Mac CD‑writing has a head start over the PC, but recent arrivals like the Teac CD‑R50S come with both Mac and PC CD software as standard. Martin Walker plugs one in to see if writing your own CD is as easy as people make out.
Most people thinking of buying a CD‑R machine fall into one of two categories — those who think you just plug it in, switch it on, and start churning out loads of CDs, and those who have read so many horror stories about CDs burned on one machine which refuse to play on any other, or which refuse to reliably write with all but one make of blank discs, that they prefer to avoid the issue until the situation improves. Although CD‑R technology had many teething problems, and as recently as six months ago incompatibilities caused a lot of heartache for some people, CD‑Rs are now not only comparatively easy to use, but extremely reliable too. Part of the problem has been that some manufacturers have over‑simplified the use of CD writers, promoting them as some sort of super floppy drive — "just plug it in and back up 650Mb of your data, make your own audio CDs...". In reality, the expression "recording a CD" is a gross simplification of the processes involved. Unlike the glass master used in commercial CD replication, CD‑Rs use a blank disc that already has a spiral track groove which guides the laser. During the write process, once the laser is moving along this groove and heating up the surface of the disc, any interruption to the flow of data will result in an error — and you only get one chance to burn a CD‑R. A single error will result in an unuseable disc. Maintaining a smooth flow of data is vital, and this is why just having a fast CD‑R machine is not enough: you ideally also need a fast hard drive, SCSI interface, and well written software. In fact, the faster the CD writer, the more powerful the PC needed to maintain the data flow.
There are a wide variety of formats encompassing the many uses of CD‑R (see 'All the Colours of the Rainbow' box). Most musicians will, of course, be mainly interested in CD Audio (also known as CD‑DA). It's easy enough to grasp that with most software you need a complete image of the CD inside your computer, and then once the PQ codes have been added, which tell audio CD players where each track starts, the software simply transfers this complete image to a blank CD — and Bob's your uncle. However, anyone who read Mike Collins' comprehensive feature on Mac CD Mastering (May 96 issue), and his update, 'Disc‑O‑Tech' (March 1997 issue), will already know that with some software it can be a rigmarole setting these PQ codes. Often the only way of separating two tracks is by having a default two seconds of silence inserted between them. If you ever want to do something like cross‑fade between two tracks, this can often involve lots of workarounds, such as leaping in and out of different pieces of software.
Higher powered lasers capable of writing CDs are heavier, and cannot move as speedily as those in read‑only CD players, so 4‑speed playback is good going for a CD‑R.
Another extremely important area for CD‑R technology is that of data backup. Anyone who has ever had a hard disk crash, or a floppy disk retire to that great disk box in the sky will know that there is nothing more frustrating than losing data. Many businesses (and a few musicians) employ dedicated tape backup drives, using either computer DAT tapes or other proprietary tape‑cartridge media. Although these are well proven in the computer field (and, of course, the tapes can be re‑used time and time again), the main advantages of CD archives are their random access (no more waiting for an hour to scan the contents of an entire backup to access a single file), and their fixed nature (no more accidental wiping by someone who thought they were using a blank tape). Keeping regular backups on CD can also be far more secure than using any form of magnetic disk or tape, which can be affected by stray magnetic fields from unshielded loudspeakers and the like. The CD‑R must be top of the list for the musician archiving any form of data that's not likely to change, such as audio samples, or one‑off copies of albums.
The Teac CD‑R50S is supplied as a bare drive, ready for fitting into a standard PC 5.25‑inch drive bay (or into a Mac — see box). For about £60 more, you can get it in the CD‑R50SK (kit) version, which also has software for both PC and Mac (on a single dual‑format CD‑ROM) along with a PC floppy (holding additional drivers), audio and data cables and screws. It is a SCSI device, and although this means that you need a SCSI host adapter card inside your PC, bear in mind that a SCSI drive can also be connected to most samplers for accessing CD‑ROM libraries. The Adaptec AVA‑1505 card is often recommended for PC use, and will cost you about £45 (see my 'Drive Time' feature in the February issue for more details on choosing a SCSI card).
