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[comp.publish.cdrom] CD-Recordable FAQ, Part 1/4

From: fadden@netcom.com (Andy McFadden) Newsgroups: comp.publish.cdrom.hardware,comp.publish.cdrom.software,comp.publish.cdrom.multimedia,comp.answers,news.answers Subject: [comp.publish.cdrom] CD-Recordable FAQ, Part 1/4 Supersedes: <3759c40a.0@news.spies.com> Followup-To: comp.publish.cdrom.hardware Date: 19 Jul 1999 04:25:40 GMT Organization: Netcom Message-ID: <7mu9c4$2u0@dfw-ixnews13.ix.netcom.com> X-NETCOM-Date: Sun Jul 18 11:25:40 PM CDT 1999 Summary: Frequently Asked Questions about CD recorders, CD-R media, CD-RW, and CD premastering. Archive-name: cdrom/cd-recordable/part1 Posting-Frequency: monthly Last-modified: 1999/07/18 Version: 2.13 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, check out the following with a news reader. If you don't have one, you can read news and search for past articles on http://www.dejanews.com/: news:comp.publish.cdrom.hardware news:comp.publish.cdrom.software news:comp.publish.cdrom.multimedia Different HTML versions of this FAQ are available from: http://www.fadden.com/cdrfaq/ http://www.faqs.org/faqs/cdrom/cd-recordable/part1/preamble.html The text version of this FAQ is posted to Usenet and archived in four parts (if you're missing one of the Usenet-posted sections, get it from here): ftp://rtfm.mit.edu/pub/usenet-by-group/comp.publish.cdrom.hardware/ Some translations are available (may be slightly out of date): Italian: http://computer.digiland.it/1346/ French: http://perso.wanadoo.fr/marc.kergomard/gravure.html If a Usenet news posting appears to be cut off at the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.fadden.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] Is the FAQ only available in English? [0-5] Appropriate use of the newsgroups [0-6] I'm having trouble, how do I ask for help? [1] Simple answers to simple questions [1-1] What's CD-R? CD-RW? [1-2] Are they identical to normal CDs? [1-3] Can I create new audio and data CDs? [1-4] Can I use it to copy my CDs? [1-5] How much can they hold? [1-6] Can I just copy files onto a CD-R like I would to a floppy? [1-7] What can you tell me about DVD, DVD-R, DVD-RAM, DVD-RW, etc? [1-8] What's the cheapest recorder and best place to buy media? [1-9] Can I get step-by-step installation and use instructions? [1-10] How do I learn more? [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 CD-ROM 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-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? [2-17] Why don't audio CDs use error correction? [2-18] How does CD-R compare to MiniDisc? [2-19] What does finalizing do? [2-20] How are WAV/AIFF files converted into Red Book CD audio? [2-21] What does MultiRead mean? [2-22] If recording fails, is the disc usable? [2-23] Why do recorders insert 00 bytes at the start of audio tracks? [2-24] How many tracks can I have? How many files? [2-25] Will SCMS prevent me from making copies? [2-26] Is a serial number placed on the disc by the recorder? [2-27] What's a TOC? How does it differ from a directory? [2-28] What's an ISO? A CIF? BIN and CUE? [2-29] Why was 74 minutes chosen as the standard length? [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 get rid of hisses and clicks on audio CDs? [3-4] How do I copy game console discs (e.g. Playstation, Dreamcast) [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 write more than 74 minutes of audio or 650MB of data? [3-8-1] How well do 80-minute CD-R blanks work? [3-8-2] How can I exceed the stated disc capacity ("overburning")? [3-9] How do I put photographs onto CD-ROM? [3-9-1] How do I create a PhotoCD? [3-9-2] How can I set up a photo album on CD-ROM? [3-10] How do I make a CD that will work on a PC or a Mac? [3-11] How do I access 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 movies into video on CD? [3-16-1] How do I create a VideoCD from AVI or MPEG files? [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 Windows autorun work? [3-22] How can I be sure the data was written correctly? [3-23] How do I copy Audio Karaoke/CD+G discs? [3-24] How do I copy a CD-ROM 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 CD without that two-second gap between tracks? [3-27] How can I record RealAudio, MIDI, and MP3 on CD? [3-28] How do I add CD-Text information? [3-29] Can I distribute a web site on a CD-ROM? [3-30] How do I clean my CD recorder? [3-31] Is it better to record at slower speeds? [3-32] Where do I get drivers for my CD recorder? [3-33] Can I copy discs without breaking the law? [3-34] Can CD-Rs recorded at 2x be read faster than 2x? [3-35] How do I make my CD-ROM work on the Mac, WinNT, and UNIX? [3-36] How do I put "hidden tracks" and negative indices on audio CDs? [3-37] Do I need to worry about viruses? [3-38] How do I cover up a bad audio track on a CD-R? [3-39] How do I duplicate this hard-to-copy game? [3-40] How do I erase or format a disc? [3-41] How do I equalize the volume for tracks from different sources? [3-42] How do I make a bit-for-bit copy of a disc? [3-43] How do I put punctuation in CD-ROM volume labels? [4] Problems [4-1] What does "buffer underrun" mean? [4-1-1] What's the deal with Windows Auto-Insert Notification (AIN)? [4-1-2] What's all this about Win95 VCACHE settings? [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 CD-ROM 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] What's the CDD2000 Write Append Error / spring problem? [4-11] Getting errors reading the first (data) track on mixed-mode CD [4-12] My recorder ejects blank discs immediately [4-13] I'm getting complaints about power calibration [4-14] My Adaptec 2940 pauses after finding my recorder [4-15] I can't see all the files on the CD-R [4-16] My multi-session disc only has data from the last session [4-17] I'm getting SCSI errors [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 [4-20] I can't play extracted audio files by double-clicking in Win95 [4-21] I can't read an ISO-finalized packet-written disc [4-22] I'm finding corrupted files on the CD-ROMs I write [4-23] Having trouble playing an audio CD in a home or car player [4-24] Having trouble using a CD-ROM on somebody else's machine [4-25] I can't copy a VideoCD [4-26] The test write succeeds, but the actual write fails [4-27] I can no longer erase a particular CD-RW disc [4-28] Trouble formatting CD-RW discs with DirectCD for Windows 2.0a [4-29] I can't write CD-Rs after installing Windows 98 [4-30] I can't use the copy of a CD-ROM after installing Windows 98 [4-31] The disc I was writing with DirectCD is now unreadable [5] Hardware [5-1] Which CD recorder should I buy? [5-1-1] Yamaha [5-1-2] Sony [5-1-3] Smart & Friendly [5-1-4] Philips [5-1-5] Hewlett-Packard (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 [5-1-30] Dysan [5-1-31] Traxdata [5-1-32] Acer [5-1-33] Waitec [5-1-34] BTC [5-1-35] Caravelle (Sanyo) [5-1-36] Micro Solutions [5-1-37] Pacific Digital [5-2] How long do CD recorders last? [5-3] What kind of PC is recommended? [5-4] What kind of Mac is recommended? [5-5] Which standard CD-ROM 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 SCSI adapter should I use with a CD recorder? [5-7-1] Adaptec - 1510/1522A/1540/1542CF [5-7-2] Adaptec - 2840/2910/2920/2940 [5-7-3] ASUS - SC-200/SC-875 [5-7-4] Diamond - FirePort 20/40/40dual [5-8] Can I use