I am trying to explain basic factors like format instead of what many sources do - assume certain formats according to media type or limits of common software, and gloss over some things that trip people up. I take that approach so that:
- you understand the primary factors, thus don't get confused by detail (as easily :-).
- people know of features that may be in their software but hidden in non-obvious menu locations.
As well I provide information on specific traps, to help people avoid them (or at least understand what went wrong to avoid it next time :-).

Future revisions will be prioritized for my needs, which at this time are firstly data archiving/ backup and secondly limited music recording. (I also use this article as notes for my own benefit.)

This information is for general use, not for steering trucks or flying aircraft where deep understanding, thorough knowledge and rigorous testing is necessary. Use at your own risk, but let me know if you think it is in error.

Regrets, this page needs some editting and checking that I have not had time to do. Meanwhile, any further DVD leads will be added to DVD Information which also contains CD info (but new CD info is in this page).

The latest version of these notes is available at>

My knowledge is primarily of Microsoft DOS/Windows operating systems through XP, not Vista. Readability sections contain some information on other systems, and some of the general disc and format information will be useful for those systems.

I do not cover most mixed formats (such as audio+data) nor most special ones like CD+G (Karaoke) and CD-Bridge. I do cover some common variations like Photo-CD.

(Mostly recent notes needing integration.)
- ISOBuster software claims to be able to create images:
-'s article on ISO 9660 CD format says that it came from the "High Sierra" and ECMA-119 formats.
- That article also advises that Windows 7 may mistake UDF for CFDS.
- I've encountered Windows Explorer refusing to copy a file to a device other than the boot HDD because the filename is almost identical, and other cases where it handles files differently. I have not checked if the file system is different (e.g. FAT32 is often the default on external HDDs whereas NTFS is native to Windows XP).
- Microsoft article 279157 provides information on how the built-in CD recording feature of Windows XP works and advises that it does not support creation of an ISO-9660 image. It seems they are at a minimum talking of creating an image on the hard drive, but they do not detail what the image format is on the CD itself and talk of CD-RW media in that context. (Note the feature does not record in the "fixed-packet" format which on -RW media can be used like a giant floppy disc, only in the standard CD format. Microsoft's feature is a sub-set of one of the popular independent software packages, thus may use its format. (The Adaptec/Roxio one now subsumed into Sonic was not exactly ISO-9660 format, I suspect that's what Microsoft used.)

- The DLA, MyCD/MyCDV, and RecordNow! products produced by Veritas and often bundled with HP drives, sometimes under HP brand, can now be found at (Sonic Solutions). It seems that HP are now bundling a full version of RecordNow! which has more capability while still bragging about ease of use, and that MyCD is now a broader/larger product than RecordNow! (it includes RecordNow! and DLA as well as other software depending in part on distinctions involving the words "suite" and "deluxe" - check "what's new" for a table). From the web site it appears that DLA now supports the more reliable Mt. Rainier format, aka "Easy Write". (Note that the concept of "drive letter access" is not unique to Sonic's product, but like some others they call it DLA.) And Sonic's site has a press release saying they've purchased Roxio's consumer line and that Roxio will morph into Napster. I don't know what this means for tradional Adaptec/Roxio products such as Easy CDC, Toast and DirectCD (which is not named in press releases - it sometimes being lumped with Easy CDC and it being the subject of a patent lawsuit). No, I am not writing this convoluted story on April 1. :-)
- I have been using RecordNow! version 7.x for a year, successfully, to make data CDs and DVDs for archive and backup. It is much better than the earlier version I used with CDs, but lacks some features such as copying a music selection to hard drive to make a compilation off owned audio CDs for use in your vehicle. That feature is available in deluxe versions, if you can figure out their web site. Oddly, version 7 has features to copy an entire CD/DVD, such as saving the CD as an image, but not to copy a single selection - that's backwards.
UPDATE: I upgraded to RecodNow Premier, version 3 I think (numbering system is different than early RecordNow! products). It's a good news-bad news story.
> the user interface is much better, much larger window for one thing.
> it has more capability
> but there are several bugs and awkward aspects, though it is quite useable, but I haven't bothered to reinstall it since I had to reload my computer.
Roxio's software development quality needs improving.

I've added to the information on Mt. Rainier. I need to go through this page and organize the Mt. Rainier information.

