From - Mon Sep 15 07:21:13 1997 Newsgroups: comp.publish.cdrom.hardware,comp.publish.cdrom.software,comp.publish.cdrom.multimedia,comp.answers,news.answers Path: news.mitre.org!blanket.mitre.org!agate!newsgate.cuhk.edu.hk!logbridge.uoregon.edu!feed1.news.erols.com!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!ix.netcom.com!fadden From: fadden@netcom.com (Andy McFadden) Subject: [comp.publish.cdrom] CD-Recordable FAQ, Part 1/2 Message-ID: Followup-To: comp.publish.cdrom.hardware Summary: Frequently Asked Questions about CD recorders, CD-R media, and CD premastering. Sender: fadden@netcom4.netcom.com Supersedes: Organization: Lipless Rattling Crankbait Date: Sun, 14 Sep 1997 20:54:00 GMT Approved: news-answers-request@MIT.EDU Lines: 2361 Xref: news.mitre.org comp.publish.cdrom.hardware:44688 comp.publish.cdrom.software:22028 comp.publish.cdrom.multimedia:13505 comp.answers:27507 news.answers:109783 Archive-name: cdrom/cd-recordable/part1 Posting-Frequency: monthly Last-modified: 1997/09/14 Version: 1.11 Send corrections and updates to Andy McFadden (fadden@netcom.com). If you have a question you'd like to see answered in here, either post it to one of the comp.publish.cdrom newsgroups (if you don't have the answer), or send it to fadden@netcom.com (if you do). If you're reading this on a web page and want to check out the newsgroups (which have maintained a moderate signal-to-noise ratio), see: news:comp.publish.cdrom.hardware news:comp.publish.cdrom.software news:comp.publish.cdrom.multimedia The HTML form of this FAQ is available from the CD Information Center: http://www.cd-info.com/CDIC/Technology/CD-R/FAQ.html The text version of this FAQ is available from: ftp://rtfm.mit.edu/pub/usenet-by-group/comp.publish.cdrom.hardware/ An automatic text-to-HTML conversion can be found here: http://www.faqs.org/faqs/cdrom/cd-recordable/part1/preamble.html If the news posting appears to be cut off at the bottom, and you read news with a browser like Netscape Navigator, you may need to increase a buffer size. Please DO NOT post copies of the HTML version on your web site. I keep getting e-mail from people reading versions that are several months old. You should include a link to the www.cd-info.com site instead. Contents ======== [0] Introduction [0-1] Legal noise (disclaimers and copyrights) [0-2] What does this FAQ cover? [0-3] What's new since last time [0-4] Appropriate use of the newsgroups [1] Basics [1-1] What's CD-R? [1-2] Are they identical to normal CDs? [1-3] Can I use it to copy my CDs? [1-4] How much can they hold? [1-5] Can I just copy files onto a CD-R like I would to a floppy? [2] CD Encoding [2-1] How is the information physically stored? [2-2] What is XA? CDPLUS? CD-i? MODE1 vs MODE2? Red/yellow/blue book? [2-3] How do I know what format a disc is in? [2-4] How does CDROM copy protection work? [2-5] What's a multisession disc? [2-6] What are subcode channels? [2-7] Are the CD Identifier fields widely used? [2-8] How long does it take to burn a CD-R? [2-9] What's the difference between disc-at-once and track-at-once? [2-10] Differences between recording from an image and on-the-fly? [2-11] How does an audio CD player know to skip data tracks? [2-12] How does CD-E/CD-RW compare to CD-R? [2-13] Can DVD drives read CD-Rs? [2-14] Should I wait for DVD-R? [2-15] What are "jitter" and "jitter correction"? [2-16] Where can I learn more about the history of CD and CD-R? [3] How Do I... [3-1] How do I copy a data CD? [3-1-1] Why can't I just do a block copy like a floppy? [3-2] How do I extract tracks from, or copy all of, an audio CD? [3-3] How do I avoid clicks on audio CDs? [3-4] How do I copy Sony Playstation, Sega Saturn, or 3DO discs? [3-5] How do I get long filenames onto a disc? [3-5-1] ISO-9660 [3-5-2] Rock Ridge [3-5-3] HFS [3-5-4] Joliet [3-5-5] Romeo [3-5-6] ISO/IEC 13346 and ISO/IEC 13490 [3-6] How do I use a CD-i disc on a PC? [3-7] How can I extract disc and track titles from an audio CD? [3-8] How do I copy an 80-minute CD? [3-9] How do I create a PhotoCD? [3-10] How do I make a CD that will work on a PC or a Mac? [3-11] How do I get at different sessions on a multi-session CD? [3-12] How do I transfer my records or cassettes to a CD? [3-13] How do I transfer an audio DAT tape to CD? [3-14] How do I put audio and data on the same CD? [3-15] How do I make a bootable CD? [3-16] How do I convert home videos into video on CD? [3-17] How can I burn several copies of the same disc simultaneously? [3-18] Can I make copies of copies? [3-19] How can I compress or encrypt data on a CD? [3-20] Can I do backups onto CD-R? [3-21] How do I change the CD icon? How does Win95 autoplay work? [3-22] How can I be sure the data got written correctly? [3-23] How do I copy Karaoke/CD+G discs? [3-24] How do I copy a CDROM with 3GB of data on it? [3-25] How do I get my CD-R pressed into a real CD? [3-26] How do I make a "concert" CD-R, with tracks but no gaps? [4] Problems [4-1] What does "buffer underrun" mean? [4-2] I can't get long Win95 filenames to work right [4-3] I can't read the multisession CD I just made [4-4] Write process keeps failing N minutes in [4-5] Why did my CD-R eject between the "test" and "write" passes? [4-6] My CDROM drive doesn't like *any* CD-R discs [4-7] How do I avoid having a ";1" on my ISO-9660 discs? [4-8] I keep getting SCSI timeout errors [4-9] I'm having trouble writing a complete disc [4-10] I get a Write Append Error when the burn is nearly done [4-11] Getting errors reading the first (data) track on mixed-mode CD [4-12] My CD-R ejects blank discs immediately [4-13] I'm getting complaints about power calibration [4-14] My Adaptec 2940 pauses after finding my CD-R [4-15] I can't see all the files on the CD-R [4-16] I forgot to use "linked" multisession on my last write [4-17] I'm getting SCSI errors or corrupted data [4-18] Why doesn't the copy of an audio CD sound the same? [4-18-1] Why doesn't the audio data on the copy match the original? [4-18-2] The audio data matches exactly, why do they sound different? [4-19] Digital audio extraction of a track is slightly off [5] Hardware [5-1] Which CD-R unit should I buy? [5-1-1] Yamaha [5-1-2] Sony [5-1-3] Smart & Friendly [5-1-4] Philips [5-1-5] HP [5-1-6] Plasmon [5-1-7] Kodak [5-1-8] JVC [5-1-9] Pinnacle [5-1-10] Ricoh [5-1-11] Pioneer [5-1-12] Olympus [5-1-13] Optima [5-1-14] Mitsumi [5-1-15] DynaTek Automation Systems [5-1-16] Microboards of America [5-1-17] Micro Design International [5-1-18] MicroNet Technology [5-1-19] Procom Technology [5-1-20] Grundig [5-1-21] Plextor [5-1-22] Panasonic [5-1-23] Teac [5-1-24] Wearnes [5-1-25] Turtle Beach [5-1-26] Creative Labs [5-1-27] Taiyo Yuden [5-1-28] Memorex [5-1-29] Hi-Val [5-2] How long do CD-R drives last? [5-3] What kind of PC is recommended? [5-4] What kind of Mac is recommended? [5-5] Which standard CDROM drives work well with CD-R? [5-6] What kind of HD should I use with CD-R? Must it be AV-rated? [5-7] What kind of SCSI adapter should I use with CD-R? [5-8] Can I use a CD-R as a general-purpose reader? [5-9] To caddy or not to caddy? [5-10] Can I burn CDs from a Jaz drive? Tape drive? [5-11] What is "Running OPC"? [5-12] What's the story with audio CD-Rs? [5-13] How do I tell what version of firmware I have? [5-14] How well do ATAPI (IDE) and parallel-port CD-Rs work? [6] Software [6-1] Which software should I use? [6-1-1] Adaptec - Easy-CD, Easy-CD Pro, and Easy-CD Pro MM [6-1-2] Adaptec - CD-Creator [6-1-3] Elektroson - GEAR [6-1-4] Adaptec - Toast CD-ROM Pro [6-1-5] CeQuadrat - WinOnCD [6-1-6] Young Minds, Inc. - SimpliCD [6-1-7] Golden Hawk Technology (Jeff Arnold) - CDRWIN [6-1-8] Optical Media International - QuickTOPiX CD [6-1-9] Creative Digital Research - CDR Publisher [6-1-10] mkisofs [6-1-11] Asimware Innovations - MasterISO [6-1-12] Newtech Infosystems, Inc. (NTI) - CD-Maker and CD-Copy [6-1-13] Cirrus Technology - CDMaker [6-1-14] Hohner Midia - Red Roaster [6-1-15] Dataware Technologies - CD Author [6-1-16] CreamWare - Triple DAT [6-1-17] MicroTech - MasterMaker [6-1-18] Angela Schmidt & Patrick Ohly - MakeCD [6-1-19] Optical Media International - Audiotracer [6-1-20] Jörg Schilling - CD Record [6-1-21] Prassi Software - CD Rep [6-1-22] Nero Software - SubIgnition [6-1-23] Dieter Baron and Armin Obersteiner - CD Tools [6-1-24] PoINT - CDwrite [6-1-25] PoINT - CDaudio Plus [6-1-26] Adaptec - Easy CD Creator [6-1-27] Padus - DiscJuggler [6-1-28] Ahead Software - Nero [6-1-29] CharisMac Engineering - Discribe [6-1-30] István Dósa - DFY$VMSCD [6-1-31] RSJ Software - RSJ CD Writer [6-1-32] James Pearson - mkhybrid [6-2] What other useful software is there? [6-2-1] Optical Media International - Disc-to-Disk [6-2-2] Gilles Vollant - WinImage [6-2-3] Asimware Innovations - AsimCDFS [6-2-4] Steven Grimm - WorkMan [6-2-5] Adaptec - Easy-CD Backup [6-2-6] Cyberdyne Software - CD Worx [6-3] What is packet writing software? [6-3-1] Adaptec - DirectCD [6-3-2] CeQuadrat - PacketCD [6-3-3] SmartStorage - SmartCD for Recording95 [6-4] I want to write my own CD-R software [6-4-1] PoINT - CDarchive SDK [6-4-2] Golden Hawk Technology (Jeff Arnold) [7] Media [7-1] What kinds of media are there? [7-2] Does the media matter? [7-3] Who manufactures CD-R media? [7-4] Which kind should I use? [7-5] How long do CD-Rs last? [7-6] How much data can they hold? [7-7] Is it okay to write on or stick a label on a disc? [7-8] How do CD-Rs behave when microwaved? [7-9] What can I do with CD-R discs that failed during writing? [8] Net Resources and vendor info [8-1] Information resources [8-2] Magazines and other publications [8-3] Net.vendors [9] Contributors ------------------------------------------------------------------------------ Subject: [0] Introduction Subject: [0-1] Legal noise (disclaimers and copyrights) Free distribution of the plain ASCII text form of this FAQ is encouraged, as are conversions to HTML or other formats and translation to foreign languages, so long as no content is removed, and additions are clearly marked. Redistribution of the HTML form of this FAQ or other format conversions may be restricted (the content is free, the presentation might not be). Check with the publisher. Caveat lector: the information here is derived from Usenet postings, e-mail, and information on WWW sites. As such, it may well be DEAD WRONG, and you are encouraged to verify it for yourself. I take no responsibility for damaged hardware, CD-Rs turned into coasters or frisbees, time lost, or any other damages you incur as a result of reading this FAQ. Information on specific models of hardware and software is based on *opinions* of other users, not scientific studies. I am not an expert in this (or any other) field. Everything here could be a total malicious lie, and should be treated as such. You have been warned. I don't get paid to plug anybody's software or equipment. The sections on "what XXX should I buy" are not here because I want to sway purchases one way or another, they're here because the questions are asked *a lot*, and the answers are pretty consistent. You are invited and encouraged to investigate the capabilities and reputations of all products. The various product and company names are trademarks of their respective companies. Subject: [0-2] What does this FAQ cover? This document attempts to answer Frequently Asked Questions about CD-Recordable technology and related fields. It is a Usenet newsgroup FAQ, updated and posted around the middle of each month. The main foci are explaining CD-R technology, describing hardware and software solutions for creating audio CDs and CDROMs, and helping people find solutions to common problems. The FAQ is heavily biased toward PCs and computer CD-Rs, because that's what I'm most familiar with, but I have made an effort to include useful information for owners of other equipment. I don't anticipate the section on audio CD-Rs expanding greatly, because they're far simpler to operate than computer CD-Rs, and most of the "must know" information about them is more appropriate in an FAQ on stereo systems or studio recording. I don't usually address questions that can be phrased, "how do I make my software do this?" The answers to those should be in the manual that came with your software. I also don't try to track recorder firmware versions or software versions unless a specific release is especially interesting. Ditto for which recorders work with which packet-writing solutions. Subject: [0-3] What's new since last time Kind of a quiet month. Added (2-16), (3-26), (5-14), (6-1-31), (6-1-32), (6-3-2), and (6-3-3). Subject: [0-4] Appropriate use of the newsgroups This FAQ covers the three newsgroups in the comp.publish.cdrom hierarchy, one for software, one for hardware, and one for multimedia. The names of the newsgroups imply that the intended topics are related to publishing material on CDROMs, but the current discussions cover most everything related to CD-Recordable devices. Here are a few guidelines. These aren't hard and fast rules -- nobody died and put me in charge of making the rules -- but if you're not sure what the appropriate subject matter is then this may be helpful. news:comp.publish.cdrom.hardware is the most popular of the groups. Appropriate material includes questions about past, current, and future CD-R devices. Asking for installation help or advice on what to buy is appropriate, as are questions about related hardware like SCSI adapters and CDROM drives. Some related newgroups are: news:comp.sys.ibm.pc.hardware.cd-rom news:comp.sys.ibm.pc.hardware.storage news:comp.sys.ibm.pc.hardware.systems news:comp.periphs.scsi news:alt.cd-rom news:alt.comp.periphs.cdr news:linux.apps.cdwrite news:comp.publish.cdrom.software is for discussions about software used to prepare material for and create CDs and CDROMs. Questions about how to do things with a specific piece of software belong here, as do "the CD-R software from XXX won't recognize my drive", and "does a program exist that does YYY". Some related newsgroups are: news:alt.cd-rom news:linux.apps.cdwrite news:comp.publish.cdrom.multimedia is for discussions about creating multimedia products on CDROMs. Questions about multimedia authoring software belong here, as do most production-type questions, e.g. "where can I go to get my CD pressed with jewel cases and glossy inserts?" Related newsgroups are: news:comp.multimedia news:rec.video.desktop news:rec.video.professional news:rec.photo.digital news:misc.education.multimedia Please try to keep cross-posting to a minimum. Broadcasting questions to 3 or 4 related newsgroups will increase the noise level and probably won't get you more answers. Some general rules apply to all of the comp.publish.cdrom.