a CD recorder 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 stand-alone audio CD recorders? [5-13] What's firmware? How and why should I upgrade my recorder? [5-14] How well do ATAPI (IDE), parallel-port, and USB recorders work? [5-15] How should I configure my system for an ATAPI CD recorder? [5-16] How important is CD-RW? [5-17] What is an "MMC Compliant" recorder? [5-18] What should I use to record from a UNIX system? [6] Software [6-1] Which software should I use? [6-1-1] Adaptec - Easy-CD, Easy-CD Pro, and Easy-CD Pro MM ("ECD") [6-1-2] Adaptec - CD-Creator ("CDC") [6-1-3] Gear Multimedia - GEAR [6-1-4] Adaptec - Toast [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/Unite - 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 - cdrecord [6-1-21] Prassi Software - CD Rep and CD Right [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 Deluxe ("ECDC") [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 [6-1-33] JVC - Personal Archiver Plus [6-1-34] Adaptec - Jam [6-1-35] VOB - CD-Wizard [6-1-36] Sonic Foundry - CD Architect [6-1-37] Eberhard Heuser-Hofmann - CDWRITE [6-1-38] CeQuadrat - JustAudio! [6-1-39] Digidesign - MasterList CD [6-1-40] Thomas Niederreiter - X-CD-Roast [6-1-41] Jesper Pedersen - BurnIT [6-1-42] Jens Fangmeier - Feurio! [6-1-43] Asimware Innovations - HotBurn [6-1-44] DARTECH, Inc - DART CD-Recorder [6-1-45] Interactive Information R&D - CDEveryWhere [6-1-46] DnS Development - BurnIt [6-1-47] Andreas Müller - CDRDAO [6-1-48] Tracer Technologies - (various) [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] Cyberdyne Software - CD Worx [6-2-6] Paul Crowley CD-ROM Productions - CD-R Diagnostic [6-2-7] DC Software Design - CDRCue Cuesheet Editor [6-2-8] Astarte - CD-Copy [6-2-9] Frank Wolf - CDR Media Code Identifier [6-2-10] Logiciels & Services Duhem - MacImage [6-3] What is packet writing software? [6-3-1] Adaptec - DirectCD [6-3-2] CeQuadrat - PacketCD [6-3-3] SmartStorage - SmartCD for Recording [6-3-4] Gutenberg Systems - FloppyCD [6-3-5] VOB - InstantWrite [6-4] What's UDF? [6-5] Do I want to do packet writing? [6-6] I want to write my own CD recording software [6-6-1] PoINT - CDarchive SDK [6-6-2] Golden Hawk Technology (Jeff Arnold) [6-6-3] Gear Multimedia - GEAR.wrks [6-6-4] VOB - CD-Wizard SDK [6-7] What software is available for doing backups? [6-7-1] Adaptec - Easy-CD Backup [6-7-2] D.J. Murdoch - DOSLFNBK [6-7-3] Dantz - Retrospect [6-7-4] Veritas - Backup Exec [6-7-5] Ghost Software - Ghost [6-7-6] PowerQuest - Drive Image Special Edition for CD-R [6-7-7] Centered Systems - Second Copy [6-7-8] FileWare - FileSync [6-7-9] Novastor - NovaDISK [6-7-10] Adaptec - Take Two [6-7-11] NTI - Backup NOW! [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 of media should I use? [7-5] How long do CD-Rs last? [7-6] How much data can they hold? 650MB? 680MB? [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? [7-10] Where can I find jewel cases and CD sleeves? [7-11] What's "unbranded" CD-R media? [7-12] How do I repair a scratched CD? [7-13] What's this about a Canadian CD-R tax? [7-14] Can I create 80mm (3-inch) CD-singles? [7-15] Where can I find CD-ROM business cards? [8] Net Resources and Vendor Lists [8-1] Information resources [8-2] Magazines and other publications [8-3] Net.vendors [9] Contributors The last-modified date of each section is shown below the Subject line. The date format used is YYYY/MM/DD. The date stamps were added on 1998/04/06, so you won't find any older than that. ------------------------------------------------------------------------------ Subject: [0] Introduction Subject: [0-1] Legal noise (disclaimers and copyrights) (1999/02/09) This FAQ is Copyright (C) 1998-1999 by Andy McFadden, All Rights Reserved. Free distribution of the 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. The plain ASCII text and www.fadden.com HTML versions aren't restricted, but other conversions might be (the content is free, the presentation might not be). Check with the publisher. The date and version number on the FAQ *are* considered part of the content that must not be removed. I occasionally get messages from people who don't realize that the copy they're reading is more than a year and a half old. 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. Visit http://www.clari.net/brad/copymyths.html for a mini-FAQ on copyright laws. Subject: [0-2] What does this FAQ cover? (1999/03/07) 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 CD-ROMs, and helping people find solutions to common problems. The FAQ is heavily biased toward PCs and computer-based recorders, 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 stand-alone audio CD recorders expanding greatly, because they're far simpler to operate than computer-based recorders, and most of the "must know" information about them is more appropriate in an FAQ on stereo systems or studio recording. I do try to address deficiencies in Macintosh coverage. 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. In general, this is a collection of answers to specific questions, not a "how to" guide. I also don't try to track moving targets, like CD recorder firmware versions or software versions unless a specific release is especially interesting. Ditto for which recorders work with which packet-writing solutions. This FAQ does not, and will not, cover DVD, DVD-ROM, DVD-R, DVD-RAM, DVD+RW, or any of the other formats in the ever-expanding DVD morass. Recordable DVD will likely be an altogether different proposition, and will probably require its own FAQ (presumably written by somebody else!). You will not find a lot of detail about "backing up" copy-protected software, or where to find unlock codes or "warez". There are many web sites that explain these matters at length. Subject: [0-3] What's new since last time (1999/07/18) One major change: the way recorders are listed in sections (5-1-x) has been altered. The recorders are now listed one per line, and the speed description format has been changed from "4x6/1MB;RW@2x" to the more common "6x4x2/1MB". Hopefully this will be less confusing, though it may take long-time readers a moment to adjust. I think it's *much* easier to read and update. Added sections (2-28), (2-29), (3-9-2), (5-1-37), (6-1-48), (6-2-10), and (6-7-11). Section (5-13) had some introductory material added. Subject: [0-4] Is the FAQ only available in English? (1999/04/15) There are a few translations available. Italian, by Simone Parca: http://computer.digiland.it/1346/ (formerly at http://users.iol.it/parsi/). French, by Marc Kergomard: http://perso.wanadoo.fr/marc.kergomard/gravure.html. There was a Chinese translation of an early version of the FAQ, but it fell out of date and has since disappeared. French, German, Italian, Portuguese, and Spanish translations can be done through http://babelfish.altavista.digital.com/cgi-bin/translate. This is an automatic language translator that is HTML-aware. It only translates the first part of each document, so it's not entirely helpful if you just want to read a translation, but it may make doing a full translation much easier. (I'm told the translation is pretty good for an automatic translator, but is still pretty rough. I don't want to post a translation that is inaccurate or misleading, so I'm not going to run the FAQ parts through AltaVista automatically.) If you're