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How to Reliably Record Optical Discs

Six major factors influence your ability to create a working disc: interface type, drive buffer size, the location and condition of the data you want to record, the recording speed, whether the computer is performing other tasks while trying to create the disc, and the features available in your recording software. If you are having problems, there are some things you can check. The simplest thing you can do to ensure trouble-free recording is to make sure the drive has some form of buffer underrun protection. The data buffer in the drive holds information read from the original data source, so that if a pause in data reading occurs, there's less of a possibility of a buffer underrun until the on-drive buffer runs empty. Current drives with buffer underrun protection virtually eliminate this problem, no matter what size buffer is in the drive. Some mastering programs might offer an option to disable buffer underrun protection. However, you should leave it enabled at all times unless you are using an old drive that does not support this feature.

Buffer Underruns and Buffer Underrun Protection

Whenever a drive writes data to a disc in either DAO or TAO mode, it writes to the spiral track on the disc, alternating on and off to etch the pattern into the raw media. Originally, it was not possible for a drive to realign where it starts and stops writing like a hard drive can; after it started writing, it was necessary to continue until finished with the track or disc. Otherwise, the recording (and disc if it is not rewritable) would be ruined, creating a useless disc often referred to as a "coaster." To avoid this problem, the recording software, in combination with your system hardware, must be capable of delivering a consistent stream of data to the drive while it's writing.

Sanyo was the first to develop a technology that eliminates buffer underruns once and for all. It calls the technology BURN-Proof (BURN stands for buffer underrun), which sounds a little confusing (some people thought it prevented any writing on discs), but in practice it has proven to be excellent. Other technologies were developed by various vendors, including Ricoh's JustLink, Waste-Proof and Safeburn from Yamaha, SMART-Burn from Lite-On, and Superlink from Mediatek, among others. For a number of years, all recordable/rewritable drives have included some type of buffer underrun protection. Buffer underrun protection technology involves having a special chipset in the drive that monitors the drive buffer. When it anticipates that a buffer underrun might occur (the buffer is running low on data), it temporarily suspends the recording until more data fills the buffer. When the buffer is sufficiently restocked, the drive then locates exactly where the recording left off earlier and restarts recording again immediately after that position.

According to the Orange Book specification, gaps between data in a recording must not be more than 100 milliseconds in length. The buffer underrun technology can restart the recording with a gap of 40–45 milliseconds or less from where it left off, which is well within the specification. These small gaps are easily compensated for by the error correction built into the recording, so no data is lost.

If both your drive and recording software supports buffer underrun protection, you can multitask—do other things while burning discs—without fear of producing a bad recording.

Booting from a Floppy Disk with Optical Drive Support

Although modern OSs are distributed on bootable discs, you might need to boot from a floppy to start a restore process from a disk imaging utility or to install an older OS, such as Windows 9x or Me. Even if you are installing Windows 9x or Me in a virtualized environment such as those created with Microsoft Virtual PC or VMware, you need to boot the virtual machine with a floppy disc containing optical disc support before you can install the OS into the VM.

For an optical drive to function in a floppy boot environment, several drivers might be necessary:

  • A host adapter driver—A set of universal ATAPI and SCSI host adapter drivers are included on Windows 98/Me startup disks.
  • MSCDEX—Microsoft CD Extensions, which is included with DOS 6.0 and later, including the Windows 98/Me startup disks.

If you need to start a PC from a bootable floppy, the floppy must contain not only a bootable OS, but also the previously mentioned drivers; otherwise, the CD-ROM will be inaccessible.

You can find universal ATAPI and SCSI drivers on the Windows 98 and newer startup disks. Rather than create custom CONFIG.SYS and AUTOEXEC.BAT files, the best advice I can give is to merely boot from a Windows 98 or Me startup floppy because each time you boot from it, the proper drivers load and autodetect the optical drives, after which the drives are accessible. You can generate a Windows 98/Me startup disk on any system running Windows 98 or Me. If you don't have access to a Windows 98 or Me system, you can download an equivalent bootable floppy from www.bootdisk.com.

After you boot from a Windows 98/Me floppy, you see a menu that asks whether you want to boot with or without CD-ROM (and DVD) support. If you select yes, after the floppy finishes loading, you should be able to read discs in the optical drive.

Using an optical drive that conforms to the ATAPI specification under Windows does not require you to do anything. All the driver support for these drives is built into Windows 9x and later versions.

Bootable Optical Discs—El Torito

If your system BIOS is a version dated from 1998 or later, most likely it has "El Torito" support, which means it supports booting from a bootable optical disc. The El Torito name comes from the Phoenix/IBM Bootable CD-ROM Format Specification, which was actually named after the El Torito restaurant located near the Phoenix Software offices where the two engineers who developed the standard ate lunch. What El Torito means for the PC is the capability to boot from optical discs, which opens several possibilities, including creating bootable rescue discs, booting from newer OS discs when installing to new systems, creating bootable diagnostics and test discs, and more.

To create a bootable optical disc, ideally you need a burning application that allows the creation of bootable discs. Additionally, in some cases you need a bootable floppy that contains the drivers to support your CD drive in DOS mode (sometimes called real-mode drivers). The best source for these drivers (if needed) is a Windows 98 or Me startup floppy, which can be generated by any Windows 98 or Me system. Windows 98/Me startup disks can be used because these have the DOS-level CD-ROM support already configured and installed. If you don't have access to such a system to generate the disk, you can download one from www.bootdisk.com.

To create a bootable disc, simply follow the directions included with your burning application. Programs such as Nero and Roxio Media Creator make the creation of bootable discs relatively easy.

LightScribe and LabelFlash

There are two popular direct disc labeling systems, called LightScribe and LabelFlash. Hewlett-Packard (HP) developed the LightScribe direct disc labeling system in 2005 as a method for labeling CD (and later, DVD) discs without the need to print labels or use an inkjet printer equipped to print on CD or DVD media.

The top surface of a LightScribe disc is coated with a reactive dye that changes color when exposed to laser light. LightScribe uses the recording laser to etch text and graphics on the top surface of special LightScribe media. After the user records the disc, the user flips the disc over and runs a LightScribe program to transfer the desired design to the top of the disc. To prevent fading and surface damage, LightScribe discs should be stored in cases away from light when not in use.

LabelFlash was announced in October 2005 by Yamaha and Fujifilm. LabelFlash is based on the DiscT@2 ("disk tattoo") technology originally developed by Yamaha for writing text and graphics into the unused portion of the data side of a CD-R disc. However, LabelFlash can also write to the top side of media when the user flips the disc, just as with LightScribe. The top side of LabelFash media is designed to be more resistant to damage and to produce better image quality than LightScribe because the LabelFlash dye is 0.6mm below the disc surface.

The main drawback of either system is that they take up to half an hour or more to fully label a single disc. Another drawback is that both LightScribe and LabelFlash require drives, media, and software that support the specific system. For an updated list of products supporting these systems, visit the LightScribe (www.lightscribe.com) or LabelFlash (http://labelflash.jp) website.

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