* groups: (1) Piracy of CD-R software or CDs: CD-Rs can be used to make copies of copyrighted material, and while backups of data are legal, making or accepting copies from others most likely isn't. Whatever your opinion of the matter, software piracy and other copyright violations are illegal in most countries in the world, so requests and/or advertisements for pirated material should be kept off the newsgroup. Also, please don't start or participate in a debate about whether or not software piracy is bad. There have been hundreds of such debates over the past several years, and the only thing that either side has managed to prove is that piracy debates are a tremendous waste of time. (2) Personal CD-R hardware and software sales: strictly speaking, these groups aren't appropriate for selling off your old hardware or software. Such things are best left in misc.forsale.computers.*, ba.market.computers, and related groups. Since many readers are in the market for new hardware, a limited number of clearly marked articles are tolerated. The common Usenet convention is to use "FS: HP4020i $400 obo" for "For Sale" messages and "WTB: HP4020i" for "Want To Buy" messages. (3) CD-R product advertising: these groups by their nature are somewhat commercial. Many readers are in the market for new hardware or CD-R media, and for this reason a *limited* amount of retail/wholesale advertising is tolerated but discouraged. If you *clearly* mark your postings as advertisements, you will get relatively few complaints. Posting frequent and useless followups just to broadcast your 20-line signature will get you flamed and subsequently ignored. Feel free to send mail to people who post questions about product pricing and availability, but please don't create mailing lists and broadcast to everyone who posts. (4) Other advertising: while it's certainly the case that most or all of the readers have a CDROM drive on a computer, the same could be said of almost every person reading news from a home computer today. Please keep ads in newsgroups that are more appropriate. Advertising the latest educational, game, or adult CD is inappropriate for these groups, as are "hot new Cyrix 686 PC" posts. Subtle attempts to advertise web sites ("golly, this looked really neat, so I thought I'd tell everyone") are more obvious than you might think. (5) Spam: you cannot make money fast. That's life, get used to it. If the message involves putting your name at the top of a list of 5 or 10 people, don't post it. If it has an 800 or 888 number that a reader would call to hear more about your unique business opportunity, don't post it. If you have an account at interramp.com, your posts may get ignored. (6) Job postings: looking for job candidates on these newsgroups is a tolerated but generally futile exercise. Most of the readers are looking for or offering help on CD-Rs, not searching for a job. Try one of the other groups, like misc.jobs.offered. One final note: bear in mind that these groups are read by people all over the world. If you're looking for local retailers, be sure to specify what "local" is for you. Posting in English is the best way to ensure that you will get a response, but the readership is diverse enough that you will likely get a reply no matter what language you use. If you want to quote prices, specify the currency to avoid confusion (e.g. US$300 or CAN$300 or Y30000 or ...). ------------------------------------------------------------------------------ Subject: [1] Basics These are intended to be brief (if somewhat incomplete) answers to basic questions. More detailed information can be found later in the FAQ. Subject: [1-1] What's CD-R? 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 (a/k/a CD-E or CD Erasable) is expected to be available in 1997. These discs will work like CD-Rs, but will be erasable as well. Subject: [1-2] 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 look different (green, gold, or blue instead of silver), they're less tolerant of extreme temperatures and sunlight, and don't last as long. (But they still last a very long time.) Subject: [1-3] Can I use it to copy my CDs? Yes, both audio and data CDs can be duplicated. Bear in mind that most CDs are protected by copyright laws. You are allowed to make an archival backup of software, but the same doesn't necessarily hold true for music. http://www.brouhaha.com/~eric/bad_laws/dat_tax.html has some relevant information and pointers. Subject: [1-4] How much can they hold? About 74 minutes of audio, which is about 650MB of data. Subject: [1-5] Can I just copy files onto a CD-R like I would to a floppy? Yes and no. The process is usually a bit more involved than that, and requires special software that (usually) comes bundled with the drive. You don't need to write everything all at once, but when you're doing the writing you can't interrupt the drive, and you can't reclaim the space you've used. A certain amount of space is lost every time you stop and start again. Newer "packet writing" software and CD-RW (rewritable) drives let you do this more easily, but the discs created may be unreadable by other systems. ------------------------------------------------------------------------------ Subject: [2] CD Encoding CD fundamentals. Subject: [2-1] How is the information physically stored? From _The Compact Disc Handbook, 2nd edition_ by Ken Pohlmann, 1992 (ISBN 0-89579-300-8): "Write-once media is manufactured similarly to conventional playback-only discs. As with regular CDs, they employ a polycarbonate substrate, a reflective layer, and a protective top layer. Sandwiched between the substrate and reflective layer, however, is a recording layer composed of an organic dye. .... Unlike regular CDs, a pre-grooved spiral track is used to guide the recording laser along the spiral track; this greatly simplifies recorder hardware design and ensures disc compatibility." A laser in the CD recorder creates a series of holes in the disc's dye layer called "pits". The spaces between the pits are called "lands". The pattern of pits and lands on the disc encodes the information and allows it to be retrieved on an audio or computer CD player. The sprial makes 22,188 revolutions around the CD, with roughly 600 track revolutions per millimeter as you move outward. If you "unwound" the spiral, it would be about 3.5 miles long. See the net references section for pointers to more data (especially http://www.cd-info.com/). http://www.araltd.com/whatscdr.html has some nice pictures. Subject: [2-2] What is XA? CDPLUS? CD-i? MODE1 vs MODE2? Red/yellow/blue book? See the net references section for pointers. The "information" frame in http://www.cdarchive.com/info/default.htm has useful data, as does http://www.cd-info.com/ and the alt.cd-rom FAQ pages. The page http://emf.net/~mal/cdplus.html is dedicated to CD Extra. A quick summary of standards: Red Book = physical format for audio CDs (a/k/a CD-DA) Yellow Book = physical format for data CDs Green Book = physical format for CD-i Orange Book = physical format for recordable CDs Part I = CD-MO (Magneto-Optical) Part II = CD-WO (Write-Once; includes "hybrid" spec for PhotoCD) Part III = CD-RW (ReWritable) White Book = format for VideoCD Blue Book = CD Extra (occasionally used to refer to LaserDisc format) CD Extra = a two-session CD, 1st is CD-DA, 2nd is data (a/k/a CD Plus) CDROM/XA = eXtended Architecture, a bridge between Yellow Book and CD-i MODE-1 = standard Yellow Book sectors MODE-2 = may be of form-1 or form-2 FORM-1 = 2048 bytes of data, with error correction, for data FORM-2 = 2324 bytes of data, no ecc, for audio/video ISO 9660 = file layout standard (formerly called High Sierra) Rock Ridge = extensions allowing UNIX stuff like long filenames and symlinks CD-RFS = Sony's incremental packet-writing filesystem CD-UDF = industry-standard incremental packet-writing filesystem CD-Text = Philips' standard for encoding disc and track data on audio CDs In case the above seems straightforward, Yellow Book actually defines both mode 1 and mode 2, where mode 2 contains 2336 user data bytes. Green Book defines mode 2 form 1 and form 2. This means that mode 2 sectors may be "formless" and are sometimes called Yellow Book mode 2. If you're not entirely put off by all this, pay a visit to http://www.onlineinc.com/emedia/AprEM/parker4.html. See http://www.cd-info.com/CDIC/Bibliography.html for information on where to get paper copies of the standards. You can download some of them from http://www.ecma.ch/. ECMA-119 describes ISO-9660, and ECMA-130 sounds a lot like "yellow book" if you say it slowly. Subject: [2-3] How do I know what format a disc is in? You can usually tell by looking at the packaging and/or the disc itself: - CD-DA discs will have a "Compact Disc Digital Audio" logo; - CD+G discs will have the words "CD Graphics"; - CD-i discs will have a "Compact Disc Interactive" logo; - VideoCD discs will have a "Compact Disc Digital Video" logo and/or the words "VideoCD". Subject: [2-4] How does CDROM copy protection work? There are several possibilities; as yet no developers have come forward and announced what they're doing (for obvious reasons). A simple and commonly seen technique is to increase the length of several files on the CD so that they appear to be hundreds of megabytes long. This is accomplished by setting the file length in the disc image to be much larger than it really is. The file actually overlaps with many other files. So long as the application knows the true file length, the software will work fine. If the user tries to copy the files onto their hard drive, or do a file-by-file disc copy, the attempt will fail because the CD will appear to hold a few GB of data. (In practice this doesn't foil pirates, because they always do image copies.) One possible implementation, given sufficient control over the reader and mastering software, is to write faulty data into the ECC portion of a data sector. Standard CDROM hardware will automatically correct the "errors", writing a different set of data onto the target disc. The reader then loads the entire sector as raw data, without doing error correction. If it can't find the original uncorrected data, it knows that it's reading a "corrected" duplicate. This is really only viable on systems like the Sony Playstation, where the drive mechanism and firmware are well defined. A less sophisticated but nontheless effective method is to press a silver CD with data out beyond where a 74-minute CD can write. Copying the disc would then require special CD-R blanks, moving the data and hacking the disc to compensate, or pressing silver discs with the pirated data. If taken too far, though, the disc can become unreadable on some drives. The approach PC software houses have taken lately is to use nonstandard gaps between audio tracks and leave index marks in unexpected places. These discs are uncopyable by most software, and it may be impossible to duplicate them on drives that don't support disc-at-once recording (see section (2-9)). A recent innovation is TTR Technology's DiscGuard (http://www.ttr.co.il). They claim to be able to write a signature onto pressed CDs and CD-Rs that is detectable by all CD-ROM drives but isn't reproducible without special hardware. A program could use this for copy protection by checking for the presence of the signature, and refusing to run if it's not there. Subject: [2-5] What's a multisession disc? A session is a recorded segment that may contain one or more tracks of any type. The CD recorder doesn't have to write the entire session at once, but the last session on a disc must be "closed" before a standard audio CD or CDROM player will recognize it. Additional sessions can be added until the *disc* is closed or there's no space