Subject: [comp.publish.cdrom] CD-Recordable FAQ, Part 1/2
Summary: Frequently Asked Questions about CD recorders, CD-R media, and
. CD premastering.
Date: Sun, 20 Jul 1997 20:46:24 GMT

Archive-name: cdrom/cd-recordable/part1
Posting-Frequency: monthly
Version: 1.9

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
  news:linux.apps.cdwrite

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?

[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 at once?
[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?

[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 calilbration
[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?
[4-19] 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
[5-2] 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?

[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] Jeff Arnold - CD utilities
 [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] Joerg 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
[6-2] 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?
[6-4] I want to write my own CD-R software
 [6-4-1] PoINT - CDarchive SDK
 [6-4-2] 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 this FAQ is encouraged, as are conversions to HTML or
other formats, so long as no content is removed, and additions are clearly
marked.  Distribution on the Microsoft Network by permission only.

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 try to 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.


Subject: [0-3] What's new since last time

Gary Davis (gdavis@loop.com) provided a wealth of information an audio
CD-Rs and DAT recording.  Check out section (5-12).

Roger Kirk (rkirk@videoserver.com) explained the problem with DAE that I
(and many others) noticed on the Yamaha CDR-100/102.  According to Jeff
Arnold, the CDD2600 has this problem too, and the Ricoh 6200S also flakes
out.  [ Lucky me, my favorite compilation CD had this problem. ]  See
section (4-19).

Inserted (0-2).  Added (3-24), (3-25), (4-19), (5-13), (6-1-24), (6-1-25),
and (6-4).  Section (7-8) is now (5-12).


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 lets 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)
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.

See http://www.cd-info.com/CDIC/Bibliography.html for information on
where to get copies of the standards.

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.ecma.ch/ecma-130.HTM for copies of ECMA-130, which 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)).


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.  The disadvantage of
track-at-once is that most audio CD players will play the 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.)

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.

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.
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-E
and CD-R is that CD-E 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 (look for a "multi-read" logo).

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.

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 CDROM, 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.


Subject: [2-14] Should I wait for DVD-R?

No.  Early reports are that the writers are very expensive.  DVD readers
for video are out, and DVD-ROM readers for computers have been announced,
but it will be some time before DVD-R is viable for consumers.


------------------------------------------------------------------------------

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.


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.

Recent versions of Yamaha drives may have trouble extracting 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.  This is rumored
to be a driver problem, though it's not clear what drivers need to be
fixed.

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.


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.

Part of the problem is that the Philips CD specification doesn't require
block-accurate addressing.  When you resume a CD after it's paused, it's
valid to start anywhere in a 75-block range (1 second).  If the CD outpaces
the hard drive while doing audio extraction, the drive will have to stop
and restart reading to avoid dropping a big piece of the audio, and won't
quite start in the right place.  Some drives, like the Plextor 8Plex, use
special hardware that enables them to seek to an exact block.

If you must use track-at-once, make sure you're writing it all in one
session.  Most audio players won't see anything past 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.mainstream.net/~jarnold/cdrom/cdrom.html.

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 make the disc unreadable
on many 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.


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://www.uni-karlsruhe.de/~un60/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 [ the
machine appears to be dead ].

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.
Some FTP sites carry databases full 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
(sales 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?

You need special software, like Adaptec's Photo Theatre or Adaptec CD
Creator 2.  Not to mention 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.  Astarte'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.  Some drivers from Corel will let you choose which session
you see.

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.

Corel includes a session selector with Corel CD Creator v2.x, but it
only works with SCSI CDROM drives.


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).

During playback, 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.

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.
 - 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 currently 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.

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/.

Bear in mind that CD audio is 16-bit stereo at 44KHz, and will chew up
disk space in a hurry.  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").

Possible 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.

Record from the DAT onto your hard drive, and then record the CD from
there.  If you try to do it directly 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 DAT drive with special firmware.  Most SGI workstations can do this.
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.


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.  See section (6-1-9).


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 if you try to
use MPEG source files instead of AVI source files.)

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.

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/), 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 at once?

There is only one known software solution, CD Rep from Prassi Software (see
http://www.prassi.com/).  This combines CD writing software with their SCSI
Rep program to write to multiple SCSI CD-Rs simultaneously.  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.  SCSI Rep apparently
works with other CD-R packages such as Easy-CD Pro 95.

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.


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.)


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 the drive (assuming auto-insert notification is
turned on), 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 it's 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


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 at:

.http://www.reedkotler.com/beta/reedkotler_shell.exe
.http://www.reedkotler.com/beta/reedkotler_help.exe

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 on the Simtel archives called "treediff" that may also
be helpful.


Subject: [3-23] How do I copy Karaoke/CD+G discs?

The following is an excerpt from the document for Jeff Arnold's SNAPSHOT,
which is one of the few software packages (perhaps the only one?) that can
copy CD+G discs:

"To backup KARAOKE CD+G discs, you must have a Yamaha CDR100/102 or
Sony CDW-900E recorder. These are the only recorders that will write
the R-W subcodes required for CD+G discs. You must also have another
CDROM device that can *read* the R-W subcodes as the Yamaha and Sony
can only write these subcodes.

The following CDROM drives can read CD+G discs...

  PLEXTOR 4Plex Plus
  PLEXTOR 8Plex
  PLEXTOR 12Plex
  SONY 76S
  SONY CDU920S"

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.

Check out http://www.cd-info.com/ and http://www.cd-webstore.com/.


------------------------------------------------------------------------------

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.

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.]

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.


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 "dirname<tilde>1"
   you get "dirname<tilde>57".  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).

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 couple of possibilities, one software and one 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)).  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.

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 calilbration

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/avdrive.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.


Subject: [4-18] Why doesn't the copy of an audio CD sound the same?

[ I have yet to see an authoritative answer to this. ]

Most people don't notice any difference between the original and the
duplicate.  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.

Most problems are due to poor digital audio extraction from the source
media.  Some CDROM drives will return slightly different data every time a
audio track is read.  Others, like the Plextor 4Plex, 8Plex, and 12Plex,
will return the same data every time so long as the source media is clean.

The manual for the CDD-2000 reportedly states that the drive uses 4x
oversampling for 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 is more susceptible
to "jitter" on CD-Rs, because the clocking of the bits isn't as precise.  A
quality CD player will compensate for this automatically.

Others have asserted that *any* two CDs, pressed or otherwise, will sound
slightly different.

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.


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.mainstream.net/~jarnold/cdrom/cdrom.html), 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.


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