Some versions of software run a simulation of recording the disc, before proceeding to write to the disc. (Software usually checks some file parameters for CD suitability, such as name length, before simulating or recording.) You have to be sure that the software actually proceeded to write to the CD. I've had CDs and DVDs, on two drives (one CD only, one CD-DVD, on different computers, using different brands of blank disc), that looked blank though the recording software verified them. (Normally you can clearly see the difference in shade of the recorded area and the remaining blank area, in these cases I had to look very closely to see a difference - I'm concerned some drives may not read the disc, thinking the software may be mis-setting laser power. However, it could be an artifact of the dye or protective layers.) Seems like another reason to buy quality, always use the Verify option in recording discs, and always reboot before recording if you've been doing much work with the computer (thus have risk of software getting fouled up by other software).

- According to Sony's laptop computer website, there is a "DualDisc" with DVD content on one side and CD audio content on the other. Sony advise that the DVD content on the DVD side will play on most Sony DVD players, but the audio side and the audio content on the DVD side may play on only a few because it does not conform to the normal CD audio standard. Furthermore, some CD drives may scratch the DVD side where the label would normally be on an audio CD. Clever but not practical in reality? - many recording failures are caused by dirt on the disc. Be careful storing and handling. (I'm a fan of sleeves that have a soft porus lining, but they can trap grit.)
- Comment: CD-RW media is less useful now because USB memory sticks are readily available and easier to use.
- If printing your own labels on the disc with an inkjet printer, don't overlook water resistance of the ink (lacking in many inks - Microboards technology recommends "water resistant media" from Taiyo Yuden for their duplicating machines, but I do not know how that media addresses the ink problem.
- The Future? CDs remain popular for audio use, and for portability as not everyone in the world has a DVD drive. However, the availability of USB memory sticks will substantially reduce use of -RW media, and the use of solid-state audio players will reduce ue of -R media.
- And another example of software incompatibility, a claim by SanDisk (whose quality is not great either) about Easy CD Creator v3.5, 4.0 & 4.1 interfering with function of their ImageMate CF card reader: "The Easy CD Creator program uses certain APIX.vxd functions that are also incorporated into Windows 98. This alone is not a problem. However, when CD Creator is installed, it renames Microsoft's APIX files. When these files are renamed, compatibility issues arise between CD Creator and other peripherals (such as ImageMate) that use the APIX functions." Renaming Microsoft files sounds like a dumb thing to do. (Patches were provided by Adaptec.)

Files you recorded onto CDs are usually read-only status when copied by Windows versions prior to XP. That can cause problems with software if you've copied data files automatically used by the software. (That happens to all individual files read by the normal directory function - it appears that files inside a zipped file are not changed. I don't remember if fixed-packet recording to CD-RW media changes the status - I'd expect not but that may vary with software brand and vintage.)
Recent versions of some fixed-packet software, such as DirectCD and InCD, can read other popular formats.
TDK sell "Photo Archival" CDs for a high price.

The following factors apply:











11 - Appendices with more details on some factors:







APPENDIX G Draft of notes re backup

APPENDIX H Draft of Keith's Survival Guide

So read on in the order of the above list - or click the link to the section.


Originally CDs were simply molded from a durable master, somewhat like stamping vinyl records but making pits that are covered by a reflective coating and a clear layer of plastic. Then came CD blanks on which data or music could be recorded. The writable CD-Rs have a dye layer that is melted by the laser and a reflective layer, whereas the re-writable CD-RWs have a metal layer that is altered by the laser to vary its reflectivity. For recordable discs the read/record head(s) location is controlled by a servo motor system that optically senses a groove and follows it. (The groove contains information about the blank disc.)

Recordable CDs were developed in two types:
- record once (CD-R)
- rewriteable (CD-RW)

CD-R discs should be used when you want wide readability, you don't need to add or revise files many times, and you don't need to recover space.

CD-RW disks should be used where you want full flexibility of deleting and adding files, are willing to accept substantial limitations on readability, and are willing to pay the higher price of the discs. (Though are more viable for temporary use in write-once recording format.)

Price will vary with pre-formatting (of CD-RW discs), capacity, maximum writing speed, audio use, quantity sold, longevity factors and quality. Typically as advancements are made, including speed, the older discs will be cleared out at lower price - which is attractive to people with slower drives. (The fast discs may provide greater reliability of writing/reading at lower speed, but at the 2X speed of my old external drive I didn't worry. I avoid no-name, and use the premium models for special long-life archives - see LONGEVITY.) Note the two speed levels of CD-RW discs, which are one-way compatible: a disc labelled "High-Speed" cannot be used in a standard slow drive.)

The higher price of "audio" CDs is due to generic royalties for musical performances - a "guilty regardless" principle of government. Worse, the Canadian government has not distributed the royalties it has collected. And the cost actually hurts musicians with low-volume needs. As well, note the fee on basic CD-R discs is paid on millions of CDs used only for data - thus is really a tax.