After connecting up the new drive, and checking that the default SCSI ID of 2 did not conflict with any other device in my system, I rebooted the PC with no problems, and the drive showed up correctly as an additional device in Windows 95. The first thing most people will do is to open and close the drive door, but I should warn you that it retracts rather smartly — make sure your fingers don't get in the way! Front‑panel controls include the normal eject button, 3.5mm headphone socket and thumbwheel volume control, and two LEDs that indicate power and busy. For pristine sampling, the Teac allows you to extract the digital data from audio CDs (not all drives do), and this is a definite plus point, although I didn't have an opportunity to check out this feature personally.
The drive has 4‑speed playback (600Kb/sec) when in use as a CD‑ROM player, which is not 'state‑of‑the‑art', but the higher‑powered lasers capable of writing CDs are heavier, and cannot move as speedily as those in read‑only CD players, so 4‑speed playback is good going for a CD‑R. The big plus is that the writing side is also 4‑speed, and this means that a typical hour‑long audio CD can be written in about 15 minutes — any faster and you would need a pretty expensive PC system to supply the data fast enough to ensure smooth operation. Most modern CD writers have a memory buffer to ensure that they can cope with brief hiccups in data flow, and the Teac comes with 1Mb, which is fairly standard on a drive of this calibre. To keep a steady flow of data when writing a CD at 4x speed (600Kb/second), a 1Mb buffer will cope with an interruption of 1Mb/600Kb, or 1.7 seconds. If your computer or hard drive cannot manage this, it's better to write at double speed to give everything more time to cope (up to 3.4 seconds interruption).
The supplied software for PC is CeQuadrat's WinOnCD v3.0 (see review later), and this comes on a dual‑format CD‑ROM, which also contains Toast CD‑ROM Pro v3.0 for Mac use. On the PC, running the install.exe file (which will happen automatically on loading the CD if you have 'auto‑insert notification' enabled) also prompts you to insert the supplied floppy disk with extra PC drivers (the Mac software is self‑ contained). Ironically, when you first run the WinOnCD software, the first thing it does is suggest that 'Auto‑insert notification' be switched off, and offers to do it for you. This is because otherwise the drive will periodically check to see if you have inserted a new CD, with potentially disastrous consequences if you're in the middle of burning your 74‑minute masterpiece! There are several options in the CD‑ROM section of Device Manager that need to be checked. The 'Disconnect' option must be on, because this controls whether the drive can disconnect itself from the SCSI buss while it is performing a lengthy operation, allowing another device to use the buss. The Sync option must be turned off as, although Synchronous data transfer is faster for normal purposes, the alternative Asynchronous transfer waits for an acknowledgement after each packet of data has been sent before sending any more, and this is vital; in normal use it's possible to retry after an error, but when writing a CD‑R it's better to be safe than sorry. Figure 1 (see page 216) shows the best settings to use.
Various other points need to be checked before you try burning your first CD. You first need to make sure that there are no programs that may kick in during the duration of the write process. Programs to disable include screen savers (likely to start up after several minutes of keyboard inactivity) and, in my case, the Power Management option that powers down my removable Syquest drive after 15 minutes with no drive activity. Even thermal calibration (periodic pauses by the disk drive to adjust for possible changes in temperature) can stop a drive for a second or more unless an AV type of drive is used. Any unintended interruption such as this may just be enough to cause the dreaded 'buffer underrun', which basically means that your CD has just turned into an attractive coaster for your coffee mug.