interested in translating this FAQ, you are welcome to do so, but please respect the amount of work that I and others have put into it. Don't strip out sections, remove author attributions, or hide the revision date of the document. I don't think the terms in section (0-1) are terribly restrictive. If, for whatever reason, you can't keep up with every update of the English version, that's fine; all I ask is that you include a link to the www.fadden.com version, so that the current information is easily locateable. (Some commonly updated things, like the list of recorders in section (5-1), don't need much translation.) If you don't want to translate a particular section, just leave it in English. If you want to start with an HTML version, use the pages from http://www.fadden.com/cdrfaq/. If you prefer to do the translation on a text document, and you're converting to an iso-latin language, the "faq2html" converter that I use can be found in the "downloads" section on http://www.fadden.com/. If you do a translation, let me know and I'll put the URL here. Subject: [0-5] Appropriate use of the newsgroups (1998/04/06) 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 CD-ROMs, 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 CD-ROM drives. Some related newsgroups are: news:comp.sys.ibm.pc.hardware.cd-rom news:comp.sys.ibm.pc.hardware.storage news:comp.sys.ibm.pc.hardware.systems news:alt.comp.periphs.cdr news:comp.periphs.scsi news:alt.cd-rom news:linux.apps.cdwrite news:comp.publish.cdrom.software is for discussions about software used to prepare material for and create CDs and CD-ROMs. 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 CD-ROMs. 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-ROM software or CDs: CD recorders 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 CD-ROM 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. (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. (7) Binaries: as with most Usenet newsgroups, posting binary files (large or small) is inappropriate. If you want to make a binary file available to Usenet readers, send it to an appropriate alt.binaries newsgroup, and just post a pointer to it in the other group(s). 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: [0-6] I'm having trouble, how do I ask for help? (1998/04/06) The first thing to do is look at the web pages for the products you're using. Sometimes there will be software or firmware updates, or pages with information on common problems. Scanning through news archives on servers like www.altavista.digital.com or www.dejanews.com will often turn up relevant material. If you don't find anything, calling or sending an e-mail message to the technical support department for the product that is giving you trouble is a good second step. If you want to contact other users, posting a message to one of the Usenet newsgroups is a reasonable thing to do. You will get faster, more accurate responses to questions if you include enough detail in your mail message or news posting. For most problems having to do with recording, you need to specify: (1) Platform. PC, Mac, Sun, whatever. (2) Operating system, with version. Win95, Win98, WinNT3.5, WinNT4, etc. Mention any interesting goodies, e.g. IE4 Active Desktop. (3) CD-R brand, model, and firmware revision, e.g. "Yamaha CDR-102 v1.00". (4) Other relevant hardware details. If the recorder comes in SCSI and IDE or parallel-port versions, specify which you were using, and what sort of interface was used (e.g. "SCSI, Adaptec 2940U"). For SCSI device problems, listing the other devices on the chain may help. (5) Software in use, including version numbers, e.g. "Easy-CD Pro 95 v1.2". (6) Brand of media. Be sure to specify CD-R or CD-RW. (7) What were you trying to do? What specific steps did you take to go about it? Have you tried anything to correct the problem, and if so, what were the results? (8) Specific error messages seen. Write down *exactly* what it says, add any numeric error codes along with it. Be sure to write down what it *said*, not what you think it *meant*. Add your interpretation of events only after you've gotten all the details down. Try to include any details which you think might be relevant. Take the time to organize your report so that it is easy to understand. And PLEASE check this FAQ for the answers first! Much of the volume on the newsgroups is from people whose questions are already answered here. ------------------------------------------------------------------------------ Subject: [1] Simple answers to simple questions (1998/04/06) These are intended to be brief (if somewhat incomplete) answers to basic questions. More detailed information can be found later in the FAQ. For example, section (1-5), "How much can they hold?", is answered in far more detail in section (7-6). Subject: [1-1] What's CD-R? CD-RW? (1999/06/25) CD-R is short for "CD-Recordable". Recordable CDs are WORM (Write Once, Read Multiple) media that work just like standard CDs. The advantage of CD-R over other types of optical media is that you can use the discs with a standard CD player. The disadvantage is that you can't reuse a disc. A related technology called CD-Rewritable (CD-RW) allows you to erase discs and reuse them, but the CD-RW media doesn't work in all players. CD-Rewritable drives are able to write both CD-R and CD-RW discs. Subject: [1-2] Are they identical to normal CDs? (1998/10/07) The CDs you buy in a store are pressed from a mold. CD-Rs are burned with a laser. They may look different (often green, gold, or blue instead of silver), they're less tolerant of extreme temperatures and sunlight, and they're more susceptible to physical damage. Whether CD-Rs or pressed CDs last longer is difficult to answer. While they're not physically identical, they work just the same. Some CD players and CD-ROM drives aren't as good at reading CD-R and CD-RW discs as they are at reading pressed CDs, but by and large they work just fine. By the way, you can't write data onto pressed discs. Buying a bunch of old CDs in the hopes of writing new stuff onto them is a bad idea. You have to buy blank CD-R or CD-RW media. Subject: [1-3] Can I create new audio and data CDs? (1998/05/16) Yes. You can create CD-ROMs from data on your hard drive, and you can create new audio CDs from anything you can record into a WAV or AIFF sound file. With an audio-only CD-Recorder, which hooks up to your stereo system instead of your computer, you can record directly from CD, cassette, DAT, or whatever. The CD-ROMs you produce will play in ordinary CD-ROM drives, and the audio CDs you create will work in your home or car CD player. Writing to CD-Rs and CD-RWs requires a special drive. You can't write CDs with an ordinary CD-ROM drive. Subject: [1-4] Can I use it to copy my CDs? (1998/04/06) Yes, both audio and data CDs can be duplicated. You can even create audio CDs that are compilations of other audio CDs (perhaps a personal "best of" disc). Bear in mind that most CDs are protected by copyright laws. Subject: [1-5] How much can they hold? (1998/05/16) About 74 minutes of audio, or about 650MB of data. Subject: [1-6] Can I just copy files onto a CD-R like I would to a floppy? (1998/04/06) Yes and no. The process can be a bit more involved than that, and requires special software that (usually) comes bundled with the drive. With "packet writing" software, and a recorder that supports it, you can treat a CD-R or CD-RW disc like a floppy. Generally speaking, you can only write to each part of the disc once, so deleting files doesn't gain any space. There are other limitations as well. With more traditional software -- necessary if you want the broadest possible compatibility -- you usually end up writing everything to the disc all at once. When you're doing the writing you can't interrupt the drive, and you can't reclaim the space you've used. If you want to write your files in smaller bunches, you lose a fair bit of space every time you stop and start again. Subject: [1-7] What can you tell me about DVD, DVD-R, DVD-RAM, DVD-RW, etc? (1998/12/14) Nothing. This FAQ is about CD-R and CD-RW, and only crosses over into DVD when the two technologies rub up against each other. To learn more about DVD, try http://www.unik.no/~robert/hifi/dvd/ (http://www.multimania.com/abela/DVD/DVDfaq.html if you prefer French). Subject: [1-8] What's the cheapest recorder and best place to buy media? (1999/02/07) I don't know. I don't track prices. There are web sites dedicated to finding the lowest prices, and you can do a little research with a web browser, starting perhaps with the vendors listed in section (8-3). Subject: [1-9] Can I get step-by-step installation and use instructions? (1999/02/07) Yes, from the manual that comes with your recorder and software. There's no information of this type in the FAQ because there are far too many permutations of hardware and software, and the instructions would have to be updated with every new release of the software. Subject: [1-10] How do I learn more? (1998/05/16) This FAQ contains a great deal of information, but it's geared toward answering specific questions rather than providing a general education. Some of the other net resources are more like a tutorial than a Q&A list, and may provide a better starting point. Mike Richter has a primer on CD-R at http://resource.simplenet.com/. Octave's CD-Recordable Handbook is available in HTML from http://www.octave.com/library/ricoh/cdrhandbook.html. Adaptec has a lot of information at http://www.adaptec.com/cdrec/. I get a lot of questions about digital audio extraction that are answered at http://www.tardis.ed.ac.uk/~psyche/cdda/. ------------------------------------------------------------------------------ Subject: [2] CD Encoding (1998/04/06) CD fundamentals. Subject: [2-1] How is the information physically stored? (1998/08/16) 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." Your basic CD-R is layered like this, from top to bottom: [optional] label [optional] scratch-resistant and/or printable coating UV-cured lacquer Reflective layer (24K gold or a silver-colored alloy) Organic polymer dye Polycarbonate substrate (the clear plastic part) Yes, it's real gold in "green" and "gold" CDs, but if you hold a CD-R up to a light source you'll notice that it's thin enough to see through (the gold layer is between 50 and 100nm thick). Something to bear in mind is that the data is closest to the label side of the CD, not the clear plastic side that the data is read from. If the CD-R doesn't have a hard top coating such as Kodak's "Infoguard", it's fairly easy to scratch the top surface and render the CD-R unusable. 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. Discs are written from the inside of the disc outward. On a CD-R you can verify this by looking at the disc after you've written to it. The spiral track 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. The construction of a CD-RW is different: [optional] label [optional] scratch-resistant and/or printable coating UV-cured lacquer Reflective layer Upper dielectric layer Recording layer (the part that changes form) Lower dielectric layer Polycarbonate substrate (the clear plastic part) See the net references section for pointers to more data (especially http://www.cd-info.com/). http://www.pc.be.philips.com/cdrw/general.html has some nice pictures, as does http://www.nswc.navy.mil/cosip/nov97/cots1197-2.shtml. Subject: [2-2] What is XA? CDPLUS? CD-i? MODE1 vs MODE2? Red/yellow/blue book? (1999/02/07) See the net references section for pointers. The "CD Related Info" section on http://www.cdarchive.com/ has useful data, as does http://www.cd-info.com/ and the alt.cd-rom FAQ pages. 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) CD-ROM/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 (evolved from High Sierra format) Rock Ridge = extensions allowing long filenames and UNIX-style symlinks CD-RFS = Sony's incremental packet-writing filesystem CD-UDF = industry-standard incremental packet-writing filesystem CD-Text = Philips' std 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.emediapro.net/AprEM/parker4.html. See http://www.licensing.philips.com/ if you want to buy copies of the standards. They're not cheap! 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? (1998/12/20) 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". VideoCD is different from CD-Video. CD-V is an analog format, like LaserDisc, and the video can't be viewed with a CD-ROM drive. Subject: [2-4] How does CD-ROM copy protection work? (1999/02/19) 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 CD-ROM 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 game consoles, where the drive mechanism and firmware are well defined. A less sophisticated but nonetheless 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. An overburned 80-minute blank (sections (3-8-1) and (3-8-2)) can hold about as much as you can reliably fit on a disc anyway. 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)). Another method gaining popularity is non-standard discs with a track shorter than 4 seconds. Most recording software, and in fact some recorders, will either refuse to copy a disc with such a track, or will attempt to do so and fail. A protected application would check for the presence and size of the track in question. Some recorders may succeed, however, so this isn't foolproof. (In one case, a recorder could write tracks that were slightly over three seconds, but refused to write tracks that were only one second. There may be a limit below which no recorder will write.) Putting multiple data tracks interleaved with audio tracks on a CD will confuse some disc copiers. Sometimes the copy of a disc will have a different volume label. This usually only happens with file-by-file copies, not disc image copies, so checking the disc name is marginally useful but not very effective. Modifying the TOC so that the disc appears to be larger than it really is will convince some copy programs that the source disc is too large. The Laserlok system from http://www.diskxpress.com/ claims to be able to prevent unauthorized disc duplication at a low cost. (VOB's CD-Wizard, listed in section (6-1-35), claims to be able to copy them.) 