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Herein I cover the basic file types and arrangements, for readability by the operating system of the computer or audio-video player, not the software application needed to understand the file (such as Microsoft Powerpoint or your obscure geneology software, for example).

Completed discs may contain one of the following:

A - audio in a format matching original music CDs (CD-DA format).

B - sequentially written continuous data, usually on CD-R discs
(This is the original CD format, providing data files or audio tracks. The writing can be done "track at once" or "disc at once".) A variant of this format is "multi- session" in which data is added at a later time.

C - data broken into "variable-length-packets", usually on CD-R discs. Reasonable readability.

D - data broken into "fixed-length packets", necessary for using CD-RW discs as if a large floppy disc on which you you write or delete file by file when you choose.
(Pre-formatting required; limited readability due to UDF format and low reflectivity of RW disc material.)

Refer to Readability for finalyzing actions such as "closing" that affect reading in standard CD drives, including "levels" of ISO. (A key factor is how the disc's table of contents is arranged.)

I'll reiterate the limitations and complexity of the issue of readability encountered with CD-RW disc materials themselves, and the UDF fixed-packet format usually used on them. Their flexibility of writing comes at a price of restricted readability. (The emerging Mt. Rainier format is supposed to be robust and portable - see References for info. However, the emergence of plug-in USB memory has reduced the need for the fixed-packet format.)


Discs for use in audio disc players should be single session CD-R discs, audio format, closed before distributing.

Audio discs can be written one music track at a time, or the whole disc at once. There may be a slight advantage on older players to writing a track at a time. (I speak of audio discs playable in a normal music player - data discs can of course contain music in computer-type files such as MP3 and WAV. Never mind that your computer may appear to show files with .CDA extensions on the audio CD - those are actually tracks.)

Stand-alone audio players usually require a disc made on a blank coded as "audio", which supposedly has royalties paid to somewhere.
Older CD players may have difficulty reading CD-R discs, due to their lower reflectivity. (I wouldn't bother trying CD-RW which will probably be worse.)


Writes in a continous stream of bits, as a single "image". "Mastering" pre-assembles the data to write the entire disk in one pass, then it is closed to ISO9660 level 1 Table of Contents (the most widely readable). You must assemble the complete contents in organized form on your hard drive, or stream the bits from a fast playing CD reader through a fast computer.

Multiple sessions take more space and add complications of reading the table of contents if certain things aren't done. Each session can be "closed" after writing it, but once the disc is "closed" you cannot write any more to it. (Though on an -RW disc some software may be able to reverse the closing action.)
For a multi-session disc you might choose Mode 2 (aka XA) format if you have a choice in the software, as some early drives were optimized too closely to that pioneering format so cannot read a multi-session disc made using Mode 1.). (However, according to Wikipedia it should be Mode 2 Form 2, as Form 1 is not as compatible, and beware it is more tolerant of errors so is not a good choice for data. A Kodak PhotoCD is in XA format.
I recommend avoiding multi-session because of the risk of losing access to earlier sessions if the recording software has a bug (it happened to me using Windows XP and a version of Nero Express 5.5 a bit later than the version that seems to work in Windows 98SE).

Overhead for multi-session may be as much as 22MB plus approximately 13MB per additional session and approximately 10MB headroom to facilitate closing the disc. (Some software estimates the amount - change the setting from multi-session to not and you may see its estimate change.) In contrast, I usually see only 2MB extra space used on a single-session disc, compared to what Properties shows on the hard drive, though occasionally it is more and sometimes only 1MB (I believe that one factor is the number of entries in the root directory, perhaps related to minimum size of things on a CD - on one disc with 54 sub-directories the growth was 5MB, whereas the 1MB was on a disc with only one or two very large zipped files).


Files are broken into variable-length packets, which may be inter-leaved. Useful for adding files incrementally over time then, when finished, converting to ISO configuration for readability in non-writing drives. (That conversion or closing is to ISO9660 level 3.)

May be referred to as "formatted" but is simple, unlike the formatting of fixed-length packets. Packet-writing software will usually default to variable length on CD-R media, as the reuse facilitated by fixed packet is not available on -R media. This format is often used by backup software, which may have its own restore method instead of providing simple readability of the disc. Requires at least 15 MB to finalyze.


The format using fixed-length packets facilitates easy deletion and addition of files as done with floppy and hard disc drives, on a disc that can be erased (a re-writeable disc, usually called a CD-RW disc). Packet writing software will usually default to fixed-length on CD-RW media.

