowerRec II. It's a feature of our Quality Choice, the Plextor PX-W2410A.

We have been unable to confirm rumours that Plextor's parent company, Shinano Kenshi of Japan, in fact manufactures the LTR-12101 model for Taiwan-based Lite-On Tech, Corp.) In any event, the Plextor and Lite-On drives have very close average writing speeds, and the Lite-On drives (particularly the new LTR-24102B model), achieve very respectable scores in benchmark tests.

There have been a number of cases where rebadged drives have been based on a high-quality model for part of the production run, then quietly replaced by a much cheaper drive. Creative Labs is notorious for this, having sold, at various times, 8x4x32 drives based on components from Plextor, Samsung, SEC (Samsung), and two different Panasonic models. Similarly, some versions of the TDK VeloCD 12/10/32 are based on Plextor mechanisms and say "Burn-Proof" on the box; others say "JustLink" and are manufactured by Ricoh. Further complicating the issue, these rebadged drives sometimes won't accept firmware upgrades designed to fix problems in the original equipment manufacturer's hardware. As such, our standard "buyer beware" warning must apply to any drive from Creative Labs, HP (which has been using Sony drives in many of its models lately), Imation, Iomega, Smart & Friendly, TDK and other "manufacturers" who don't build their own hardware.

The ExacLink technology and SafeBurn buffer underrun protection features found on Mitsumi and Yamaha drives noted above are both based on technology developed by Oak Technology and both drives use Oak's OTI-9796 controller.

Problems noted

A glitch affects the NEC NR-7700A and TEAC CD-540E when used on motherboards based on the VIA KT133 or KT133A chipsets. These systems suffer slow and unstable recording at speeds higher than 4X and the recorder may refuse to recognize newly loaded discs. The solution is less than ideal: either of these drives works correctly only on the Secondary IDE channel with the DMA disabled -- and even so, this doesn't work on all systems.

As drives push the upper limit of speeds at which CD-recordable discs are capable of being written, a technology known as Zone-CLV writing becomes important. CLV stands for constant linear velocity; on drives supporting Z-CLV, the writing area is divided into zones, in which the recording speed varies. Plextor, for example, uses this technology in its high-speed PlexWriter PX-W2410A model, allowing it to attain up to 24x speeds. Sanyo and Ricoh also provide Z-CLV writing on selected models. Note that some less expensive drives (e.g., Sanyo/TDK and LiteOn) don't support this Z-CLV mode at all writing speeds.

Software

Not all CD recording software titles support the Burn-Proof/JustLink features of these drives. Here is a partial list of titles that do:

• CDRWin 3.8c or newer (PC)
• Nero Burning ROM 5.x or newer (PC) (Our Editor's Choice)
• NTI CD-Maker 2000 (PC)
• Roxio Easy CD Creator 5 or newer (PC)
• Roxio Toast 4.1.2 or newer (Mac)
• Iomega HotBurn (PC and Mac)

We're particularly impressed with Ahead's Nero. Version 5.5.4.0 supports the great-sounding mp3PRO audio format, and can write DVD data to discs on supported recorders. Other plug-ins add support for writing MPEG2 (Super VideoCD format) and WMA (Windows Media Audio) files to disc. It was completely reliable in our tests.

Conclusion

At around $135, the AOpen CRW1232A (which is actually a rebadged Ricoh 7125A) comes in at one of the lowest prices in this roundup for a 12x10x32x drive. It supports the superior JustLink technology and includes all the extras you'll need to install it: an installation manual, four screws, IDE cable, analog audio cable, even an MP3 encoder and a couple of blank discs. It comes with the acclaimed Nero 5 CD-burning software package, albeit in a version specially keyed to only work with this drive. The biggest drawback to this drive is it's noise level while seeking -- it's unusually noisy, compared to most 32x readers. Still, it's one of the fastest 12x writers on the market, capable of burning a disc in just six and a half minutes. It's a tossup with the faster AOpen CRW1632 as our Value Choice.

The Plextor PX-W2410A.is our Quality Choice and the Lite-On LTR-24102B, the fastest drive surveyed here, is our High Performance Choice. Its support of Overburning (up to 99 minutes!) and Raw mode copying will make it an attractive choice for those looking to copy exotic disc formats.

The Acer MiniRW is the flexibility king, with PCMCIA, USB 1.1 and FireWire ports, making it our Portability Choice. Interestingly, although the Easy CD Creator version shipped with the drive does not support Burn-Proof or JustLink, the Seamless Link feature is turned on in the drive's firmware by default and doesn't seem to need software support at all.

We'll decline to name an editor's choice in the DVD authoring category until we've had a chance to extensively test the new HP dvd100i. (We've only had a brief look at HP's DVD writer so far.) It looks like a strong competitor to the popular Pioneer A03 "SuperDrive."

For Further Reading:

• CD-R FAQ: What is "BURN-Proof"- "JustLink"- "Waste-Proof"?
• http://www.cdrinfo.com/
• http://www.cdrlabs.com/
• Yamaha has released a FirmWare Update for its IDE and SCSI CRW2200E burners.
• www.digit-life.com looks at the best bets in its list of recommended CD-RW drives
• The Coaster Factory: What CD-Writer To Get

See the following sites fort more reading on this topic:

• ASCII24
• CDR-Info
• PC Watch