left. Multisession writing was first used on PhotoCD discs, to allow additional pictures to be appended. Today it's most often used with "linked" multisession discs, and occasionally for CD-Extra discs. These require a bit more explanation. When you put a data CD into your CDROM drive, the OS finds the last session on the disc and reads the directory from it. (Well, that's how it's supposed to work. Depending on your operating system and CDROM drive, you may get different results.) If the CD is ISO-9660 format - which it almost certainly is unless it's a Macintosh CD written in HFS - the directory entries can point at any file on the CD, no matter which session it was written in. Most of the popular CD creation programs allow you to "link" one or more earlier sessions to the session currently being burned. This allows the files from the previous sessions to appear in the last session without taking up any additional space on the CD (except for the directory entry). You can also "remove" or "replace" files, by putting the new version into the last session, and not including a link to the older version. In contrast, when you put an audio CD into a typical CD player, it only looks at the first session. For this reason, multisession writes don't work for audio CDs, but as it happens this limitation can be turned into an advantage. See section (3-14) for details. This limitation does *not* mean you have to write an entire audio CD all at once; see section (2-9) for an overview of track-at-once writing. Note that mixing MODE-1 (CDROM) and MODE-2 (CDROM-XA) sessions on a single disc isn't allowed. You could create such a thing, but CDROM drives would have a hard time recognizing it. See also http://www.adaptec.com/support/cdrec/multisession.html, which goes into more depth. Subject: [2-6] What are subcode channels? There are eight subcode channels (P,Q,R,S,T,U,V,W). The exact method of encoding is beyond the scope of this FAQ, but it should be noted that the data is distributed uniformly across the entire CD, and each channel can hold a total of about 4MB. The P subcode channel can be controlled with the JVC/Pinnacle recorders, but apparently isn't used for much. The Q subcode channel includes useful information, which can be read and written on many recorders. The user data area contains three types of subcode-Q data: position information, media catalog number, and ISRC code. Other forms are found in the lead-in, and are used to enable multisession and describe the TOC (table of contents). The position information is used by audio CD players to display the current time, and has track/index information. This can be controlled when doing Disc-At-Once recording. The ISRC (International Standard Recording Code) is used by the recording industry. It states the country of origin, owner, year of issue, and serial number of tracks, and may be different for each track. It's optional; many CDs don't use this. The media catalog number is similar, but is constant per disc. Note these are different from the UPC codes. The R-W subcode channels are used for text and graphics in certain applications, such as CD+G (CD w/graphics, supported by SegaCD among others). A new use has been devised by Philips, called ITTS. It enables properly equipped players to display text and graphics on Red Book audio discs. The most recent result of this technology is "CD-Text", which provides a way to embed disc and track data on a standard audio CD. The other subcode channels are generally inaccessible and unused. For more details, see the book by Pohlmann mentioned in section (2-1); _Principles of Digital Audio_, 3rd edition, by Ken Pohlmann, McGraw-Hill, 1995 (ISBN 0-07-050469-5); or _The Art of Digital Audio_, 2nd edition, by John Watkinson, Focal Press, 1994 (ISBN 0-240-51320-7). Subject: [2-7] Are the CD Identifier fields widely used? At present, not many manufacturers use them, and not all devices can read all of the fields. Subject: [2-8] 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. Subject: [2-9] What's the difference between disc-at-once and track-at-once? There are two basic ways of writing to a CD-R. Disc-at-once writes the entire CD in one pass, possibly writing multiple tracks. The entire burn must complete without interruption, and no further information may be added. Track-at-once allows the writes to be done in multiple passes. There is a minimum track length of 300 blocks (600K for typical data CDs), and a maximum of 99 tracks per disc, as well as a slight additional overhead associated with stopping and restarting the laser. With some software, track-at-once recording leaves run-in and run-out blocks between tracks, resulting in slight but annoying clicks between tracks. Astarte, the publishers of "Toast", have asserted that clicks between tracks are caused by bugs in the CD-R drive firmware or in the software used to write the discs, and that they can be avoided. (The difference may be that, so long as you don't stop writing between tracks, it's not necessary to write the run-in and run-out blocks. No extra blocks, no extra clicks.) Some drives and/or software packages may not let you control the size of the gap between audio tracks when recording in track-at-once mode, leaving you with 2-second gaps even if the original didn't have them. A few recorders, such as the Philips CDD2000, allow "session-at-once" recording. This gives you disc-at-once control over the gaps between tracks, and allows you to write in more than one session. This can be handy when writing CD Extra discs (see section (3-14)). There are some cases where disc-at-once recording is required. For example, it may not be possible to make backup copies of some kinds of discs without using disc-at-once mode (e.g. PSX games or copy-protected PC games). Also, some CD mastering plants may not accept discs recorded in track-at-once mode, because the gaps between tracks show up as errors. The bottom line is that disc-at-once recording gives you more control over disc creation, especially for audio CDs, but isn't always appropriate or necessary. It's a good idea to get a recorder that supports both disc-at-once and track-at-once recording. Subject: [2-10] Differences between recording from an image and on-the-fly? Many CD-R creation packages will give you a choice between creating a complete image of the CD on disk and doing what's called "on-the-fly" writing. Each method has its advantages. Disc image files are sometimes called virtual CDs or VCDs (not to be confused with VideoCD). These are complete copies of the data as it will appear on the CD, and so require that you have enough hard drive space to hold the complete CD. This could be as much as 650MB for CD-ROM or 747MB for an audio disc when using 74-minute blanks. If you have both audio and data tracks on your CD, there would be an ISO-9660 filesystem image for the data track and one or more 16-bit 44.1KHz stereo sound images for the audio tracks. On-the-fly recording often uses a "virtual image", in which the complete set of files is examined and laid out, but only the file characteristics are stored, not the data. The contents of the files are read while the CD is being written. This method requires less available hard drive space and may save time, but increases the risk of buffer underruns (see (4-1)). With most software this also gives greater flexibility, since it's easier to add, remove, and shuffle files in a virtual image than a physical one. A CD created from an image file would be identical to one created with on-the-fly recording, assuming that both would put the same files in the same places. The choice of which to use depends on user preference and hardware capability. Subject: [2-11] How does an audio CD player know to skip data tracks? There are subcode flags for each track: Data - if set, the track contains data; if not, the track contains audio. Digital Copy Permitted - if set, copying is permitted. Four-Channel Audio - the Red Book standard allows four-channel audio, though very few discs have ever been made that use it. Pre-Emphasis - set if the audio was recorded with pre-emphasis. The last three are rarely used. Subject: [2-12] How does CD-E/CD-RW compare to CD-R? CD-RW is short for CD-Rewritable. It used to be called CD-Erasable (CD-E), but some marketing folks changed it so it wouldn't sound like your important data gets erased on a whim. The difference between CD-RW and CD-R is that CD-RW discs can be erased and rewritten, while CD-R discs are write-once. CD-RW drives use phase-change technology. Instead of creating "bubbles" and deformations in the recording dye layer, the state of material on the disc changes from crystalline to amorphous form. These discs are not writable by current CD-R drives, nor readable by many existing CD readers (the reflectivity of CD-RW is far below silver CDs and CD-R, so an Automatic Gain Control circuit is needed). Drives that can write both CD-R and CD-RW formats are now shipping, and most new CDROM drives are expected to support CD-RW. (Reports have indicated that CD-RW discs don't always read at full speed on some drives, however.) CD-RW discs use the CD-UDF write-once filesystem, which means they won't be readable under some operating systems even if the hardware is compatible. Oddly enough, it may be easier for a DVD drive to read CD-RW discs than CD-R discs, because of the way the media is constructed. All known CD-RW drives can write CD-R discs as well. The first batch of CD-RW is much more expensive than CD-R. This is expected to change as sales volumes increase. There is a limit to the number of times an area of the disc can be rewritten, but that number is relatively high (somewhere between 1000 and 100,000). For an *excellent* description of the techology, see http://www.onlineinc.com/cdrompro/0996CP/bennett9.html. Some interesting articles on CD-RW - including an editorial critical of the new technology - can be found at: http://www.onlineinc.com/emedia/JanEM/news1.html#erase http://www.onlineinc.com/emedia/FebEM/writer2.html http://www.onlineinc.com/emedia/AprEM/parker4.html#bennett Subject: [2-13] Can DVD drives read CD-Rs? The only discs that a DVD drive is guaranteed to read are DVD discs. Support for CD-ROM, CD-R, and CD-RW may be included, but is by no means guaranteed. CD-R was designed to be read by an infrared 780nm laser. DVD uses a visible red 635nm or 650nm laser, which aren't reflected sufficiently by the organic dye polymers used in CD-R media. Some DVD drives will come with two lasers so that they can read CD-R. Some DVD drives may be unable to read multisession discs. If the box doesn't say that something is supported, assume that the feature isn't. The MultiRead logo indicates that a CD or DVD player can read all existing CD formats, including CD-ROM, CD-DA, CD-R and CD-RW. See the press release at http://www.osta.org/osta/html/press/pr150797.html. Subject: [2-14] Should I wait for DVD-R? No. The writers are still very expensive and not widely available through consumer channels. DVD readers for video and for computers are shipping, but it will be some time before DVD-R is available to consumers. Subject: [2-15] What are "jitter" and "jitter correction"? Jitter is a complex concept that appears in several different areas. In the context of digital audio extraction from CD-DA discs, jitter causes extracted audio samples to be doubled-up or skipped entirely. Jitter correction is the process of restoring the audio data to its intended form. The problem occurs because the Philips CD specification doesn't require block-accurate addressing. While the audio data is being fed into a buffer (a FIFO whose high- and low-water marks control the spindle speed), the address information for audio blocks is pulled out of the subcode channel and fed into a different part of the controller. Because the data and address information are disconnected, the CD player is unable to identify the exact start of a frame. This mismatch will span less than 1/75th of a second, but if it happens several times it will be noticeable as clicks and pops. On a CD-ROM, the blocks have a 12-byte sync pattern in the header, as well as a copy of the block's address. It's possible to identify the start of a block and get the block's address by watching the FIFO alone. With most CD-ROM drives that support digital audio extraction, you can get jitter-free audio by using a program that extracts the entire track all at once. The problem with this method is that if the hard drive being written to can't keep up, some of the samples will be dropped. (This is similar to a CD-R buffer underrun, but since the output buffer used during DAE is much smaller than a CD-R's input buffer, the problem is magnified.) Some CD-ROM drives, such as most of the Plextor models, include special circuitry that enables them to accurately detect the start of a block. An approach that has produced good results is to do jitter correction in software. This involves performing overlapping reads, and then sliding the data around to find overlaps at the edges. Most DAE programs will perform jitter correction. Subject: [2-16] Where can I learn more about the history of CD and CD-R? I don't have a favorite book or web site to