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. Sony DADC is promoting a simliar product called Securom. Some information is at http://www.sonydadc.com/hotnews/secu_fra.htm. Yet another variant is C-Dilla's SafeDisc[tm]; see http://www.c-dilla.com/ for more. All of the above applies to CD-ROM discs. There is no way to copy protect an audio CD and still have it be playable in an audio CD player. See also the "CD Protections" frame on http://www.esware.net/empire/hardware/cdrom/cd.htm. A separate but related issue is "counterfeit protection", where the publisher wants to make it easy to detect mass-produced duplicates. An example of this is Microsoft's placement of holograms on the hub of their recent CD-ROMs. Subject: [2-5] What's a multisession disc? (1999/06/05) 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 CD-ROM 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 CD-ROM 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 CD-ROM 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. (Some audio CD players do seem to be able to recognize all of the tracks on a multisession audio disc. Most do not. The only way to know for sure is to try and see. If you are planning to give an audio CD you create to others, it would be wise to write it in a single session.) Note that mixing MODE-1 (CD-ROM) and MODE-2 (CD-ROM/XA) sessions on a single disc isn't allowed. You could create such a thing, but many CD-ROM drives will have a hard time recognizing it. See also http://www.adaptec.com/support/faqs/multisession.html, which goes into more depth. Discs written with packets are an entirely different story. See section (6-3). Subject: [2-6] What are subcode channels? (1998/04/06) 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. See http://www.ee.washington.edu/conselec/CE/reports/Group.1/matt_page_individual/subcode.html. 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? (1999/02/06) At present, not many manufacturers use them, and not all devices can read all of the fields. Programs that identify audio CDs automatically compute an ID based on the quantity and lengths of the audio tracks. http://www.cddb.com/ has a collection of CD information. Subject: [2-8] How long does it take to burn a CD-R? (1998/04/06) 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? (1998/06/14) There are two basic ways of writing to a CD-R. Disc-at-once (DAO) 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 (TAO) 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. Because the laser is turned off and on for every track, the recorder leaves a couple of blocks between tracks, called run-out and run-in blocks. If done correctly, the blocks will be silent and usually unnoticeable. CDs with tracks that run together will have a barely noticeable "hiccup". Some combinations of software and hardware may leave junk in the gap, resulting in a slight but annoying click between tracks. 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 be difficult or impossible to make identical backup copies of some kinds of discs without using disc-at-once mode (e.g. copy-protected PC games). Also, some CD mastering plants may not accept discs recorded in track-at-once mode, because the gaps between tracks will 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? (1998/12/20) 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 Mac, you might instead use an HFS filesystem for the data track. You can create the image with Mac CD recording software, or create it as a DiskCopy image file and then burn the data fork under a different OS. The DiskCopy method doesn't seem to allow you to create bootable CD-ROMs though.) 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? (1999/04/11) There are subcode flags for each track: Data If set, the track contains data; if not, the track contains audio. Digital Copy Permitted Used by SCMS. Set to allow copies, clear to prevent them. 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 two are rarely used. Subject: [2-12] How does CD-RW compare to CD-R? (1998/12/20) 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. Other than that, they are used just like CD-R discs. CD-RW drives use phase-change technology. Instead of creating "bubbles" and deformations in the recording dye layer, the state of material in the recording layer changes from crystalline to amorphous form. The different states have different refractive indicies, and so can be optically distinguished. These discs are not writable by standard CD-R drives, nor readable by most older CD readers (the reflectivity of CD-RW is far below CD and CD-R, so an Automatic Gain Control circuit is needed to compensate). All CD-RW drives can write to CD-Rs, and most new CD-ROM drives are expected to support CD-RW media. (Reports have indicated that CD-RW discs don't always read at full speed on some drives, however.) A few older audio CD players and many new ones can handle CD-RW discs, but many can't. If you want to create audio CDs on CD-RW media, make sure that your player can handle them. 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. CD-RW media is much more expensive than CD-R. This has been improving, but is still a factor in purchase decisions. There is a limit to the number of times an area of the disc can be rewritten, but that number is relatively high (the Orange Book requires 1000, but some manufacturers have claimed as much as 100,000). For an *excellent* description of the technology, see http://www.emediapro.net/cdrompro/0996CP/bennett9.html A technical discussion along with some handy drawings and graphs is available from http://www.pc.be.philips.com/cdrw/general.html. Some interesting articles on CD-RW - including an editorial critical of the new technology - can be found at: http://www.emediapro.net/JanEM/news1.html#erase http://www.emediapro.net/FebEM/writer2.html http://www.emediapro.net/AprEM/parker4.html#bennett If you're trying to decide if you want a drive that supports CD-RW, see section (5-16). Subject: [2-13] Can DVD drives read CD-Rs? (1998/07/28) 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 players 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. Look for the MultiRead logo, which indicates that the DVD player can read all existing CD formats, including CD-ROM, CD-DA, CD-R and CD-RW. [ I verified that the Sony DVP-S3000 can read CD-R media, though the manual didn't say anything about them. It plays audio CDs and VideoCDs off CD-R just fine. I'm told that the Sony models include two lasers -- Dual Discrete pickup -- but most of the others don't. I'm not planning on starting a compatibility list, so if you plan to buy a DVD player and CD-R compatibility is important, bring an audio or VideoCD CD-R with you to the store and try to play it. ] Subject: [2-14] Should I wait for DVD-R? (1999/06/05) Probably not. The recorders are still very expensive, and the format wars have made a mess of things. An example: http://www.electroweb.com/product/hard.htm was, as of early February '98, selling a Pioneer CDVR-S101 DVD-Recordable Drive for US$18K. In June '99, the same site had a Pioneer CDVR-S201 for US$5100. The prices on hardware and software will eventually reach consumer levels. As mentioned in section (0-2), this FAQ will not be expanding to cover DVD recorders. Writers for formats like DVD-RAM are available for less, but may not be compatible with current DVD players. Subject: [2-15] What are "jitter" and "jitter correction"? (1998/04/06) The first thing to know is that there are two kinds of jitter that relate to audio CDs. The usual meaning of "jitter" refers to a time-base error when digital samples are converted back to an analog signal; see http://www.digido.com/jitteressay.html for a discussion. The other form of "jitter" is used in the context of digital audio extraction from CDs. This kind of "jitter" causes extracted audio samples to be doubled-up or skipped entirely. (Some people will correctly point out that the latter usage is an abuse of the term "jitter", but we seem to be stuck with it.) "Jitter correction", in both senses of the word, is the process of compensating for jitter and restoring the audio to its intended form. This section is concerned with the (incorrect use of) "jitter" in the context of digital audio extraction. 