Preparing For The Big Moment
The supplied version of CeQuadrat's WinOnCD has a host of features, and is easy to use for most data applications, but for CD audio I did encounter some problems on the first run‑through. In the absence of a printed manual, I had a good read through the help file, with particular attention to the CD audio section. I assembled a single 650Mb WAV file in Sound Forge, containing seven tracks, adjusted the positions of all the track starts, and the length of silence between each track, even crossfading between two tracks. I then noted down all the exact start points and loaded the file into WinOnCD. No doubt most people will assemble a set of separate tracks, so that each start point requires no further editing, but with a composite file you select a portion of the waveform display, and then right‑click to bring up the Insert Track menu, so that you can point to the beginning of each track.
I expected to be able to zoom in, click on the desired start point, and insert a new track start, but the software insisted that I chose a section of any arbitrary length before it would accept the track, seemingly simply to extract the start point (this has been solved in the newer version of the software, and I'll enlarge on this later). However, despite the fact that I had perfect start points for each track noted down from Sound Forge, they kept adjusting themselves after I entered them into WinOnCD, putting the start points slightly after the beginning of the first note in the track. I finally worked out that because CDs are written in data blocks of 2532 bytes, track starts are forced to the start of the next block. Time Format can be changed from samples to milliseconds or blocks, so I switched to adjusting each start point by entering block points rather than invalid sample points, and this stopped them jumping to new positions. Once I'd worked all this out, the whole process was quick and fairly easy, but there was a lot of head scratching at first.
When I started to write my first audio CD, the software tried to create a new set of RAW files (totalling another 650Mb) as an image file. Since I didn't have a further 650Mb of space on my hard disk, I chose to write 'on the fly' from my existing file, and immediately received an error message. The problem was swiftly sorted out by Teac, and occurred because the review unit needed updating to the current firmware version, and I was soon up and running again. However, the error message prompted me to look in the troubleshooting section of the WinOnCD manual. This turned out to be telephone, fax or email contacts for CeQuadrat in Germany and the USA, and absolutely nothing else. There was no mention of error codes, let alone what to do if one appeared. CeQuadrat say that since any particular error message may be caused by many things, including other manufacturers' hardware, it's impossible to provide more meaningful printed assistance in this area. They also mentioned that image files are only really necessary when you're assembling CD‑ROMs with many small files and that an additional image file should not be needed for audio purposes, but it would have been useful if all of this had been mentioned in the disk manual/help file.
When writing my first audio CD, the Teac drive behaved impeccably. Even writing on the fly in 'Disc At Once' mode at quad speed, my P166+ PC produced not one glitch, and the CD was successfully written in 17 minutes. However, WinOnCD caused a strange anomaly during this process. The overall '% complete' indication was correct at the start of each track, but updated incorrectly during the track, with the result that after about 40 minutes worth of music data had been written the indication was permanently flashing 100% complete, returning to the correct value only at the beginning of each subsequent track. This does indicate sloppy Beta testing. When I finally listened to my CD, an extra two seconds had been inserted between each track. I was not a happy man!
Keeping regular backups on CD can be far more secure than using any form of magnetic disk or tape, which can be affected by other stray magnetic fields.
The latest version of WinOnCD (version 3.00.156) has a dialogue box that switches off forced pauses between tracks (you click on the ISRC button to open the dialogue!), and this version also allows you to simply click on the track start point to enter a new track, rather than selecting a portion of the waveform. Many small extra features (which are not yet documented in the helpfile) are also added. The software as originally supplied with the review Teac drive (version 3.00.145) is not as complete as this, so do check that you get the most up‑to‑date version. CeQuadrat's web site has driver updates, although you will need to download over 1Mb of zipped files.
Despite my initial troubles, and once I had the latest version of the software, WinOnCD v3.0 proved easy enough to use, especially for simple assembling of CD‑ROM discs. For audio use, it does a good basic job, and if you create your composite file in another application, such as Sound Forge, you can even crossfade between tracks. The WinOnCD help file/disk manual does need updating, but since this software retails elsewhere at £300, it's a bargain when bundled with the Teac CD‑R50S.