recommend. Poke around on the http://www.cd-info.com/ web site, especially some of the books and links listed in the bibliography. ------------------------------------------------------------------------------ Subject: [3] How Do I... This is general information about recommended ways to do specific tasks. Subject: [3-1] How do I copy a data CD? Several publishers have CD-to-CD copiers. Two low-cost versions are Adaptec EZ-SCSI, which comes with a simple CD copier called "CD Copier", and Jeff Arnold's freeware CD2CD. The easiest and most reliable method to make copies of single-track data CDs is also the least expensive: CD2CD runs under DOS and works very well with a wide variety of hardware. Software such as Arnold's and Adaptec's will allow you to make a CD image on a hard drive that can then be written to multiple CDs. The fancier packages will usually provide a way to do this as well, but the software tends to be more complicated and harder to use. Multi- session and other fancy formats require more sophisticated software, such as Jeff Arnold's SNAPSHOT. It's important to remember that, when copying directly from one CD to another, the source MUST be faster than the target, and must be error-free. If the source pauses or spins down to read a marginal area of the disc, the target may outrun the source, and the CD-R will only be useful as a frisbee. Most programs have a "test write" feature that put the CD-R device into a mode where it goes through all the motions but doesn't actually write anything; it's a good idea to do this right before copying. Subject: [3-1-1] Why can't I just do a block copy like a floppy? CDs don't have circular tracks. They're laid out on a spiral, with multiple sessions composed of multiple tracks composed of sectors, and the data in the sectors is interleaved and spread over a large area. The sector format is standard, but there's more than one standard. ("The nice thing about standards is that there's so many to choose from." -- Andrew S. Tannenbaum) The ability to read certain portions of a CD depends on the CD firmware. Some CD players aren't capable of understanding multi-session discs or of reading audio tracks as digital data. Jitter, described in section (2-15), is also a problem for most drives. Subject: [3-2] How do I extract tracks from, or copy all of, an audio CD? To copy from CD to CD, the source drive needs to support digital audio extraction, which is rather rare among older drives. A copier such as Adaptec's "CD Copier" will copy the CD track-by-track, while one like Jeff Arnold's SNAPSHOT will use disc-at-once recording. Some programs will only copy the CD to the hard drive and from there to CD-R, some will allow CD-to-CD directly but only if the source is a SCSI CDROM, and some will work with IDE or SCSI. If you're just interested in extracting digital audio, you don't even need a CD-R unit, just a CDROM drive that supports DA extraction and some software. See http://www.tardis.ed.ac.uk/~psyche/cdda/ for the CD-DA FAQ and a variety of software. Different drives can extract digital audio at different speeds. For example, the Plextor 6Plex can extract audio at 6x, while the NEC 6Xi can only extract at 1x. It should be pointed out that, while digitally extracted audio is an exact copy of the data on the CD, it's an exact copy as your CD player perceives it. Different drives or different runs with the same drive can extract slightly different data from the same disc. The differences are usually inaudible, however. The quality of the CD-R audio output depends mostly on how well your CD player gets along with the brand of media you're using. See the next section for some comments about avoiding clicks and pops. Some drives have trouble starting at the exact start of audio tracks. The extraction starts a few blocks forward of where it should, and ends a few blocks later, so the track may not sound quite right and the extraction program will report errors at the end of the last track. See section (4-19). One minor note: the data on audio CDs is stored in "Motorola" big-endian format, with the high byte of each 16-bit word first. AIFF files also use this format, but WAV files use "Intel" little-endian format. Make sure your software deals with the endian-flipping correctly. Byte-swapped CD audio sounds like noise. Subject: [3-3] How do I avoid clicks on audio CDs? You should use disc-at-once recording. Track-at-once writes some extra run-in and run-out sectors that may end up getting played by audio CD players as a click. You need to copy all of the tracks to a hard drive, and then write them all at once using a program like Jeff Arnold's DAO or Adaptec's Easy-CD Pro 95. If you're using disc-at-once recording, and are still getting a short click at the *start* of every track, then your recording software is probably writing the sound file with the headers still on it. You should either use a smarter program, or remove the header manually (for a .WAV file it's usually the first 44 bytes). If you are getting clicks in the middle of a track, they are either being added when pulling the data off the disc or when writing it. If the .WAV (AIFF on the Mac) file plays without clicks, then your CD recorder may be suffering from buffer underruns during the write process. If there are clicks in the copy on your hard drive, then your method of extracting audio is flawed (see section (3-2)). If you are getting clicks at the end of a track, it's possible that the software used to create the .WAV file put some information at the very end, which is legal but not handled correctly by some CD-R software. See section (3-12) for tips on using CoolEdit to remove the data. If you are finding that tracks extracted from CDs don't have clicks but tracks that you have recorded or edited do, chances are the data size isn't a multiple of 2352 bytes, and the last block is being filled with junk. Jeff Arnold's DAO will fill out the last block with zeros (digital silence) if there is space left over, but most of the other programs will write garbage that is audible as a short (less than 1/75th second) click. A program called "WAVECLIP" will remove .WAV headers and footers, and will either pad out the last block or remove silence from the end of a WAV file to make it an exact multiple of 2352 bytes. The program is available from http://www.ptialaska.net/~syntec/waveclip.zip. Some CDROM and CD-R drives have trouble extracting digital audio at high speed, so if you're getting lots of clicks and pops when extracting you should try doing it at a slower speed. You may also run into trouble if you try to extract faster than your hard drive can write. One user found that he was able to eliminate clicks and pops by defragmenting his hard drive. If you must use track-at-once, make sure you're writing it all in one session. Most, if not all, CD players won't see audio tracks beyond the first session. A distantly related problem can arise if you use "shuffle play" to play random tracks from a CD-R. If the audio of track N begins immediately, some CD players will slide from the end of track N-1 into the start of track N, playing a short burst of track N before seeking elsewhere. This can be avoided by putting a gap at the start of such tracks (e.g. with "INDEX 01 xx:yy:zz" in a DAO cue sheet). Finally, some people who got "static" in audio recorded on an HP 4020i found that reducing the DMA transfer rate to 2MB/sec helped. Subject: [3-4] How do I copy Sony Playstation, Sega Saturn, or 3DO discs? Jeff Arnold has a utility called SNAPSHOT for doing this; see his web page at http://www.goldenhawk.com/. Note that this software does NOT defeat the copy protection. Incidentally, posting requests or advertisements for pirated software on one of the Usenet groups is generally regarded as a mark of extreme stupidity. Whatever your opinion of software piracy, it is against the law in much of the world. Subject: [3-5] How do I get long filenames onto a disc? There are several different ways, most of which only work with some operating systems. The next few sections discuss the various methods. See http://www.adaptec.com/support/cdrec/filename.html for a detailed description with some examples. Getting mixed-case filenames onto a disc is a similar problem. Burning an ISO-9660 disc with lower-case filenames isn't recommended, because some systems aren't able to access the files even though they appear in directory listings. Subject: [3-5-1] ISO-9660 Level 1 ISO-9660 defines names to be the familiar 8+3 convention that MS-DOS users have suffered through for many years: eight characters for the name, a period ("full stop" for those of you in the U.K.), followed by three characters for the file type, all in upper case. Many special characters (space, hyphen, tilde, equals, and plus) are forbidden. There's also a file version number, separated from the name by a semicolon, but it's usually ignored. Level 2 ISO-9660 allows longer filenames and deeper directory structures (32 levels instead of 8), but isn't usable on some systems, notably MS-DOS. Level 3 ISO-9660 allows non-contiguous files, useful if the file was written in multiple packets with packet-writing software. Some of the CD creation programs will let you select how closely you want the CD to conform to the ISO-9660 standard. For example, Easy-CD Pro 95 can restrict filenames to be ISO-9660 compliant, or allow the full set of valid MS-DOS filenames. (Most systems can handle MS-DOS filenames.) Subject: [3-5-2] Rock Ridge The Rock Ridge extensions to ISO-9660 define a way for UNIX-isms like long mixed-case filenames and symbolic links to be supported. Because it's still an ISO-9660 filesystem, the files can still be read by machines that don't support Rock Ridge; they just won't see the long forms of the names. Rock Ridge is supported by UNIX systems. DOS, Windows, and the Mac don't currently support it. Copies of the Rock Ridge standard and System Use Sharing Protocol (SUSP) can be found at ftp://ftp.ymi.com/pub/rockridge/. Pay a visit to http://makecd.core.de/Rock_Ridge_Amiga_Specific for a description of Amiga-specific extensions. Subject: [3-5-3] HFS HFS is the Hierarchical File System, used by the Macintosh. This is used in place of the ISO-9660 filesystem, making the disc unusable on systems that don't support HFS. At present, the systems that can read HFS CD-ROMS are Macs, Amigas (with AmiCDROM, available from ftp://ftp.cdrom.com/pub/aminet/disk/cdrom/), PCs running Linux or OS/2 (with appropriate patches), the Apple IIgs, and SGI machines running Irix (they appear as AppleDouble format). Some authoring packages for the Mac and Windows allow the creation of "hybrid" CDs that have both an ISO-9660 filesystem and an HFS filesystem. Apple has defined some ISO-9660 extensions that allow Macintosh files to exist with file and creator types on ISO-9660 CDROMs. A description of the extensions is available from: http://devworld.apple.com/dev/technotes/fl/fl_36.html Subject: [3-5-4] Joliet Microsoft, being Microsoft, created their own standard called "Joliet". This is currently supported by Win95 and WinNT. It's useful when doing backups from Win95 onto a CD-R, because the disc is still readable as ISO-9660 but shows the long filenames under Win95. The spec can be found at http://www.ms4music.com/devl/dvjoliet.htm. Linux can be taught to read Joliet discs by patching the kernel. See http://www-plateau.cs.berkeley.edu/people/chaffee/joliet.html. Ditto for OS/2; see: http://service.software.ibm.com/os2ddpak/html/miscellb/os_2warp/updatedc/index.htm Subject: [3-5-5] Romeo Adaptec's software allows creation of discs in "Romeo" format. It's not clear how widely this is supported. Subject: [3-5-6] ISO/IEC 13346 and ISO/IEC 13490 These are new standards intended to replace ISO-9660. So far they're not widely used. See http://www.mv.com/users/kaikow/. Subject: [3-6] How do I use a CD-i disc on a PC? Short answer: you don't, unless you have a CD-i add-on board. Even if you have a CD reader compatible with the CD-i (Green Book) standard, there are still a number of obstacles in your way. The filesystem used isn't ISO-9660, and CD-i players are based around a 680x0 CPU and have special hardware for video and audio. Longer answer: it depends on what kind of disc it is, and what you mean by "use". PhotoCD and VideoCD discs are CD-ROM/XA "Bridge Format" discs that play on CD-i players as well as dedicated players and computers. These use the ISO-9660 file system, and can be read with commonly available PhotoCD software and MPEG-1 players. DigitalVideo discs from Philips manufactured before June, 1994 are in CD-i format, not VideoCD format, and require additional hardware to be played on a PC. If your CD-ROM drive supports raw 2352-byte sector reads, it's possible to pull tracks off of a Green Book format disc, and extract audio or MPEG video data. Subject: [3-7] How can I extract disc and track titles from an audio CD? Typical Red Book audio CDs don't have this information. Software audio CD players like those provided by Adaptec or Microsoft require you to type in the information, which is then stored in a database on your hard drive. The discs are identified by computing a signature based on track offsets and other