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 each block. The inaccuracy is small, but if the system doing the extraction has to stop, write data to disk, and then go back to where it left off, it won't be able to seek to the exact same position. As a result, the extraction process will restart a few samples early or late, resulting in doubled or omitted samples. These glitches often sound like tiny repeating clicks during playback. 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 data FIFO alone. This is why it's so much easier to pull single blocks off of a CD-ROM. 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, e.g. 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? (1999/02/06) 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. http://www.cdpage.com/ has a CD-Recordable museum on their web page. Subject: [2-17] Why don't audio CDs use error correction? (1999/02/06) Actually, they do. It is true that audio CDs use all 2352 bytes per block for sound samples, while CD-ROMs use only 2048 bytes per block, with most of the rest going to ECC (Error Correcting Code) data. The error correction that keeps your CDs sounding the way they're supposed to, even when scratched or dirty, is applied at a lower level. All of the data written to a CD uses CIRC (Cross-Interleaved Reed-Solomon Code) encoding. Every CD has two layers of error correction, called C1 and C2. C1 corrects bit errors at the lowest level, C2 applies to bytes in a frame (24 bytes per frame, 98 frames per block). In addition, the data is interleaved and spread over a large arc. (This is why you should always clean CDs from the center out, not in a circular motion.) If there are too many errors, the CD player will interpolate samples to get a reasonable value. This way you don't get nasty clicks and pops in your music, even if the CD is dirty and the errors are uncorrectable. Interpolating adjacent data bytes on a CD-ROM wouldn't work very well, hence the need for additional ECC and EDC (Error Detection Codes). See http://www.cdpage.com/dstuff/BobDana296.html for an overview of error correction from the perspective of media testing. If you really want to get into the gory technical details, try http://www.ee.washington.edu/conselec/CE/kuhn/cdmulti/95x7/iec908.htm. Subject: [2-18] How does CD-R compare to MiniDisc? (1998/05/05) MiniDiscs, or MDs, are small (64mm) discs that hold about 140MB of data or 160MB of audio. By using sophisticated compression techniques they are able to compress audio by a 5:1 ratio, allowing a capacity of 74 minutes with little or no audible difference in quality. As with CD recorders, there are MD recorders that connect to your computer and MD recorders that connect to your stereo. There are stamped MDs that are similar to CDs in construction, and rewritable MDs that use magneto-optical technology. Audio MD recorders are generally more convenient than stand-alone audio CD recorders, because the playback mechanism allows a more flexible layout of audio data, so it's possible to delete a track from the middle of the MD and then write a longer one that is recorded in different places across the disc. The current generation of MD technology is unlikely to replace CD-R or DAT, however, because the lossy compression employed is disdained by audio purists. MD is more often positioned as a replacement for analog cassette tape, which it matches in portability and recordability, and surpasses in durability and its ability to perform random accesses. Computer-based MD recorders can write data, but may not be able to record audio. Check the specifications carefully. A wealth of information is available from http://www.minidisc.org/. If you want to transfer CD to MD or MD to CD-R, check the FAQ there for information about digital transfers (currently item #37). Subject: [2-19] What does finalizing do? (1999/06/05) A disc that you can add data to is "open". All data is written into the current session. When you have finished writing, you close the session. If you want to make a multisession disc, you open a new session at the same time. If you don't open a new session then, you can't open one later, which means that it's impossible to add more data to the CD-R. The entire disc is considered "closed". The process of changing a session from "open" to "closed" is called "finalizing", "fixating", or just plain "closing" the session. When you close the last session, you have finalized, fixated, or closed the disc. A single-session disc has three basic regions: the lead-in, which has the Table of Contents (or TOC); the program area, with the data and/or audio tracks; and the lead-out, which doesn't have anything meaningful in it. An "open" disc doesn't yet have the lead-in or lead-out written. If you write data to a disc and leave the session open, the TOC -- which tells the CD player or CD-ROM drive where the tracks are -- is written into a separate area called the Program Memory Area, or PMA. CD recorders are the only devices that know to look at the PMA, which is why you can't see your data in an open session on a standard playback device. CD players won't find any audio tracks, and CD-ROM drives won't see a data track. When the session is finalized, the TOC is written in the lead-in area, enabling other devices to recognize the disc. (Something to try: write an audio track to a blank CD, and leave the session open. Put the disc in a CD player. Some players will deny the existence of the disc, some will spin the disc up to an incredible speed and won't even brake the spindle when you eject the disc, others will perform equally random acts. The TOC is important!) If you close the current session and open a new one, the lead-in of the closed session will include a link to the lead-in of the next. The CD player in your car or stereo system doesn't know about chasing from one lead-in to the next, so it can only see tracks in the first session. Your CD-ROM drive, unless it's broken or fairly prehistoric, will know about multisession discs and will happily return the first session, last session, or one somewhere in between, depending on what the OS tells it and what it is capable of. Some CD-ROM drives, notably certain NEC models, are finicky about open sessions, and will gag when they try to read the lead-in from a still-open session. They follow the chain of links in the lead-ins of each session, but when they get to the last, they can't find a valid TOC and become confused. Even though these drives support multi-session, they require that the last session be closed before they will read the disc successfully. Fortunately, most drives don't behave this way. If you use disc-at-once recording, the lead-in is written at the very start of the process, because the contents of the TOC are known ahead of time. With most recorders there is no way to specify that an additional session should be added, so creating a