But fixed length takes as much as 150 MB of the disc space for formatting, whereas straight variable-packet takes far less as noted above.

Note that while use of the disc is like writing to a floppy, you cannot format the disc in Windows Explorer XP - separate software is needed, usually supplied by the drive manufacturer. (Apparently the copy-file capability in Windows XP is a version of Roxio Easy CD Creator, using Roxio's version of ISO format, not packet software.)

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An indexing method on the disc is essential. It is what the computer's file recognition system uses to know where each file or track begins, to make a directory list or find a specific file. In most cases a finalyzing action called "closing" is needed to finish the Table Of Contents for widest readability. (Your software may use different terms for that, or do it automatically - look for setting options.)

There are four types of indexing methods affecting broad use.
- Audio discs, straightforward except in mixed audio-data format.
- ISO 9660 level 1 Table of Contents, the original CD format
- ISO 9660 level 3, necessary with variable packet writing (after closing) and/or multi-session.
- The "map" arrangement that is used with fixed packet writing on a CD-RW disc.
(There may be an ISO 9660 level 2 that allows 31-character file names.

The ISO 9660 level 1 format is widely used, readable under several operating systems including DOS, Windows, Unix and Mac (with caveats for other than Windows).
However, recording software may not use that format until you "close" the disc. (The popular Easy CD Creator, for example, uses its own format before the disc is closed, but its support of ISO 9660 is generally better than most software I've heard of.)

An ISO 9660 Level 3 Table of Contents cannot be read by Windows 3.1/3.11, early versions of Windows 95, and Mac o/s prior to System 8, because the o/s or its extension such as MSCDEX cannot deal with files on a CD being in pieces instead of a continuous chunk of data. (Non-Microsoft patches may be available.)

With fixed packet-writing software like Direct CD the disc cannot have a final Table of Contents like normal CDs, except in the uncommon case where software can close it to ISO Level 3. The computer's software translates the disc's detail map into what your computer's normal software, such as Windows Explorer, can deal with using a normal CD drive. That capability is built into the latest operating systems, or you can obtain a file called a "UDF Reader" to install on the computer to read the disc. Refer to an Appendix for details.

And don't panic when you can't display directories (lists of disc contents) correctly. See notes elsewhere in this document and Appendices for traps and tricks, and recognize you can try a different drive or computer (with options of transferring data using another format or media type that may be more readable, a network, or a transfer cable with either Windows' Direct Cable Connection function if both computers have Windows9x or DOS6's INTERLNK/ INTERSVR client-server commands if one or both computers do not.

(I'll briefly mention the native MacIntosh file system, HFS. CDs written to that format cannot be read by other operating systems, but discs can be made in hybrid format by special software. And like PCs, Mac o/s vary in their capability to handle newer things like CDs.)

Note especially the readability limitations of fixed-packet software, including incompatibility of the format produced by various brands of software and vintages of UDF.

3. B. CD-RW

CD-RW discs present an additional reading challenge not related to format. The drive must accomodate the lower reflectivity of the material. This MultiRead capability is only a very few years old, so many computers won't have it. (And forget any ideas of using CD-RWs in audio players - only a few of the latest models may be capable, models from the early 90s may even have trouble with CD-R media.)

The term "erase" may be used too loosely by many people. On -RW media using fixed-packet packet format you can "delete" files. The information will still be on the disc, but hidden, until the space is re-used by adding files - as is the case with a floppy diskette or hard drive. You may be able to re-format the disc, though if errors have occurred I return -RW media to truly blank unformatted state with software that "erases" it. Some software has a "quick erase" capability, which I assume just hides all files and format information to allow reuse of the space they occupy. (I've only used it on unformatted discs that I had used for ISO images.)
(While -R media of course cannot be changed, as it is write-once, on a multi-session unclosed disc you can change files by adding the new versions or hide files by adding directories of the same name as existing ones but not containing the files. In those cases the recording process provides a new index that ignores the old information.)

Refer to the Speed section for information on high-speed CD-RW media.


For widest readability use sequential writing (ISO 9660 level 1), single session, with 8.3 file names containing only capital letters, numbers, or the underscore symbol ("short" file-names in Microsoft lingo), and no more than eight levels of subdirectories.
Some simpler software may default to the Joliette extension to ISO 9660, which includes long file names up to 106 characters and broader language support (note that Macs can only handle file name length of 31 as far as I know, DOS/early-Windows only 8.3 name format.)

Note that disk-at-once sequential writing is needed to make the master for commercial CD replication.