fields. See http://www.cddb.com/ for a full explanation, as well as databases of CD info. Some newer formats, like CD Extra, allow or even require such information to be included on the CD. Some recent CD players are advertised as "CD-Text Ready". These use the CD-Text data embedded in the R-W subcode channel to display disc and track title data. (It remains to be seen whether this will be usable by CD audio programs running on a computer.) Subject: [3-8] How do I copy an 80-minute CD? Since CDs are written in a spiral, the amount of data you can get on a disc is affected by how tightly spaced the "groove" is. A standard Red Book audio CD or Yellow Book CDROM is designed to allow at most 74 minutes of data. By using a tighter spacing on the "groove" on the glass master, or by adjusting the sizes of the "pits" and "lands", manufacturers can get more data onto the disc, but this may make it harder for some CD readers to use the discs. CD-R's have a pre-formed spiral track, and the sector addresses are hard-coded into CD-R media, so there's no flexibility. There *are* 80-minute CD-R blanks, but they're very expensive, and may not work on all systems. The longest possible CD-R is 79 minutes, 59 seconds, 74 frames long, because of the way that the last possible start time of the lead-out is encoded. Such discs are supposedly available directly from TDK (USA sales +1 800 835 8273). It may be possible to create a longer CD by suppressing the leadout, but it's not clear if this is easy or even a good idea. Subject: [3-9] How do I create a PhotoCD? First off, you need to be aware that certain aspects of PhotoCD creation are proprietary to Kodak. Programs like Adaptec's Easy CD Creator will allow you to create discs with files in the PhotoCD format, and you will be able to view the images with Mac or PC programs that understand the PhotoCD fileformat, but you won't be able to look at the disc with a PhotoCD player. http://www.kodak.com/digitalImaging/aboutPhotoCD/aboutPCD.shtml has the glossy brochure information, with some Kodak contact information. http://www.idiom.com/~ggs/ gives you step-by-step instructions and software for creating "real" PhotoCD discs with Kodak's software. The program that Kodak provides (for a fee) will only write to Kodak CD recorders, but a translator available from the web site will allow it to work with GEAR or CDRWIN. Follow the Kodak links on that page. Incidentally, if you're planning to convert your own pictures, you will need a way to get your images digitzed in the first place. Digital cameras like the Apple QuickTake will work, as will video capture boards or frame grabbers. Subject: [3-10] How do I make a CD that will work on a PC or a Mac? If it's just a disc full of data (like JPEG images), writing the disc in minimal ISO-9660 should work. You may have to master it without the volume number (e.g. ";1") at the end of the name. If you need the format to be more flexible, perhaps with separate executables for Macs and PCs, you'll want to build a "hybrid" CD that has two sets of files on it. Adaptec's Toast for the Mac is widely recommended for this. See section (6) for other options. Subject: [3-11] How do I get at different sessions on a multi-session CD? As always, it depends. MS-DOS lets you see the first data session. Win95 lets you see the last data session. Adaptec's "session selector" will let you choose which session you see, but it only works with SCSI CD-ROM drives. Some CD creation software (e.g. Adaptec Easy-CD Writer) writes a complete table of contents in each session, some of which refers back to the files from the previous session, allowing a form of incremental backup. (This will work for ISO-9660 discs, but won't work for HFS. However, this is less painful that it seems because a properly-configured Macintosh will let you mount all the sessions as individual volumes.) Adaptec's Easy-CD Pro will allow you to combine the contents of several previous sessions by creating a new session (use RCD's Load Contents option to read the file/directory info from more than one session, then write and close a new session with that directory structure). Some of it depends on the SCSI driver you have installed. Subject: [3-12] How do I transfer my records or cassettes to a CD? For a nice introduction, see http://www.octave.com/octave/audiocd.html. If you have questions or need a recommendation on a sound card, you might want to try: news:rec.audio.tech news:comp.sys.ibm.pc.soundcard.tech You need to connect the analog output from your record player through a pre-amp (which both pre-amplifies the signal and equalizes it to RIAA standards) to a board in your PC that can digitize analog audio and store it on your hard drive. You can use the A/D (analog-to-digial) converter built into a sound card like a SoundBlaster 16, but the sound quality will not be very good. The sound cards from Turtle Beach (Tropez, Tahiti) and CrystaLake are a step up, and a Digital Audio Labs CardD+ is about as good as it gets for internal A/D cards. If you're really serious, you should get an external A/D converter such as the Symetrix 620, and feed the digital output from that into the computer (another way of accomplishing the same thing is to record to an audio DAT tape and then use the digital output on the DAT recorder; see the next section for details). A problem with some sound cards (really cheap Opti and ESS cards have been named) is that the crystal that controls the recording sample rate is off. If the card doesn't do the sampling at the correct rate, the recorded audio may end up slightly slower or faster than the original. This sort of problem is easy to detect; record something, play it back, and see if it sounds different. When recording, try to get as much signal as possible. Normalization will bring the signal level up, but can't replace parts of the signal that were lost. Sound editing utilities, such as GoldWave or Cool Edit, can be used to equalize, normalize, and even perform noise reduction on your recordings. Adaptec's Easy CD Creator includes an application called "Spin Doctor" that performs most of the tasks needed to transfer LPs to CD. Noise reduction is performed by a program called DART that can be upgraded to a much better version (DART Pro) for a modest fee. Few automated tools can do as good a job cleaning up POPs and other noise as an experienced person, however. If you want to perform the transfer by hand, the following method has been suggested for PC users: - Record directly into Cool Edit, using the highest possible input level that doesn't exceed the maximum. You want to record 16-bit stereo samples at 44.1KHz. - In the "noise reduction" dialog, set FFT size to 8192, FFT precision to 10, and #of samples to 96. - Select a silent passage between songs or from the end of the record. It can have some crackling but no huge pops. Set the noise level. - Select the entire track and perform noise reduction at about 70%. - Select the entire track and normalize it. - Manually remove any big pops (easily located by zooming in to the general area and switching to "spectral view" in the edit menu) by zooming in on them and amplifying them to about 8%. You only need to select the channel (left or right) in which the offending data occurs. If it occurs across BOTH channels, you may get a better result by deleting that part of the track and reconstructing it in such a way that it remains smooth... if that's not possible, make one channel smooth and then amplify the other to 8%. Cool Edit optionally leaves a blob of data at the end of the .WAV file, which is legal in the file format but not expected by some utilities. To avoid this, go into the "Options" menu and select "Info" (for Cool Edit 96, it's under the "View" menu). There is a check box here labeled "Fill * fields automatically". Make sure the box is unchecked, and don't put any information into the fields. (For Cool Edit 96, there may be a simple checkbox in the file save dialog as well.) Cool Edit can be found at http://www.syntrillium.com/. A similar product called "GoldWave" can be found at http://www.goldwave.com/. A fancy commercial product called Sound Forge is described on http://www.sfoundry.com/. Don't forget that CD audio is 16-bit stereo at 44.1KHz, and will chew up disk space at roughly 176K per second. Playing back large sound files is difficult with simple-minded applications like the standard Win95 WAV player, because they try to load the entire file into memory all at once. Cool Edit 96 is able to play files back as it reads them, and works very well even over a network. See section (3-3) for some tips on avoiding clicks when committing the audio to CD. For those of you wondering what the deal with pre-whatever is, this little tidbit is courtesy mikrichter@interramp.com: "Preemphasis has been used since the earliest days of commercial recording. In general, the high-frequency content of the music (or whatever) being recorded is low and the noise is high. Therefore, treble was boosted and lows were cut by a preemphasis curve which was removed in playback. The standard RIAA curve for turnover and rolloff (the amount and frequency for treble and bass, respectively) was not accepted universally until the 50's, and some fine preamps offered selectable values with presets for the common curves into the early transistor era." Subject: [3-13] How do I transfer an audio DAT tape to CD? Buy a card that will allow you to go from DAT to hard disk digitally. Make sure you get one that can handle the same digital standard the DAT recorder uses, i.e. S/PDIF (Sony/Phillips Digital Interface Format, sometimes referred to as "domestic") or AES/EBU ("professional"). Some of the solutions for the PC are the DigiDesign AudioMedia (see http://www.digidesign.com/), the Zefiro Acoustics ZA2 (see http://www.zefiro.com/), the AdB Digital Multiwav Pro (see http://www.adbdigital.com/), the Digital Audio Labs CardD+ (see http://www.digitalaudio.com/products.htm), or the Turtle Beach Fiji (See http://www.tbeach.com/products/fiji.htm). The CardD+ comes highly recommended. There may be newer versions of these products, so be sure to check out the web sites. You should record from the DAT onto your hard drive, and then record the CD from there. If you try to record directly from DAT you'll likely end up with a lot of wasted CD-Rs due to buffer underruns or minor mistakes. You should use Disc-At-Once recording for best results; Jeff Arnold's DAO software is recommended for this on the PC. One issue you need to be aware of is that some DAT recorders can only record at 48KHz, while CDs are recorded at 44.1KHz. If this is the case with your equipment, you will have to do a sample rate conversion. The DSP on cards like the ZA2 will do this for you, or you can use an audio editing program like CoolEdit or Sound Forge. There *are* CD-R drives that have analog inputs, and can record directly from audio sources. See section (5-12). If you use a DAT and haven't been to the DAT-heads home page, you should definitely check out http://www.atd.ucar.edu/rdp/dat-heads/. If you want to manipulate audio DATs directly from your computer, you need a DDS drive with special firmware. The SCSI DDS drives that are typically sold for backups don't have the firmware required to handle DAT tapes. Most SGI workstations can do this, and Mac users should check out http://www.demon.co.uk/gallery/StudioDAT.html. If you're interested in mastering production audio CDs, you should take a look at http://www.sadie.com/. Subject: [3-14] How do I put audio and data on the same CD? There are two ways to do this. The first is to put the data on track 1 of the CD, and audio on the next several tracks (discs created this way are referred to as "mixed-mode" CDs). The CDROM drive will automatically look at track 1 and ignore all other tracks, so you'll be able to get at the data and -- depending on the operating system -- will be able to play the audio tracks. Remember that all of the tracks, both audio and data, need to be recorded in a single session. See section (3-2). The down side of this is that audio CD players may attempt to play track 1, which can be obnoxious or downright harmful to audio equipment. Most modern CD players are smart enough to ignore data tracks, so this won't usually be a problem. The other approach is to create a multisession disc with the audio tracks in the first session and the data track in the second. This is how CD Extra (the format formerly known as CD Plus) works. Audio CD players only look at the first session, and CDROM drives are (supposed to) start with the last session, so it all works out. What happens when you try to play one of these as audio in your CDROM drive? As with most things multisession, it depends on your drive. (The control panel that comes with the Plextor 8Plex does the right thing. If you're using a different drive, you're on your own.) There's actually a third way to do this that involves putting the data track into the extended pregap of the first audio track. Instead of the audio starting at minute:second:frame 00:02:00, the data starts there, and the pregap is adjusted accordingly. This method never gained popularity because some drives started playing at 