multisession disc with DAO recording isn't generally possible. If you're using Win95 or WinNT, the Auto Insert Notification feature will "discover" the CD-R as soon as the TOC is written. This usually causes the write process to fail. Many of the current CD recording software packages will automatically disable AIN for this reason. In track-at-once mode, it will fail during finalization; in disc-at-once mode, it will fail near the beginning of the write process. In both cases, test writes will succeed, because the TOC doesn't get written during a test pass. Packet-written discs follow the same rules with regard to open and closed sessions, which is why they have to be finalized before they can be read on a CD-ROM drive. The "Packet Writing - Intermediate" document in the primer at http://resource.simplenet.com/primer/primer.htm goes into a little more detail on this subject. There are gory details beyond what is written here. For example, the lead-in on a CD-R actually has a pre-recorded TOC that specifies physical parameters of the recording layer, such as required laser recording power, and information about the disc, like how many blocks can be written. You don't usually need to worry about such things though. Subject: [2-20] How are WAV/AIFF files converted into Red Book CD audio? (1999/05/06) There is absolutely nothing special about the audio data encoded on a CD. The only difference between a "raw" 44.1KHz 16-bit stereo WAV file and CD audio is the byte ordering. It isn't necessary to convert a WAV or AIFF file to a special format to write to a CD, unless you're using some proprietary coding (like MP3 compression) that doesn't have a system-recognized codec. Similarly, you don't have to do anything special to audio extracted from a CD. It's already in a format that just about anything can understand. Just put your audio into the correct format -- 44.1KHz, 16-bit, stereo, uncompressed (a/k/a PCM) -- and the software you use to write CDs will do the rest. All of the fancy error correction and track indexing stuff happens at a lower level. Some people get confused by programs (such as Win95 Explorer) that show ".CDA" files. This is just a convenient way to refer to the audio tracks. It's not a file format unto itself. You can't drag-and-drop CD audio tracks unless you're using software that understands what you're trying to do, such as a CD recording program or Plextor's "AudioFS". Subject: [2-21] What does MultiRead mean? (1998/07/28) 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://www2.osta.org/osta/html/press/pr150797.html. The presence of this logo on a CD-ROM drive does *not* mean that the drive can read DVD. Subject: [2-22] If recording fails, is the disc usable? (1998/07/31) That depends on what was being recorded, how it was being recorded, and how far along in the process things were. If it failed while writing the lead-in, before any data was written, the disc probably isn't usable. Sony drives have a "repair disc" option that forcefully closes the current session, which would allow you to add extra data in a second session on the disc, but most recorders will refuse to touch a disc that's in a partially-written state. Failures when finalizing the disc may be correctable. Sometimes the TOC gets written before the failure, and the disc can be used as-is. Sometimes you can use a "finalize disc" option from a program menu that will do the trick. Other times the recorder will refuse to deal with a partially-finalized disc, and you're stuck. Failures in the middle of writing result in a CD-ROM that probably isn't worth trusting. Some of the data will be there, some won't. The directory for the disc may show more files than are actually present, and you won't know which are actually there until you try to read them. Audio CDs recorded in disc-at-once mode are a special case. Because the TOC is written up front, the disc is readable in a standard CD player even if the write process doesn't finish. You will be able to play the tracks up to the point where the recording failed. If you were using a packet writing program like DirectCD, the experiences of people on Usenet suggest that you are either 100% okay or 100% screwed. The ScanDisk utility included with DirectCD 2.5 may help though. Subject: [2-23] Why do recorders insert 00 bytes at the start of audio tracks? (1998/08/14) This phenomenon is familiar to users who have attempted to extract digital audio from a CD-R. Very often the result of copying an audio CD is an exact copy of the original audio data, but with a few hundred zero bytes inserted at the front (and a corresponding number lost off the end). Since this represents the addition of perhaps 1/100th of a second of silence at the start of the disc, it's not really noticeable. The actual number of bytes inserted may very slightly from disc to disc, but a given recorder usually inserts about the same number. It's usually less than one sector (2352 bytes). According to a message from a Yamaha engineer, the cause of the problem is the lack of synchronization between the audio data and the subcode channels, much like the "jitter" described in section (2-15). The same data flow problems that make it hard to find the start of a block when reading also make it hard to write the data and identifying information in sync. According to the engineer, no changes to the firmware or drive electronics can fix the problem. Making copies of copies of audio CDs would result in a progressively larger gap, but it's likely to be unnoticeable even after several generations. Subject: [2-24] How many tracks can I have? How many files? (1999/03/07) You can have up to 99 tracks. Because the track number is stored as a two-digit decimal number starting with "01" (BCD encoded, in case you were wondering), it's not possible to exceed this. The maximum number of files depends on the filesystem you're using. For ISO-9660, you can (in theory) have as many as you want. In practice, DOS or Windows will treat the disc internally as a FAT16 filesystem, so you are limited to about 65,000 files if you want broad compatibility. Subject: [2-25] Will SCMS prevent me from making copies? (1999/04/11) SCMS is the Serial Copy Management System. The goal is to allow consumers to make a copy of an original, but not a copy of a copy. Analog recording media, such as audio cassettes and VHS video tape, degrades rather quickly with each successive copy. Digital media doesn't suffer from the same degree of generation loss, so the recording industry added a feature that has the same net effect. SCMS will affect you if you use consumer-grade audio equipment. Professional-grade equipment and recorders that connect to your computer aren't restricted. See section (5-12) for more about the differences between these types of devices. The system works by encoding whether or not the material is protected, and whether or not the disc is an original. The encoding is done with a single bit that is either on, off, or alternating on/off every five frames. The value is handled as follows: - Unprotected material: copy allowed. The data written is also marked unprotected. - Protected material, original disc: copy allowed. The data written will be identified as a duplicate. - Protected material, duplicate: copy not allowed. There are hardware "SCMS strippers", primarily used in conjunction with a DAT deck, that