Readability of multi-session discs is normally good, but until the disc is closed you may not be able to read the full contents. (I'd expect software to automatically close each individual session. See Appendix B for more yabuts. In general it is best to avoid multi-session recording if you want the widest usability of discs.)

The flexible format often used with CD-RW discs, fixed-packet format as used by DirectCD et al, has only recently been standardized in the "Mt. Rainier" format. Until then discs created with most brands were not compatible with other brands, though some UDF readers could read some other brands' discs.

You may need to do special things for widest readability on different operating systems. CDs can be written in a "hybrid" format so they seem normal on each operating system - that is commonly done for PC-Mac use - but special writing software may be needed. (Check, http:/, and


CD writing drives can read discs in cases where standard drives cannot, even with multi-read and UDF capabilities. With the accompanying software installed in the computer they can handle more situations and accomodate some errors, such as not having a closed table of contents.

Quality of writing drives and discs can affect readability.

Note that files on CDs will be in read-only format, so when you copy them back into a computer you may have to change the file attribute to writeable (some application software wants write access to the file before you even ask it to change the file).

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Usable capacity of the disc depends on overhead factors described earlier, writing software, and disc manufacturer. Maximum capacity of standard discs is 74 minutes but 80 minute discs are now the norm, giving 650 and 700MB of data respectively. (Earlier discs were 63 minutes/ 550MB but aren't common.) Older drives such as of 1X speed vintage may have difficulty reading 80 minute discs, and some writing software takes the easy approach of using only 74 minutes of capacity regardless of disc capacity. (I see people selling discs with more than 700MB capacity - but can many drives read them?) I now have one high-speed CD-RW of 700MB raw capacity but have not tried it on older drives.

Note that Windows Explorer does not show the overhead from the CD layout. Good writing software will estimate whether or not the data will fit on the CD, but I recommend leaving a few MB spare to be sure. (Files take a bit more space on a CD than a hard drive as minimum block size may be larger - using MyCD/REcordNow and Nero I often see 2MB more space used on an almost-full disc, and in Nero can see the difference in predicted usage between multi-session and standard.)

Some drive-software combinations falsely under-report usable capacity of CD-R discs after CD-RW activity, until the drive is cold-booted. As well, software probably won't recognize that the disc present is only 8 cm size. I doubt software will recognize the extra capacity put in some discs - in one case a drive-software combination wouldn't even consider a Memorex 8cm 210MB CD-R/W as writeable. (The likely cause is that the extra capacity was obtained by smaller spacing between the grooves and the drive cannot cope with that.)

Do not try to push recording beyond 80 minutes - you could damage your expensive recording drive when it tries to follow the groove to where it wasn't built to go. (And short of that your disc may be unreadable in old drives.)

The small ("pocket") CD-Rs of 8 cm diameter usually hold 21 minutes or 185 MB (or 4 hours using MP3 at 128kbps), but 202 and 210MB capacities are available. (See information in References|Media.) Note the Sony "Minidisc" is different technology - it uses a "magneto-optical" method of storing data, in which playback is magnetic but during recording a laser is also used (to heat the media to allow it to be magnetized).

The "business card" cut-off version of the compact CD apparently holds approximately 5 minutes or 50 MB, with some variations in capacity and shape. (See information in References| Media.)

The advantage of compact CDs is of course their small size - they fit into small pockets, wallets and regular size envelopes whereas regular CDs can be somewhat awkward.

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Software is usually of these types:

- sequential write software like Adaptec/Roxio's Easy CD Creator, Ahead Software's Nero, NTI's CD-Maker, and HP/Veritas' My CD or RecordNow.
They write data disks closest to ISO9660 format for wide readability and write conventional audio discs. They should handle multiple sessions.

- packet writing software like Adaptec/Roxio's Direct CD, Ahead Software's InCD, HP/Veritas' DLA, NTI's FileCD, and the new Mt. Rainier standard which use UDF formats for fixed and variable length packets.

- backup software like HP/Veritas Simple Backup, Adaptec/Roxio's TakeTwo, and NTI's Backup NOW!. (See the Backup/Longevity section and the Appendix on backup for factors to consider.)

- A disc erasing utility is useful for salvaging a corrupted CD-RW disc by returning it to blank status. I suggest SuperBlank if you need something more capable than what is built into your recording software. (Some recording software only does "quick erase" which is akin to "deleting" in DOS/Windows, whereas you may need what might be called "unformatting" - return the disc to blank state.

Usually the fixed-packet software installs on your computer in a way that makes it always available in the background to read and write individual files using a CD-RW disk as though it were a huge floppy disc. That might interfere with use of sequential- write software.