00:02:00 regardless. For more information (mainly aimed at Macintosh users), see http://www.musicfan.com/ecd/what.html. Subject: [3-15] How do I make a bootable CD? On a Mac, this is reasonably straightforward. A CD can be bootable if it has a bootable system folder on it. Tell the recording software that you want to make the CD bootable; this usually involves clicking in a checkbox before burning the first session. Then, copy a bootable system folder onto the disc. An easy way to create an appropriate system folder is to launch the system installer, tell it you want to do a "Custom" install, choose the "Universal System" option, and then install it onto the CD source volume. Holding down the 'c' key while booting while cause the Mac to boot from an internal CDROM drive. Alternatively, the "Startup Disk" control panel will allow you to select a CDROM. For PCs, it's a bit more of a challenge. The BIOS on some machines supports bootable CDs. Phoenix (the BIOS developer) has created the El Torito standard for doing this sort of thing. You can find specifications and a "how to" guide at http://www.ptltd.com/techs/specs.html. Step-by-step procedures with varying levels of detail can be found here: http://mail.ncku.edu.tw/~thlx/bootcd.htm http://incolor.inetnebr.com/guardian/boot-cd.shtml ftp://ftp.netcom.com/pub/fa/fadden/bootcd.txt The "BOOTISO" utility may come in handy, and can be found here: http://www.geocities.com/SiliconValley/Way/2996/index.html CDR Publisher can make bootable CDs for PCs and UNIX. WinOnCD 3.0 and Adaptec Easy CD Creator 3.0 can create bootable CDs for PCs. When booting the PC, you may need to change the boot order in the BIOS from the typical "A, C" to "A, SCSI, C", and configure the SCSI interface to attempt to boot from CD. Subject: [3-16] How do I convert home videos into video on CD? This topic is largely outside the scope of this FAQ, so I'm not going to go into much depth. The Usenet newsgroup news:rec.desktop.video is more applicable. I'm not aware of an FAQ for that group, but the links found at http://www.cris.com/~videoguy/jump.htm will get you started. You need a capture card to transfer the video to your hard drive. Capturing video will eat up 2MB or more per *second* of video at full resolution (640x480x24 at 60 fields per second for NTSC) with a reasonable degree of compression, so this isn't something to be undertaken lightly. The lower your quality requirements, the lower the bandwidth requirements. If MPEG is your only interest, you might be better off with an MPEG-only card rather than a hobbyist video capture board. http://www.b-way.com/ and http://www.darvision.com/ are good places to look. The Broadway card has been given high marks for quality. Once you've captured the video, you'll probably want to edit it (at least to clip out unwanted portions or add titles). Packages for doing this, like Adobe Premiere and Ulead MediaStudio, are usually included with the capture card. These will also let you adjust the resolution, color depth, and compression quality to output the video so that it's suitable for playback on double- or quad-speed CDROM drives. You can convert AVI files to MPEG and vice-versa with a program from Ulead (see http://www.ulead.com/), Xing Technologies, or several other vendors. You should be able to create QuickTime or AVI movies using the compression codec of your choice from the video editing software. If you want to try creating a White Book VideoCD, which can be viewed on a VideoCD playback device like a Philips CD-i or from a computer with appropriate hardware and software, CD-R software packages like CD Creator and WinOnCD can convert AVI movies into MPEG and write them to CD in the necessary format. (One warning: CD Creator was picky about the parameters used in the MPEG encoding. You may encounter difficulties unless your MPEG sources match the exact specifications.) John Schlichther's AVI2MPG1 combines standard tools into an easy-to-use program for Win95 and NT; use it with the "-v" flag to make a VideoCD-compatible stream that ECDC will accept (http://www.mnsi.net/~jschlic1/). If you're running Linux you should take a look at Bernhard Schwall's "avi2yuv" program. It converts M-JPEG movies created with popular video capture boards into a format accepted by the Berkeley MPEG-1 and MPEG-2 encoders (ftp://bmrc.berkeley.edu/pub/mpeg/). The README for avi2yuv lists the additional software packages (all of which are free and run under Linux) needed for creating MPEG movies complete with sound. Most (all?) of the utilities can also be built to run under DOS. Easy CD Creator requires that an MPEG MCI driver be installed in the system (unlike CD Creator, it doesn't come with Xing's MPEG software). The popular VMPEG 1.7 doesn't quite work: ECDC can't see the audio, and you're not allowed to select the frame to view when shuffling streams around. If you have VMPEG installed as the MCI driver -- select "About ECDC" from the Help menu to check -- you need to *remove* VMPEG and then install ActiveMovie. (I removed it by going into the Advanced section of the Multimedia control panel, expanding "Media Control Devices", selecting vmpegdll, and clicking on "Remove", but you may be able to use Add/Remove Programs instead.) Finally, you should be aware that MPEG playback is rather CPU intensive, and it's possible to create movies that don't play very well without hardware support. The PowerPC QuickTime MPEG extension (available from http://quicktime.apple.com/) works well, as does Microsoft ActiveMovie (http://www.microsoft.com/, available as part of MSIE 3.02 or separately in the DirectX 5.0 download area), but most of the UNIX players won't play the audio. Software MPEG playback is becoming easier as CPUs become more powerful, but it's not yet a standard component of many systems. VideoCDs can only be read by CDROM drives capable of reading CDROM-XA discs. If your drive doesn't claim to support PhotoCD, you're probably out of luck. Microsoft's ActiveMovie and Apple's Video Player can play movies off of a VideoCD (Apple's AVP will scan the CD; with ActiveMovie you need to look for and open the ".dat" files in the "mpegav" directory). Subject: [3-17] How can I burn several copies of the same disc simultaneously? You can if you have several CD-R drives and the right software. Two examples are CD Rep from Prassi Software (section 6-1-21) and DiscJuggler from Padus (section 6-1-27). Both products are SCSI multiplexors. You use your existing CD writing application (such as Easy-CD Pro 95) like you normally would, and the program sends the same commands to each of the CD-R drives. There are a number of limitations, notably that all devices must use the same command set and may need to have the same firmware revision. There may also be limits on the number of drives you can have attached at once. DiscJuggler bills itself as "the professional CD Duplicator", CD Rep as "the ultimate professional recording solution". If you're interested in either of these, you should read the web pages for both, and compare the features available. There are several hardware-based solutions to this, including CD-R units that support daisy-chaining, and control units that vary from the simple (a handful of units wired together) to the complex (robotic arms to move discs around). Most cost more than a Hyundai. See http://www.cd-info.com/CDIC/Technology/CD-R/duplication.html for an overview of several different hardware solutions. Subject: [3-18] Can I make copies of copies? The following comes from Jeff Arnold: "I do not recommend making "copies of copies" with SNAPSHOT. The reason this does not always work is because many CDROM readers do not perform error correction of the data when doing raw sectors reads. As a result, you end up with errors on the copy that may or may not be correctable. When you make a second-generation copy of the same disc, you will make a disc that has all of the errors of the first copy, plus all of the new errors from the second reading of the disc. The cumulative errors from multiple copies will result in a disc that is no longer readable." Some further explanation is needed here. The heart of the problem is the way that that the data is read from the source device. When a program does "raw" sector reads, it gets the entire 2352-byte block, which includes all of the error correction data for the sector. Rather than applying the error correction to the sector data, the drive just hands back the entire block, errors and all. This problem can be avoided by using "cooked" reads and writes. Rather than creating an exact duplicate of the source sector - possibly propagating errors along the way - cooked reads pull off the error- corrected 2048 byte sector, and let the CD-R regenerate all the appropriate error correction and other headers. Ideally SNAPSHOT would be able to do the error correction in software, but apparently there's no readily available code that does this. It could also read each block twice, once in raw mode and once in cooked, but that would double the read time. This begs the question, why not just use cooked writes all the time? First of all, some recorders (e.g. Philips CDD2000 and HP4020i) don't support cooked writes. (Some others will do cooked but can't do raw, e.g. the Pinnacle RCD-5040.) Second, not all discs use 2048-byte MODE-1 sectors. There is no true "cooked" mode for MODE-2 data tracks; even a block length of 2336 is considered raw, so using cooked reads won't prevent generation loss. It is important to bear in mind that the error correction included in the data sector is a *second* layer of protection. The CIRC ECC encoding that keeps your audio CDs from popping every time a fingerprint is encountered will also correct most errors on data discs. The error detection and correction information included in data sectors serves to correct further errors, since most data can't tolerate errors the way audio can. (The dropped audio samples are replaced with interpolated data. This wouldn't work very well for data.) The original version of this quote went on to comment that Plextor and Sony CDROM drives were not recommended for making copies of copies. The reason they were singled out is because they are the only drives that explicitly warned about this problem in their programming manuals. It is possible that *all* CDROM drives behave the same way. (In fact, it is arguably the correct behavior... you want raw data, you get raw data.) The documentation for SNAPSHOT describes whether "raw" or "cooked" writes are recommended for several different CD-R drives. See the section on "USING THE /COOKED OPTION" in "snapshot.txt", found in ftp://ftp.cdarchive.com/pub/jarnold/readme.zip. The final answer to this question is, you can safely make copies of copies, so long as the disc is a MODE-1 CDROM and you're using "cooked" writes. Copies made with "raw" writes may suffer generation loss because of uncorrected errors. Audio tracks don't have the second layer of ECC, and will be susceptible to the same generation loss as data discs duplicated in "raw" mode. Some drives may turn off some error-correcting features, such as dropped-sample interpolation, during digital audio extraction, or may only use them when extracting at 1x. If you want to find out what your drive is capable of, try extracting the same track from a CD several times at different speeds, then do a binary comparison on the results. Subject: [3-19] How can I compress or encrypt data on a CD? The easiest way is to use your favorite compression or encryption utility and process the files before putting them on the CD. However, this isn't transparent to the end user. CRI-X3 enables programs like DoubleSpace to work on a CD. It's intended for a publisher or for significant internal use, and the licensing is priced accordingly. See http://www.somerset.net/crix3.html. http://www.pgp.com/ has some good encryption software, but none of it works transparently. http://www.c-dilla.com/ has information on CD-Secure 2, which allows publishers to distribute network-licensed or "pay for the parts you need" products, and CD-Compress 2, which provides a way to compress data transparently on production CDs. The web page doesn't have pricing, which suggests that it's expensive. Subject: [3-20] Can I do backups onto CD-R? Yes, but there are limitations. The only program designed for this is published by Adaptec, and appears to be meant for backups smaller than the size of a CD. It doesn't support spanning multiple volumes, but does allow you to do incremental backups by creating linked multisession discs. Of course, it's not really necessary to use special software. Most CD creation programs will allow you to copy arbitrary files onto CDROM, and by using the Joliet standard you can preserve long Win95 filenames. The only disadvantage is that all files are marked as read-only (required by the ISO-9660 spec), so write permission must be re-enabled by hand. (Linux users can su to root, mount the volume as MSDOS FAT, cd to the directory in question, and do "find . -print | xargs chmod +w" to enable write permission for all files in the current directory and in all subdirectories. If you've got the GNU utilities, use "find . -print0 | xargs -0 chmod +w" instead, especially if you're using the "vfat" fs. Of course, if you're a Linux user, you could just use mkisofs without the option that turns off write permission on everything and avoid the problem entirely.) Subject: [3-21] How do I change the CD icon? How does Win95 autoplay work? When preparing a CD for Win95, put a file called "autorun.inf" in the root directory, with entries that look like this: [autorun] open=filename.exe icon=someicon.ico When the CD is placed into a drive with auto-insert notification enabled, it will be shown with the specified icon, and the program named will be launched. (If you turned auto-insert notification off while burning the disc, you may need to reboot before the feature is re-enabled.) Here's a more complicated example: [autorun] open = setup.exe /i icon = setup.exe, 1 shell\configure = &Configure... shell\configure\command = setup.exe /c shell\install = &Install... shell\install\command = setup.exe /i shell\readme = &Read Me shell\readme\command = notepad help\readme.txt shell\help = &Help shell\help\command = winhlp32 help\helpfile.hlp Taking it line by line, this says: - The default AutoPlay command will be "setup /i" - The icon for the CD will be the first icon in setup.exe Four commands will be added to the right-click pop-up menu: - "Configure...", - which will run "setup /c" - "Install...", - which will run "setup /i" (same as auto-run in this case) - "Read Me", - which launches notepad.exe to display "readme.txt" - "Help", - which displays a helpfile with the Win95 help facility For more information: http://www.microsoft.com/devonly/tech/dx3doc/dire1237.htm http://www.gui.com.au/avdf/oct95/samp_autoplay.html A program that will allow you to test autoplay without burning a CD: http://www.connect.net/gstrope/autotest.htm Subject: [3-22] How can I be sure the data got written correctly? The easiest way is to do compare the original with the copy. If the disc was burned from an ISO-9660 image file, programs like Easy-CD Pro 95 will do a comparison of the disc with the original. Another way is to do a recursive file-by-file comparison. Programs that compute CRCs on files and then compare them (meant primarily for virus-checking) will work. Another way is to use the UNIX "diff" utility, which is available for Win95 (along with many other similar utilities) from http://www.reedkotler.com/. If you had copied the contents of C:\MyData onto a CD-R at E:\, you would use: diff -q -r C:\MyData E: The "-q" flag tells it to report if the files differ, but not show what the differences are, and the "-r" flag says to descend into directories recursively. There's a utility called "treediff", available from the Simtel archives (http://www.simtel.com/archive/index.htm), that may also be helpful. Subject: [3-23] How do I copy Karaoke/CD+G discs? The following is an excerpt from the documentation for Jeff Arnold's SNAPSHOT, which is one of the few software packages that can copy CD+G discs: "To backup CD+G discs, you must have one of the following recorders... These are the only recorders that will write the CD+G subcodes. CREATIVE CDR4210 * PANASONIC CW-7501 * PLASMON CDR4240 * SONY CDW-900E YAMAHA All Models * = Records CD+G at 1x speed only The Yamaha CDR200 and CDR400 are the only recorders capable of reading as well as writing CD+G discs. If you do not have one of these models, then you must also have another CDROM device that can read CD+G discs. The following CDROM drives can read CD+G discs... PLEXTOR 4Plex Plus PLEXTOR 8Plex PLEXTOR 12Plex PLEXTOR 12/20Plex SONY 76S (not recommended)" There may be other units that work as readers or writers. Check the documentation from the manufacturer to be sure. Subject: [3-24] How do I copy a CDROM with 3GB of data on it? You don't. The CD doesn't actually have that much data on it. Some CD publishers use a trick where they reference the same spot on the disc several times with overlapping files. If you try to do a file-by-file copy from the disc onto your hard drive, you'll end up with several copies of the same blocks, and more data than can fit on a CDROM. If you want to duplicate a CDROM, you should either use a program meant for the purpose (Adaptec's CD Copier, Jeff Arnold's SNAPSHOT, etc), or extract the data track as a single ISO-9660 image. Some software is more capable of dealing with complex CDs than others, so if you have a particular kind of CD in mind you should check the capabilities of the software before making a purchase. Subject: [3-25] How do I get my CD-R pressed into a real CD? There are a large number of companies that will do modest production runs of pressed CDs, but listing them is beyond the scope of this FAQ. Do a web search on "CD duplication" and "CD replication", or check out http://www.cd-webstore.com/BurningIssues.html (a subscription-based website). Subject: [3-26] How do I make a "concert" CD-R, with tracks but no gaps? Most CD-R drives are capable of doing this. The trick is to find the right software. Jeff Arnold's DAO will let you specify the gap size for each track (down to zero) and set the location of the track and index marks, and you can put each track in a separate file or have the entire recording in a single file. Other programs, like ECDC, are easier to use but less flexible. It isn't necessary to use disc-at-once recording, but it may help. ------------------------------------------------------------------------------ Subject: [4] Problems Problems that arise when burning a CD-R. Subject: [4-1] What does "buffer underrun" mean? It means you have an attractive new coaster for your table. The CD writing process can't be interrupted in mid-session. To prevent this from happening, the makers of CD recorders put a write buffer in the drive, usually 512K or 1MB. Data read from the hard drive, tape, or another CD is stored in the buffer, and pulled out as needed by the recorder. If the recorder requests data from the write buffer, but there's none there, it's called a buffer underrun. The disc is still spinning, but there's no data to write, so the recording process aborts. You can still use the disc with multisession CDROM drives by closing the session and starting another, assuming there's enough space left on the CD, and assuming your pre-mastering software didn't choose to finalize the disc for you. Advice for preventing buffer underruns is scattered throughout this FAQ. A brief summary: - Use a fast, AV-friendly hard drive (i.e. one that doesn't do slow thermal recalibrations). - Record at a slow speed - it takes longer to empty the buffer when recording at 1x. - Don't do anything else with the computer while recording. Don't record from a file server! - Defragment your HD, especially if you're doing on-the-fly recording. - Record from an ISO image file rather than on-the-fly. - Depending on your setup, putting the recorder and your hard drive on separate SCSI controllers may be necessary. - Keep your CD-R cool. Sometimes the drives fail when they overheat. Also watch out for things like anti-virus programs that wake up, virtual memory settings that cause swapping, screen savers that activate during the CD creation process, unusual network activity, and background downloads of data or faxes. One way to check is to run the HD defragmenter in Win95. If it restarts every few seconds, it's because something is hitting the drive. Most Win95-based software recommends turning off Auto Insert Notification. Having this on can interfere with closing sessions or even just inserting discs into the drive. You can disable it by opening the "System" icon in the Control Panel, and selecting "Device Manager". For each item under CDROM, select the device, click on the "Settings" tab, and make sure the "Auto Insert Notification" checkbox is unchecked. [With my setup I get SCSI errors when AIN is off for my CD-R but on for my CDROM, even if the CDROM drive isn't in use at the time.] If you're using WinNT, you can turn it off with the "TweakUI" program available in PowerToys, or by modifying a registry key with Regedit32 (0=disabled, 1=enabled): HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Services \ Cdrom \ Autorun Another helpful tip for Win95 is to limit the size of the file cache, which by default is unrestricted. The procedure is simple: (1) Open the file SYSTEM.INI with a text editor. This file is usually C:\WINDOWS\SYSTEM.INI. (2) Find the section labeled "[vcache]". (3) Add the following lines *after* the "[vcache]" line: minfilecache = 512 maxfilecache = 4096 (4) Save the changes to the file, and reboot. http://www.adaptec.com/support/cdrec/bufunder.html has a comprehensive collection of buffer underrun info. http://www.adaptec.com/support/cdrec/configcdr.html is interesting reading for users with CD-Rs attached to Adaptec SCSI cards. They're pretty far on the conservative side, but if you're having trouble this may help you. An article by Dana Parker entitled "CD-R on the Safe Side: Seven Rules of Successful CD Recording" in the April 1997 issue of Emedia Professional (http://www.onlineinc.com/emedia/EMtocs/emtocapr.html) listed the Seven Habits of Successful CD-R Users: 1. Defragment Your Disk 2. Use a Partition for Staging Input 3. Create a Real Image 4. Test before writing 5. Stabilize Your System for CD-R 6. Shut Down Other Applications 7. After the Burn: Label and Test Subject: [4-2] I can't get long Win95 filenames to work right Typical symptoms can be described like this: - Works fine in Win95 Explorer - Under DOS the directories are visible, but instead of "dirname1" you get "dirname57". Attempting to read them results in errors. - Typing 'cd dirname~102' may fail while 'cd "Long File Names without the ~"' will work. It appears that Win95 and DOS 7.x are simply screwed up. Subject: [4-3] I can't read the multisession CD I just made The SCSI driver needs to believe that the CDROM drive can handle multisession discs. Most likely you will need to update your SCSI drivers before this will work. (This problem was reported with an HP4020i and a Buslogic BT946C controller; if you have an HP drive you should get the c4324hlp.vxd driver from the HP web site. See section 6 for the address.) One possible cause of this problem is writing a multisession disc in MODE-1 format. Some older CDROM drives incorrectly assume that a MODE-1 disc can't be multisession, so they don't look for additional sessions unless it's written in MODE-2 (CD-ROM XA) format. Also, if the final session on the CD isn't closed, standard CD players may become confused (the NEC 6Xi certainly does under Win95). This doesn't mean that the *disc* must be closed, just that the *session* must be closed. (Actually, the NEC 6Xi doesn't like open discs either... sigh.) Subject: [4-4] Write process keeps failing N minutes in There's a couple of possibilities. One is that your data source can't keep up with the CD-R; try using disc-at-once writing from an ISO image with the speed set to 1x. If it seems to be getting worse over time, you may just need to defragment your hard drive. If that fails, a number of people have discovered that the problem is a faulty CD-R unit (similar behavior has been reported on Sony and HP units, which have different mechanisms). You should try 1x writing from a fast source and with different sets of data before contacting the manufacturer, since they will likely tell you to do exactly that anyway. Be sure that there aren't environmental factors creating difficulties. CD-R units are usually built to handle small shocks, but having a set of speakers playing loud music on the same table as a CD-R may cause it to skip, resulting in a failed write. Sonic booms, heavy construction equipment, and nuclear detonations may have similar effects. It's also possible that you simply have a bad batch of media. Try a different type and brand of disc. Some distributors (e.g. dataDisc) will exchange media that's provably defective. Subject: [4-5] Why did my CD-R eject between the "test" and "write" passes? Most CD recorders need to clear their memory between the "test" pass and the "write" pass. For some recorders, the only command that does this is "eject". If the recorder has a tray it just goes out and back in, but if it uses a caddy manual intervention is needed. Some CD-R packages allow you to start the real write pass a few seconds after the test pass has succeeded. They may not disable this even though they know that the disc will have to be ejected. Make sure the option is set to "wait until told to continue." Subject: [4-6] My CDROM drive doesn't like *any* CD-R discs A very simple test is to take a CD that DOES work, copy it, and try both (this ensures that your problems aren't being caused by, for example, a drive that doesn't support multisession CDs). If it fails with both green and gold media, chances are your drive simply doesn't work with CD-R discs. This is rare but not unheard of. In one case, returning the drive for an identical unit solved the problem. While there are stringent specifications for CDs, there are no such specifications for CD audio and CDROM devices. They just have to play the discs. If the disc and the drive are both marginal, you lose. Subject: [4-7] How do I avoid having a ";1" on my ISO-9660 discs? The ISO-9660 