What's CD-R? CD-RW? CD-R is short for "CD-Recordable". Recordable CDs are WORM (Write Once, Read Multiple) media that work just like standard CDs. The advantage of CD-R over other types of optical media is that you can use the discs with a standard CD player. The disadvantage is that you can't reuse a disc. A related technology called CD-Rewritable (CD-RW) allows you to erase discs and reuse them, but the CD-RW media doesn't work in all players. CD-Rewritable drives are able to write both CD-R and CD-RW discs. All CD recorders can read CDs and CD-ROMs, just like a standard CD-ROM drive.
Are they identical to normal CDs? The CDs you buy in a store are pressed from a mold. CD-Rs are burned with a laser. They may look different (often green, gold, or blue instead of silver), they're less tolerant of extreme temperatures and sunlight, and they're more susceptible to physical damage. Whether CD-Rs or pressed CDs last longer is difficult to answer. While they're not physically identical, they work just the same. Some CD players and CD-ROM drives aren't as good at reading CD-R and CD-RW discs as they are at reading pressed CDs, but by and large they work just fine. By the way, you can't record on pressed discs, so you might as well throw out all those AOL CD-ROMs you've been accumulating. Buying a bunch of old CDs in the hopes of writing new stuff onto them is a bad idea. You have to buy blank CD-R or CD-RW media.
Can I create new audio and data CDs? Yes. You can create CD-ROMs from data on your hard drive, and you can create new audio CDs from anything you can record into a WAV or AIFF sound file. With an audio-only CD-Recorder, which hooks up to your stereo system instead of your computer, you can record directly from CD, cassette, DAT, or whatever. The CD-ROMs you produce will play in ordinary CD-ROM drives, and the audio CDs you create will work in your home or car CD player. Writing to CD-Rs and CD-RWs requires a special drive. You can't write CDs with an ordinary CD-ROM drive.
Can I use it to copy my CDs? Yes, both audio and data CDs can be duplicated. You can even create audio CDs that are compilations of other audio CDs (perhaps a personal "best of" disc). Bear in mind that most CDs are protected by copyright laws.
How much can they hold? About 74 minutes of audio, or about 650MB of data. Some CD-R blanks can hold 80 minutes of audio, or about 700MB of data
Can I just copy files onto a CD-R like I would to a floppy? Yes and no. The process can be a bit more involved than that, and requires special software that (usually) comes bundled with the drive. With "packet writing" software, and a recorder that supports it, you can treat a CD-R or CD-RW disc like a floppy. Generally speaking, you can only write to each part of the disc once, so deleting files doesn't gain any space. There are other limitations as well. With more traditional software -- necessary if you want the broadest possible compatibility -- you usually end up writing everything to the disc all at once. When you're doing the writing you can't interrupt the drive, and you can't reclaim the space you've used. If you want to write your files in smaller bunches, you lose a fair bit of space every time you stop and start again.
Can I copy DVDs with a CD recorder? Not directly. CD and DVD are very different formats, so you can't write DVDs with your CD recorder. You may be able to convert the contents into a lower-quality format though.
How long does it take to burn a CD-R? It depends on how much data you're going to burn, and how fast your drive is. Burning 650MB of data takes about 74 minutes at 1x, 37 minutes at 2x, and 19 minutes at 4x, but you have to add a minute or two for "finalizing" the disc. Remember that single speed is 150KB/sec, double speed is 300KB/sec, and so on. If you have half the data, it will finish in (about) half the time
If recording fails, is the disc usable? That depends on what was being recorded, how it was being recorded, and how far along in the process things were. If it failed while writing the lead-in, before any data was written, the disc probably isn't usable. Some drives, notably certain Sony models, have a "repair disc" option that forcefully closes the current session. This would allow you to add extra data in a second session on the disc, but anything written in the first session will be unavailable. Failures when finalizing the disc may be correctable. Sometimes the TOC gets written before the failure, and the disc can be used as-is. Sometimes you can use a "finalize disc" option from a program menu that will do the trick. Other times the recorder will refuse to deal with a partially-finalized disc, and you're stuck. Failures in the middle of writing result in a CD-ROM that probably isn't worth trusting. Some of the data will be there, some won't. The directory for the disc may show more files than are actually present, and you won't know which are actually there until you try to read them. Audio CDs recorded in disc-at-once mode are a special case. Because the TOC is written up front, the disc is readable in a standard CD player even if the write process doesn't finish. You will be able to play the tracks up to the point where the recording failed. If you were using a packet writing program like DirectCD, the experiences of people on Usenet suggest that you are either 100% okay or 100% screwed. The ScanDisk utility included with DirectCD 2.5 may help though
How do I erase or format a disc? If you're using CD-R media, and you're not using a packet writing program like DirectCD, you can stop reading now. You don't need to prepare CD-R discs for conventional recording, and you can't erase them no matter how hard you try. (Note for the nit-pickers: "erase" means removing the data so that the disc can be re-used. Procedures involving microwave ovens and belt sanders don't qualify.).If you want to erase a CD-RW disc, use the software that came with your CD-ReWritable drive. Somewhere in the army of applications and mountain of menus is the command you're looking for. If you're going to be using packet writing, a little formatting will be necessary. The application should offer to do this automatically the first time you insert a blank disc. The fixed-packet formatting that DirectCD does for CD-RW discs takes about 50 minutes on a 2x rewritable drive. The difference between "erase" and "quick erase" is that the former erases the entire disc, while the latter just stomps on the Table of Contents (TOC). It's like erasing the directory off of a floppy disk. The file data is still there, but since there's nothing pointing to it, the disc appears empty. (Some people have asked if it's possible to recover data from a quick-erased disc. The general answer is, "don't count on it".)The difference between "format" and "fast format" (such as is offered on the HP8100/Sony CRX100) is of a different nature. Both format the entire disc, and both operate at the same speed, but the "fast" format allows you to use the drive before formatting has completed. After a few minutes, you are allowed to access the drive while the formatting process continues in the background. Incidentally, most conventional (pre-mastering) software will refuse to record on a disc that has been formatted for packet writing. In some cases the error message may be a confusing remark that insists the disc isn't writ able.