strip the SCMS bits out of an S/PDIF connection. Some have found that these introduce unacceptable artifacts into the audio. It's possible to "wash" the audio by converting it to and from analog format, but again the quality will suffer. If you're using a consumer audio CD recorder, SCMS will prevent you from making copies of copies of protected material. It will not prevent you from making a copy of an original disc you have purchased, and it won't stop you from copying unprotected discs. Related sites: http://www.oade.com/tapers/scms1.html http://www.sfb.net/scms.htm http://www.xs4all.nl/~jacg/dcc-faq.html Subject: [2-26] Is a serial number placed on the disc by the recorder? (1999/07/12) In general, no, but it appears that some of the newer stand-alone audio CD recorders write one. See http://www.sfb.net/scms.htm for a blurb about RID (Recorder Unique Identifier). Windows will show something like "Volume Serial Number is 4365-0FED". There does not appear to be any way to control this. Some have suggested that the serial number is generated based on data found on the disc, similar to the way that audio CDs can (mostly) be uniquely identified by the number and durations of the tracks. Subject: [2-27] What's a TOC? How does it differ from a directory? (1999/06/05) The TOC (Table Of Contents) identifies the start position and length of the tracks on a disc. The TOC is present on all CDs. If it weren't, the disc would be unreadable on a CD player or CD-ROM drive. (Section (2-19) has some more details.) A "directory" is a list of files. If you're a Mac user, you're probably used to the term "folder". It's part of a filesystem, such as the ISO-9660 or HFS filesystem present on most CD-ROMs. Audio tracks don't have files, so they don't have directories either. There's nothing stopping you from writing a FAT16 or Linux ext2 filesystem directly onto a CD-ROM. Whether or not you can read such a disc is a different matter. (The Linux "mount" command should allow you to mount just about anything read-only, but Windows may not be so willing.) The CD specification defines the TOC, and there are well-defined standards for certain filesystems, but [AFAIK] nothing in the CD spec requires that you fill a data track with a certain kind of data. Subject: [2-28] What's an ISO? A CIF? BIN and CUE? (1999/07/12) In common use, an "ISO" is a file that contains the complete image of a disc. Such files are often used when transferring CD-ROM images over the Internet. Depending on who you're talking to, "ISO" may refer to all disc image files or only certain kinds. Going by the more restrictive definition, an "ISO" is created by copying an entire disc, from sector 0 to the end, into a file. Because the image file contains "cooked" 2048-byte sectors and nothing else, it isn't possible to store anything but a single data track in this fashion. Audio tracks, mixed-mode discs, CD+G, multisession, and other fancy formats can't be represented. To work around this deficiency, software companies developed their own formats that *could* store diverse formats. Corel developed CIF, which is still in use by Adaptec's Easy CD Creator. (What does CIF mean? Nobody knows, though "Corel Image Format" is as good a definition as any.) Jeff Arnold's CDRWIN created them as "BIN" files, with a separate "cue sheet" that described the contents. A ".ISO" file that contains an image of an ISO-9660 filesystem can be written to a CD-ROM, mounted as a device with the Linux "loopback" filesystem, copied to a hard drive partition and mounted under UNIX, or viewed with WinImage (section (6-2-2)). There is no guarantee, however, that a ".ISO" file contains ISO-9660 filesystem data. And it is quite common to hear people refer to things as "ISO" which aren't. (The rest of this section is a philosophical rant, and can safely be skipped. This is intended to be more illustrative than factual, and any relation to actual events is strictly coincidental.) The term "ISO" is ostensibly an abbreviation of "ISO-9660 disc image", which is itself somewhat suspect. ISO-9660 is a standard that defines the filesystem most often used on CD-ROM. It does not define a disc image format. "ISO-9660 filesystem image" would be more appropriate. When you capture or generate a CD-ROM image, you have to call it something. When a CD-ROM was generated from a collection of files into an ISO-9660 filesystem image, it was written into a file with an extension of ".ISO". This image file could then be written to a CD-ROM. As it happens, the generated image files were no different in structure from the images that could be extracted from other CD-ROMs, so to keep things simple the extracted disc images were also called ".ISO". (Some programs used the more appropriate ".IMG", but unfortunately that was less common.) This meant that, whether you extracted a data track from a disc written with the HFS filesystem or the ISO-9660 filesystem, it was labeled ".ISO". This makes as much sense as formatting a 1.4MB PC floppy for HFS, creating an image, and calling it a "FAT16 disk image" because such floppies are usually formatted with FAT16. It didn't really matter though, because no matter what was in the file, the software used the same procedure to write it to CD-R. As a result of this filename extension convention, any file that contained a sector-by-sector CD-ROM image was referred to as an "ISO file". When CD recorders hit The Big Time and more people started swapping image files around, the newcomers didn't know that there was a distinction between one type of disc image and another, and started referring to *any* sort of disc image as an "ISO". These days it's not altogether uncommon to see messages about "making an ISO" of an audio CD, which makes no sense at all. Subject: [2-29] Why was 74 minutes chosen as the standard length? (1999/07/18) The general belief is that it was chosen because the CD designers wanted to have a format that could hold Beethoven's ninth symphony. They were trying to figure out what diameter to use, and the length of certain performances settled it. There are several different versions of the story. Some say a Polygram (then part of Philips) artist named Herbert von Karajan wanted his favorite piece to fit on one disc. Another claims the wife of the Sony chairman wanted it to hold her favorite symphony. An interview in the July 1992 issue of _CD-ROM Professional_ reports a Mr. Oga at Sony made the defining request. The "urban legends" web site has some interesting articles for anyone wishing to puruse the matter further. The relationship of Beethoven's ninth to the length is noted "believed true" in the alt.folklore.urban FAQ listing, but no particular variant is endorsed. http://www.urbanlegends.com/misc/cd/cd_length_skeptical.html http://www.urbanlegends.com/misc/cd/cd_length_karajan.html http://www.urbanlegends.com/misc/cd/cd_length_origin.html Searching the net will reveal any number of "very reliable sources" with sundry variations on the theme. ------------------------------------------------------------------------------ [ continued in part 2 of the FAQ ] -- Send mail to fadden@netcom.com (Andy McFadden) CD-Recordable FAQ - http://www.fadden.com/cdrfaq/ (a/k/a www.spies.com/~fadden) Fight Internet Spam - http://spam.abuse.net/spam/ & news.admin.net-abuse.email

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