Drives (such as LG's sold in mid-2003) and software (such as DirectCD 5.3.1 and recent InCD versions) are now embracing the Mt. Rainier format, which is robust and more portable. However, note you may have to set the software to write in Mt. Rainier format rather than its normal packet format. Be cautionned that implementation of the format was at the leading edge circa 2003, with deficiencies in firmware and software. I've tried InCD's capability which is a bit confusing - it takes time to eject, in part because it puts the standard "EasyWrite Reader" software on the CD with an automatic startup offer to install to help users, and in part because there is a problem adding to the CD after first ejection (error message that it is ull).[move into software section]
The standard allows a quick start to recording, doing its equivalent of formatting on the fly - I am wary of that, which was already available in DirectCD.
The Mt. Rainier standard is referred to as EasyWrite with a tapered coil of wire for its logo.
More information is available at, including a list of capable drives. (To obtain the specification you need to register as an adopter - the license is n/c. Apparently the names "CD-MRW" and "DVD+MRW" are used for the Mt. Rainier format, for CD-RW and DVD+RW media.)

From my experience I make these comments on brands of software:
- HP may supply software with their name, actually made by Veritas.
I find it is not as functional as competing software, unless you pay for upgrade to a higher priced version from Veritas, and its user interface is poor (with minimal Help information). MyCD and its improved version RecordNow! does have some good features, such as doing write speed and read speed tests at the beginning of a job. I recommend against HP/Veritas DLA as it is not mature and not compatible with DirectCD's widely used format. (HP may mix sources for different software functions in the same drive package. That is inviting trouble, but may give you DirectCD rather than HP DLA - that's good.) Thus I would hesitate to purchase an HP drive. (If you need an external drive I suggest a BackPack whose current CD product comes with USB, parallel and PCMICA interfaces and last I checked provided Adaptec/Roxio's full-featured Easy CD product family.

- A 1995 vintage version of RecordNow! from Sonic works reasonably well. An upgrade version was better in most respects but took some steps backward.

- Adaptec/Roxio (now Sonic) had a reputation for bugs in new releases, but they release n/c version updates that fix bugs, have a good web site, and provide capable software.
ALERT: Version 5 of Easy CD Creator has a problem recognizing some drives. Check Roxio's web site for a work-around. And some versions of Toast put information on the CD that might reveal contents of your computer (and the patched version has other bugs).

- DirectCD is a common subject of complaint, though not all complaints are legitimately against Direct CD. (Some are caused by the fragility of the media, some may be caused by quirks in Microsoft's FileManager/Explorer functions in DOS and the original Windows family. In combination with an HP external drive it seems to cause additional anomalies in WinExplorer and sometimes results in problems on a CD-RW disc such as inability to perform further additions or deletions or sometimes even recognize the drive (restarting Windows may clear that problem). I encounter file problems that cannot be cleared. Under Win 98 (v4.10.1998) it seems to hang in certain combinations of directory and file names. (The file can be copied on its own, but not as part of a directory; sometimes the file is listed, sometimes not; sometimes the file is readable but cannot be copied to another CD though it may be copied to a hard drive.). But note that floppy disks weren't reliable either (errors on the disk were common) so we may be seeing the fragility of the media - CD-RW discs have a huge number of individual files which increases probability of having a bad file on the disc. (The foregoing is another reason to buy a quality drive, to ensure correct detail functionality and complete positive phase change in the media - and to migrate to the Mt. Rainier format.)

- RecordNow is now owned by Sonic. Recent versions are much more capable than the circa-2000 version bundled with HP CD-recorders. They seem sensitive to file naming, in one simple case a "moved/could not be found" error message during recording was caused by a file name extension of .mh rather than normal .mht.

- Nero gets praise from many people. (It is for audio and standard data writing. Its companion fixed-packet software InCD is not well known.)
Nero Express has an easy to understand user interface, much better for most people than full Nero though at the cost of defaulting to some parameters. Also of note, it ejects then reloads the disc before verifying, which may help ensure readability in other drives. However, it seems to have the same defect of improperly handling copying of the same left- open disc as just completed (it thinks the new disc should already have information on it, so asks for the disc with that information).
However, the combination a later dual-layer LG drive and the Nero version bundled with it failed to record a dual-layer disc, under Windows 98.
InCD as bundled with an LG drive cannot erase a formatted -RW disc, as is sometimes needed to correct problems or to let non-packet software such as Nero Express use it. (NE has an erase function, but when the disc has been formatted it won't erase it because it sees InCD as already using the drive. NE can erase discs it wrote to. I have not tried temporarily de-activating InCD in startup. In any case it seems a major omission by Ahead Software who make both products and distribute them together.)