standard says the version number (a semicolon followed by a number at the end of every filename) has to be there. Most operating systems simply ignore it, but until recently the Mac didn't, causing some problems. (For the Mac, look at "ISO 9660 File Access" in the System:Extensions folder with Command-I. If the version shown is 5.0 or greater, your system should handle the version numbers just fine. If not, you should update your system software.) "mkisofs" has an option to omit the version number when constructing an ISO-9660 image. Subject: [4-8] I keep getting SCSI timeout errors The advice given to someone with a Philips CDD2000 (same mechanism as HP4020i) with an Adaptec SCSI controller was: - Put the writer on SCSI ID 2 - Turn off Fast SCSI, SCSI Linking, SCSI Disconnect, etc for the writer Subject: [4-9] I'm having trouble writing a complete disc This was happening frequently with the HP4020i running off an AdvanSys SCSI card under Win311 (i.e. WfWG). The solution here was to remove IFSHLP.SYS from the CONFIG.SYS. (IFSHLP.SYS is somehow involved with 32-bit file access and network support, so you may have to disable both of these before disabling IFSHLP. You may have better luck under Win95.) Another user with the same setup found that doing power-up diagnostics and device reset right before burning the CD helped. Subject: [4-10] I get a Write Append Error when the burn is nearly done This seems to happen on Philips CDD2000-based units, such as the HP4020i, usually a short while after the warranty runs out. The most common cause is a spring that weakens with age. After a while, the recorder has trouble writing data onto roughly the last third of the disc. The ways of dealing with this range from minor system changes to the placement of chicken entrails on selected components. Reducing the DMA rate on the AdvanSys SCSI card may help, buying better SCSI cables and checking for proper termination may make a difference, or even powering off and on again right before the burn. One user was told by Philips tech support that if error 50h (write append) occurs, it means the drive has to be returned to the repair center. Other users have been told that the error can occur when attempting to write an empty directory or zero-length file. Under Easy-CD Pro '95, this is reported as error 171-00-50-00 (see the Adaptec web site for a complete list of error codes). If the fault is caused by the worn spring, it may be possible to fix the problem by replacing the spring. This will definitely void your warranty, and you shouldn't even think about trying this unless the only alternative is to throw the drive away. Jonathan Oei posted some details about the process (search for comp.publish.cdrom.hardware, subject "CDD2000 & Spring Fix", on http://www.dejanews.com/). This procedure requires some special tools (mini torx drivers and really fine jeweller's pliers), and involves disassembling much of the drive. If you open up the drive and remove the circuit boards, you will see that the laser writing assembly is moved by a DC stepper motor. The motor has a plastic drive gear that is meshed with a plastic "rack" on the laser. The spring in question is a piece of wire that pushes the rack against the drive gear, so when it weakens the gear slips and the write fails. Replacing the 0.012" wire with a 0.02" diameter wire solves the problem. This question is also covered in the HP4020i FAQ, available at http://www.cd-info.com/CDIC/Technology/CD-R/HP-FAQ.html. Subject: [4-11] Getting errors reading the first (data) track on mixed-mode CD There's a 150-sector postgap at the end of the data track. Some programs deal with this automatically, some don't. If you're getting errors, try subtracting 150 from the total number of sectors to read for that track. Subject: [4-12] My CD-R ejects blank discs immediately There are a few of possibilities, some software and some hardware. It may be that the system is looking at the disc, not finding a TOC (table of contents), and ejecting it as useless. You need to disable this. Under Win95, disable auto insertion for all CDROM devices (see section (4-1)). One user found that reinstalling Win95 helped. On the Mac, you may just need more recent drivers. If that doesn't work, make sure the CD-R drive is perfectly level. Apparently some units are sensitive to being tilted at an angle. Some users have had trouble when a CD-R has been on for a while and has overheated, so if you only have trouble when the machine has been powered on for a while, try putting a small fan above the unit to blow air over it. If nothing helps, there's a strong possibility that the drive is mis- aligned and needs to be serviced. This has been known to happen to drives during shipping. One user reported problems when using the wrong type of caddy. It has to be a Sony-type caddy, which is the kind most commonly found in stores. Subject: [4-13] I'm getting complaints about power calibration The power range of the laser in a CD-R is between 4 and 8 milliwatts. CD-R discs have a section outside the standard recording area called the Program Calibration Area (PCA), which is used to adjust the laser for the brand of media you're using. The error indicates that the CD-R drive is having trouble calibrating the power setting. Try different brands of media, and if that doesn't work you should have the drive checked. Some versions of the firmware for the Philips CDD2000 and HP 4020i will report a power calibration error if you try to do a 1x write after a 4x read. Subject: [4-14] My Adaptec 2940 pauses after finding my CD-R This was observed with a Yamaha CDR-100. The solution is to go into the Adaptec BIOS (hit Ctrl-A during boot), and disable the "support removable disks under BIOS as fixed disks" option and the "boot from CD-ROM" option. Subject: [4-15] I can't see all the files on the CD-R There's a couple of possibilities: either they aren't there, or they're there but you can't see them. Looking at the disc from different machines (e.g. Mac and PC) should give you some idea. Out-of-date versions of MSCDEX have been known to "forget" certain files when browsing a disc. If you're using DOS or are using the "real mode" drivers from within Win95, make sure you're using the most recent version of MSCDEX. Old versions of certain CD creation programs would occasionally omit things when asked to burn a large number of files. These problems haven't been reported for some time, however. If you were burning a multi-session CD, you're on your own. Subject: [4-16] I forgot to use "linked" multisession on my last write A common mistake when burning a multisession CD is to forget to link the files from the previous session into the current one. This results in a CD where you can see the new files but none of the old, unless you have a program that lets you choose which session you look at. If you're using Easy-CD Pro for Win31 or Corel CD Creator, you can load the contents of all the previous sessions, and burn a new session that has all the files you want. This feature isn't currently available in Easy-CD Pro 95, which only allows you to link to one previous session. The files themselves aren't lost forever though: most packages will allow you to extract a track as an ISO-9660 image, and you can use WinImage to pull individual files out of it. One caution: without something like Corel's Session Selector, you may not see the last session on the disc anyway. Some CDROM drives stop looking for sessions after a certain point. Subject: [4-17] I'm getting SCSI errors or corrupted data Good SCSI cables and correct termination are absolutely essential. SCSI bus errors can cause buffer underruns or corrupted data (especially since some vendors ship drives with parity checking disabled). Bertel Schmitt wrote an excellent article on the ins and outs of proper cabling and termination. The article can be found in text form at ftp://ftp.netcom.com/pub/fa/fadden/scsi-trm.txt. Granite Digital, a company that makes high-quality cables and terminators, can be found at http://www.scsipro.com/. If you're using an HP 4020i with the AdvanSys SCSI card, reducing the DMA transfer rate may help. Another thing to try is to do multiple large reads from a CD-ROM disc, and compare the results of each. If the SCSI cable is flaky or the termination isn't done correctly, the problem might affect reads as well as writes. If a file appears to be getting corrupted on the CD-R, try copying it back to the hard drive and then comparing it to the original. If possible, see if the file is missing large chunks or just has sporadic damage throughout. It's possible, though less likely, that it's a defective CD recorder. Subject: [4-18] Why doesn't the copy of an audio CD sound the same? There are actually two questions here, so I've split them into separate sections. The most common problem is that the audio extracted to the hard drive doesn't quite match the original. Subject: [4-18-1] Why doesn't the audio data on the copy match the original? Most problems are due to poor digital audio extraction from the source media. Some CDROM drives will return slightly different data every time an audio track is read. Others, like the Plextor 4Plex, 8Plex, and 12Plex (but not 6Plex), will return the same data every time so long as the source media is clean. The most fundamental problem is that, if the CD is dirty, the error correction may not be able to correct all of the errors. Some drives will interpolate the missing samples, some won't. Another problem most CD-ROM drives face is "jitter". See section (2-15) for details. See also section (3-3) on avoiding clicks in extracted audio, and section (5-5) on which CD-ROM drives are recommended. Subject: [4-18-2] The audio data matches exactly, why do they sound different? [ I have yet to see an authoritative answer to this. ] Suppose you extract the audio track from the copy, and it's an exact binary match of the track you wrote from your hard drive, but the CDs don't sound quite the same. What then? Most people don't notice any difference between originals and duplicates. Some people notice subtle differences, some people notice huge differences. While it's true that "bits are bits", there *are* reasons why CD-Rs may sound different even when the data matches exactly. The manual for the CDD-2000 reportedly states that the drive uses 4x oversampling when playing back pressed CDs, but switches to 1x for CD-R. This affects the quality of the D/A conversion, and can make an audible difference. It has been suggested that the D/A conversion process in the CD player is more susceptible to "jitter" when reading CD-Rs, because the clocking of the bits isn't as precise. A quality CD player will compensate for this automatically. (Note: this kind of jitter is different from the DAE kind of jitter described in section (2-15).) Others have asserted that *any* two CDs, pressed or otherwise, will sound slightly different. Some people believe that audio CDs should be recorded at 1x, while others have asserted that, for various technical reasons, 2x is better. An extremely technical introduction to CD reading is available at http://www.tc.umn.edu/nlhome/g496/eric0139/Papers/paper.html. This may shed some light on why reading audio CDs is difficult. If you are finding noticeable differences, try different media, a different player, and a different recorder. There is some evidence that different brands of media and recorders may work better for audio, but in the end it's a highly subjective matter. Subject: [4-19] Digital audio extraction of a track is slightly off Some recorders don't correctly extract digital audio if the pregap of the first track isn't exactly two seconds. A bug in the firmware causes the drive to start extracting slightly past the start of the track, and stop extracting slightly past the end. This can result in an audible glitch if the music starts at the exact start of the track, and can cause the drive to fail with an error when extracting the last track on the CD. CDs that start at 00:02:32 (0 minutes, 2 seconds, and 32 frames) are surprisingly common. The problem can be worked around manually, by looking at the output of the Jeff Arnold's (freeware) TOC program (available from http://www.goldenhawk.com/) and supplying "/start=" and "/end=" parameters that adjust backward by the number of frames in excess of two seconds. For example, if the first track started at 00:02:32, you would subtract 32 from the starting and ending Logical Block Addresses. A better solution is to use a CDROM drive that doesn't have this problem (and most likely can extract audio more quickly than the CD-R can). The Yamaha CDR-100/102 and the Philips CDD2600 are known to have this problem, though it may get fixed by a firmware update. The Ricoh 6200S reportedly does not return the disc's table of contents correctly for these sorts of discs. ------------------------------------------------------------------------------ [ continued in part 2 of the FAQ ] -- Send UCE to postmaster@localhost (Spam Bait) Send mail to fadden@netcom.com (Andy McFadden) Fight Internet Spam - http://spam.abuse.net/spam/ & news.admin.net-abuse.email Try some spammed toll-free numbers from http://www.clark.net/pub/kfl/toll.html