Going For The Burn
Once your data has been assembled ready for writing, it's simply a matter of clicking the right option, using whichever software is appropriate for your computer platform, and waiting for the burn to be completed. Thankfully, most software (including both packages supplied with the Teac drive) allows you to emulate a write procedure, so you can check that your system can cope at the selected speed. If problems do occur, simply lower the speed (4x, 2x and single speeds are available) until you get a successful emulation, and then retry. You only really need to do this once with a particular hardware setup, and it could save wasted blanks. The latest version of WinOnCD includes a separate utility called SpeedoMeter (see screenshot) which tests your system speed and recommends suitable maximum settings, independent of the actual CD‑R drive, giving you an idea of how much system power you have in hand.
Once I had sorted my problems with WinOnCD and was using the latest version it was all plain sailing. For Mac owners, the supplied Toast seems to be the best choice for ease of use (see the 'I'm Alright Mac' box). The CD‑R50S itself worked exactly as it should; the perfect CD writer is not exciting — it just gets on with the job reliably, and that's exactly what you want. I suspect that many studios may go for a 4‑speed writer, simply because a full album can be burned in about a quarter of its playing time — ideal if you need to quickly produce a one‑off copy for clients to take away with them — and if a 4‑speed device is what you're after, this is a good one which also works well as a CD audio player and CD‑ROM drive. What more can I say?
The basic measure of quality used by most commercial CD pressing plants is BLER (not the band, but BLock Error Rate). All CDs play back with some errors (and incorporate extra data and error correction to recover from these), but in the case of CD writers the number of errors gives an indication of drive quality, or bad or dirty media. Most modern drives, including the CD‑R50S, now have very low BLER levels. The problems with CDs burnt on one machine not playing back on another are largely caused by another phenomenon known as 'pit jitter' — the pits burned by the laser of the CD writer vary in length from 3 to 11 channel bits, known as 3T, 4T and so on. An ideal disc should have all pits of a particular value exactly the same length. Any variation is known as jitter. CD‑ROM drives differ in their ability to cope with a jittery signal, and this can cause problems with playing back CDs recorded with high levels of jitter on some other drives. Thankfully, the CD‑R50S has extremely low jitter levels. The final element to examine is that of the media itself. Although some manufacturers (notably Plasmon) design drives that can self‑calibrate to use any brand of media, most recommend specific types, since the laser power needed may vary from brand to brand. Teac recommend MTC (Mitsui), Kodak, TDK, TY, Mitsubishi, Ricoh, Hitachi, and Pioneer. This should be enough varieties for anyone!
There are several ways to approach the actual CD recording process. For CD‑ROMs, the easiest way is 'Track‑at‑once', which allows you to write each track separately, the big advantage being that you don't need a complete image of the full CD (which may be up to 650Mb) held on your hard drive. The disadvantage is that, for each track a run‑in and run‑out sector is written by the laser as it starts and stops writing. For data purposes this makes little difference, but if you're writing an audio CD it will play back as a slight 'click', and always produces two seconds of silence after each track, as well as causing errors at mastering houses if you try to use a disc written in this way to master audio CDs. Some earlier CD recorders permit only this mode, and this is why older CD‑R software adopts such an approach. To avoid the above problems, the 'Disc‑at‑once' mode should be used if available. This, as its name suggests, writes the whole disc in one go, and since the laser never stops during the procedure, no extra sectors are written. The result is a click‑free audio CD, and much more flexibility in the gaps between audio tracks. The WinOnCD software supplied with the CD‑R50S allows 'Disc‑at‑once' mode, and therefore can produce Red Book audio CDs (see 'All the Colours of the Rainbow' box for details of CD standards).
A third type is known as 'Session‑at‑once', and this was first introduced for PhotoCDs, since it allows you to add further data to an existing disc, until it is full. Each session creates a new directory, in addition to the newly added data, which links to the one previously written, and then writes an updated version (some software then writes a new directory containing entries for everything now on the disc; other software just creates a link so that the fragmented directories are all available). Once again, most audio CD players will only recognise the first session, and computer operating systems have assorted responses — MS‑DOS only sees the first session, Windows 95 sees only the last session.