- I am advised that Sony's B'sRecordGold has an "o/s compatibility" selection which checks factors like filenames and number of directories for compatibility with different operating systems and advises the user. That sounds useful for advanced users (new users should just stick to simple sets of files and ISO 8.3 filenames).
- I am advised that Sony often bundles yet another incompatible type of fixed-packet writing software with their drives. Some users change to more common software such as DirectCD.

(Purchased versions of the main software for audio and standard data writing usually have fixed-packet software and bonuses on the CD, even though it is labelled with the name of the main software and may install a user interface that appears to be only that name.

Drive manufacturers will usually provide both regular and packet writing software, not necessarily from the same software vendor. Make sure you are getting good software, or a good drive at a price that let's you buy good software separately.)

While software for low-volume CD recording is usually made for Windows and later MacIntosh o/s, there is software for DOS - though it typically supports only SCSI interface not the ATAPI/IDE interface more common in PCs. Try, who also make software for Windows. I understand that software is available for Linux but I know nothing else about that. Linux pioneers are probably happy to tell you.

I don't try to cover DVD herein, but note there are different formats for recording, the technology is immature, even viewing movies may require software (which the movie CD may install automatically), and movies may only be viewable in certain areas of the world due licensing coverage. Good news is that some movie DVDs are multi-language, and some include extra information about the movie.

Windows XP has limited functionality for recording to CD. Primarily it writes an "image" of selected files to the CD, probably in Roxio's "almost-ISO" disc arrangement.
The image file is assembled in a staging area on the hard drive where it is called "StashImapi.bin", then written to the CD on command. Assembly is by drop-n-drag or SendTo the drive letter or by manual copying to the staging area. Some settings are available in a Properties box.
It will nag you if the actual recording to the CD was not done - until you delete the files from the assembly list after worrying about where they would be deleted from (the user interface is not clear).

Windows XP does not provide the packet-writing capability needed to treat a CD-RW disc like a giant floppy and re-use space. Refer to Knowledge Base articles Q294883 and Q279157.

Windows XP can erase a CD-RW. (The menus containing the command are context-sensitive, depending in part on what Windows thinks the state of the disk is, thus confusing.)

Some information is available via RightClick|Properties on the disc or drive icon.


Software is essential to use of your drive but may not be in the operating system, unlike now-standard floppy and hard drives. For CD writing drives, great hardware with poor software does not work - at best you'd have to buy better software separately. So choose it well to ensure it has the features you need and has few defects.

The better software also takes care of a number of details to improve your success rate, and lengthen the life of your CD-RW discs.

Of course it should have minimum number of crawling insects (defects, popularly known as bugs), but beware the industry and technology is not fully mature.


Some software automates too much, not telling you what it did or did not do. Fine, until you have to diagnose. (But this article helps you, right? :-)

The software may automatically do something, such as choose the type of packet writing by the type of disc. Much of the information I provide herein is to help when you have trouble, provide information so you know there may be settings in the software, and to educate you on limitations of drives, discs, formats, and software. This is leading edge technology by home and office standards.

Software may use different terminology (for example, "lock" or "finalyze" instead of "close" on a CD-R, "image" vs "ISO"), or describe a usability result such as "this CD will only be readable in a writing drive". You remember to look in Help to find out what the software can do, don't you? :-) (OK, some software doesn't have complete Help info.)

You may have to scrounge around to find the settings. For example, some options, including closing of an R disc, are under Explorer| Properties (select drive and right-click in the right window pane or in a Properties tab in the writing software), some are found by right clicking the CD icon in the task bar of Windows (DirectCD under Windows 98SE).

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In one-pass sequential writing, the computer and file source must be able to keep up with the recording speed. You don't get a second try on a CD-R disc (it isn't even usable as a coaster, because it has a hole in it :-). Speed is especially a problem if the material is not well assembled on your hard drive or is being read concurrently from another CD-ROM or external drive/memory stick. (Recent better drives do have feautures to reduce the risk.)

I recommend you start at a low writing speed to be conservative, increasing if your experience is solid, but stay low if you want to be extra safe for longevity. See Appendix C for more yabuts and advice.

Note that external drives will be limited by the port speed (about 4x for standard USB, probably similar for parallel, SCSI will vary with vintage).

CD-RW discs were traditionally 4X maximum writing speed. Newer technology goes to 10X or 12X, and even newer to 24X, but cannot be written to in older drives.