Can I record an audio CD a few tracks at a time? That depends on what you're trying to accomplish. There are two issues that complicate matters:
Some people have CD players that will play songs from every session. If you do, and compatibility with other players isn't important, you can write each group of tracks into its own session. The down side of this approach is that there is an appreciable amount of overhead when opening a new session (23MB for the first and 14MB for each additional one). If your hard drive has enough space, you can just keep the WAV files on the drive, and burn the disc all at once. If it doesn't, you can write the tracks to a CD-R or CD-RW disc as WAV files on CD-ROM, and record from there. Write a new CD-R or CD-RW every time you get more tracks. (The advantage to using CD-ROM is that additional error correction is used.)
Is it better to record at slower speeds? It depends on your recorder, media, and who you talk to. For example, some informal testing with the venerable Yamaha CDR-100 determined that it worked best at 4x speed with media certified for 4x writes. 1x worked almost as well, but 2x would occasionally produce discs with unrecoverable errors. With audio CDs, the results are more subjective. Some people have asserted that you should always write at 1x, others have stated that 2x may actually be better. It depends on the recorder, media, player, and your ears. Try it both ways and listen. CD-R media is written by heating up tiny sections of the disc. When the disc spins faster, the laser has less time to shine on a particular spot, so the laser has to be controlled differently. Different formulations of media may require a different "write strategy" at certain speeds, and each recorder may adjust its write strategy differently to accommodate those speeds. This can potentially result in combinations of recorder and media that work perfectly at one speed but fail miserably at another. Put simply, there's more to writing at high speed than just spinning faster. There is no One True Answer to this question. Do what works best for you.
Can CD-Rs recorded at 2x be read faster than 2x? Of course. The only possible basis in fact for the, "if it was recorded at 2x, you can't read it faster than 2x" rumors is that some drives have trouble reading CD-R media. Discs that are hard to read when spinning at 12x may become easier to read when spinning at 4x. It has also been noted that some recorders will write more legible discs at certain speeds (e.g. the Yamaha CDR-100, which works better at 1x or 4x than it does at 2x). None of this should lead anyone to conclude, however, that the write speed and read speed are tied directly together. The reader, writer, and media all have a role in determining how quickly a CD-R can spin and be readable. It's also the case that discs written at high speed (say 8x) can be read by drives *slower* than 8x. So if you're distributing discs to people with old 4x CD-ROM drives, you don't have to worry about them not being able to read at 8x. Of course, if the CD-ROM is poorly constructed, or the writer is producing marginal discs at high speeds, you might see evidence to the contrary, but there is no technical barrier to reading discs recorded at 8x or 12x on a slower drive.
Do I need to worry about viruses? Absolutely. Infected CD-ROMs are every bit as nasty as infected floppies, if not worse: you can't disinfect the source media. It is prudent to scan your files before creating a CD-ROM for distribution, and it's not a bad idea to scan the CD-ROM afterward (in case somebody has cleverly infected your CD writing software). The dangers of boot sector viruses on bootable CD-ROMs are probably low. Because the boot sector is created directly by the recording software, and can't be modified after it has been written, the opportunity for infection is small.
How do I clean my CD recorder? In general, you don't. The only reason you'd need to clean a recorder or (for that matter) a CD-ROM drive is if you went and stuck your finger on the lens. Cleaning kits and well-intentioned Q-tips are unnecessary and potentially dangerous. If you have an overwhelming desire to clear the dust out of your recorder, and can't or don't want to send it to a service center, use gentle(!) bursts of compressed air. [ I've never had to clean a lens in *any* CD player, including a flip-up top-loading boom box that I've had since mid-1990. I can *see* the dust inside, and I can see the lens, but it has no problem playing discs. I can't imagine how a recorder that's only a year or two old is going to collect enough dust to fail. ]
How do I put photographs onto CD-ROM? The first thing you have to do is get them onto your computer. There are three basic approaches: use a scanner to convert printed photographs, use a video digitizer to pull images off of a video tape, or use a digital camera to take pictures that can be transferred directly. Once you have the photograph on your hard drive, you may want to touch it up a bit. You can use software to correct for over- and under-exposed snapshots, remove "red eye", and crop off bits that weren't supposed to be in the frame. Cameras and scanners should come with image manipulation software that will help you manipulate and manage the image. Once you've got the images in a reasonable state, save them in a widely accepted format such as JPEG or TIFF, and write them to a CD-ROM like you would any other files. You may need to use an "Export" function rather than "Save As...", because consumer photo software authors tend to use proprietary image formats as the default.
THERE ARE MANY QUESTIONS THAT I HAVE NOT ANSWERED ON THIS PAGE. I SUGGEST THAT YOU TAKE THE TIME TO READ THE MANUAL THAT CAME WITH YOUR CD-RECORDER. MOST OF YOUR QUESTIONS WILL BE ANSWERED IN THERE. IF YOU CAN NOT FIND THE ANSWER TO YOUR QUESTION PLEASE EMAIL ME AND I WILL DO MY BEST TO ANSWER YOUR QUESTION. |
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