I'M Alright Mac
Mac users will find a copy of Astarte's Toast CD‑ROM Pro v3.0 on the supplied CD‑ROM disc, and this provides the ability to record audio CDs or back up hard disk data. This is probably the best choice of basic software as far as ease of use is concerned, though you do have to import songs as separate audio files in order to add the necessary track timing information. As a CD compilation tool, Toast CD‑ROM Pro is fine for routine jobs, but it precludes any fancy editing or the inserting of indexes in the middle of files. Digidesign's Masterlist CD, on the other hand, enables Sound Designer II users to convert markers into track indexes, but I was unable to get Masterlist CD to even recognise this drive. A call to Digidesign confirmed that, as yet, the Teac CD‑R50S is not on their list of approved drives, so if you specifically need to use Masterlist CD, you'll have to find a drive that's on their list.
Since SCSI devices are standard whatever the computer platform, the actual installation of the hardware is identical in Mac and PC, although the Mac version of Toast doesn't need a separate driver floppy. No copy protection is involved as far as Toast is concerned, but you do have to enter your personal details and serial number before the program will run first time around.
Installation on my old Mac Centris 650 was uneventful, and using the software seemed very straightforward. On running the speed test, it was confirmed that my combination of computer and ageing IBM hard drive would record quite happily at twice normal speed, but couldn't manage quad speed. Paul White
All The Colours Of The Rainbow
When you first start thinking about CD‑R, the onslaught of specifications can be overwhelming. Each CD format has its standard technical specification, but it helps to put them into historical perspective.
- Red Book (CD‑DA): This is the original spec agreed in 1982, and is for audio CDs (also known as CD‑DA). For most musicians, Red Book is still the most important.
- Yellow Book (CD‑ROM): In 1984, the data version of CD was introduced, but it was not ideal for the emerging multimedia market, who wanted the standard extended for audio and video.
- Green Book (CD‑I): The extended Yellow Book version was agreed in 1987, and Compact Disc Interactive players subsequently appeared.
- Orange Book (CD‑R): The Kodak Photo CD was the first to use 'write‑once' technology, as well as allowing multiple sessions, so that more data could be added at later dates. In 1990, the definitions were laid down in the Orange Book, and are widely used for backing up data. In 1995, the new CD‑E (Erasable) discs were incorporated into version 3 of this standard.
- White Book (VideoCD): The White Book standard, for storing up to 70 minutes of video, was first defined in 1993, but was updated to version 2 in 1994, to make it more suitable for interactive video applications, rather than just linear video.
- Blue Book (CD Extra, also known as CD plus): This is a two‑session CD, such as those found cover‑mounted on some magazines. The first session is CD‑DA, and the second is data. It was standardised in 1996, and resolved the problems caused on some CD players when playing audio tracks. The new format is primarily an audio one, but allows any extra space on the CD to be used by interactive multimedia programs.
- Rainbow: Many CD‑ROMs were produced with several areas, suitable for multiple platforms such as PC and Mac (and known as Hybrid CDs). The data track of such Hybrid CDs can also be packed on a CD‑Extra disc. If additional CD‑i data is placed on a CD‑Extra, the disc can also be played back by audio CD players, PCs, Apple Macintosh computers, and CD‑i players. This special kind of CD‑Extra is called Rainbow CD.
- 4‑speed CD writing is as fast as they come.
- Low processor overhead when used as 4‑speed CD‑ROM drive.
- Good quality audio CD player.
- Incomplete WinOnCD help file.
- No fault‑finding guidance in WinOnCD documentation.
The CD‑R50S is a good all‑round drive, not just a CD writer. If you need to write more than a few CDs, its 4‑speed operation will save a lot of time. The combined WinOnCD 3.0/Toast CD‑ROM Pro 3.0 software for both platforms works out at only £60 more when bought with the kit version, and so is excellent value.