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For most people longevity of the disc is not a big issue, provided they are kept out of sun/ultraviolet light and high temperatures. Good knowledge of the longevity of CDs requires time yet to pass, as the technology is only a few years old - accelerated life testing today is good but not deterministic. (Manufacturers have made changes to prevent problems such as sensitivity to sunlight and deterioration of glue. Theoretically.
Kodak claim their Ultima discs include gold for longer life than silver, thus may well be worth the higher price if your data is irreplaceable. Also note that color of the disc is not the prescription many people think it is, as it does not cover all factors and may be altered by other materials in the disc. Among the features claimed by long-life discs are non-flaking label surface and scratch resistant opposite surface.
In addition to Kodak's Ultima Gold, Verbatim offer "Datalife Plus" discs in both CD and DVD capacities, Maxell offer their "Pro" discs which have scratch-resistant layers under the label surface, TDK sell "Photo Archival" CDs for a high price, Fuji offer "CD-R Photo for optimum storage life" (, and Imation offer a "Business Select" line for greater durability.
Some sellers use a term "archival", with wild claims like "300 year storage". Brands may include Adtec, HHB, Maxell, and Verbatim.
And some sellers advertise "master grade recording media", optimized for real-time recording of audio (recording an event direct to CD - desirably with a dual-drive recorder to ensure continuity). Brands may include HHb, Verbatim and Adtec.

Otherwise best results will obtained using high quality CD-R discs intended for long life, good recording drives, quality software, slow speed, and storage conditions that are dark, dry (40% RH is suggested) and near room temperature (definitely not hot). If you need to be very sure, you might copy CDs at five years of age onto new CDs. You might also make more than one backup set using a different brand and recorder for each, and check contents on a different computer (preferably a non-recording drive).

Note that CD-RW discs may be more easily scratched, and can wear out as covered in the following section.

Also note that the reflective layer is just behind the label thus easily damaged. So don't scratch the label, don't try to erase info on it, and use felt markers made for the job (permanent non-alcohol, or Sharpies permanent markers - and don't press hard).

Proprietary formats that limit inter-operability, such as fixed-packet formats other than Mt. Rainier, will face the additional challenge of finding software to read the discs.
And a question for future use is "will you be able to find the necessary application software and run it in order to read the files themselves?".


CD-RW discs are supposed to be good for about 1000 re-writings, but my limited experience is much shorter life. I suggest limiting re-use of backup discs to 100 uses just to be sure the data is there when you need it, especially if using a packet format other than Mt. Rainier which has error-correcting features. Some people just treat them like floppy discs - they wear out too.
Note that some software avoids re-using areas recently deleted from (Windows tends to re-use such areas first). As well, the combination of DirectCD and Windows Explorer over-writes all files of the same name, rather than only those with later date-time, thus causes more wear than necessary.)
You may encounter cases where a fully erased disc fails verification after recording disc-at-once. (You do verify, of course? :-) You can try slow-erasing it again, but should be wary of it.
Manufacturers are developing longer-life CD-RW discs, but the question will be the price difference considering the user's needs and the alternative of write-once discs (CD-R).


For backup of your important data, there are other considerations including:
- whether your method images the drive completely enough to just put the image on a new drive and use the computer quickly, or whether just backing up data is enough for you (in which case if the drive was replaced you reinstall all software then load the data).
- special backup software is a whole subject of its own. (It may not behave the same as your normal writing software, it may use proprietary formats requiring the original software to restore (though it may put executable files on the disc to restore the data), etc. Its main advantage is automation of the list of directories and files you normally back up.)
See Appendix G for more considerations.

And I'll reiterate the importance of quality discs, quality recording, and proper storage.

7. D. TEST IT!

My advice if using CDs for full backup is to test a backup to make sure you can read it in the primary internal CD-ROM drive - not the writing drive, especially if it is external (which may use drivers not in the standard installation of your operating system). For full backup you may need a bootable CD drive. (You can set your computer to first boot from an internal CD drive instead of the hard drive.) Make sure you check out every step in the process that you would have to use in the disaster scenario.

And you keep the backups in a different building than the computer - right? :-) (Preferably in a trusted place out of your earthquake/flood/tornado zone. Some temperate dry place like Prosser WA? ;-)

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I support Intellectual Property Rights. You should not copy other people's property, like pre-recorded music disks.
(I think that copying a few tracks to compile a disc of favorites is fine, provided you continue to own the original CDs and don't use them while using the copy - put them away.)

Note that much of CD technology is proprietary. Arrangements vary (from free use through registered no-charge use to licensing with payment), and affected parties vary (such as a drive maker versus the end user).

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Recordable CDs are still leading edge by home and office standards, thus not as simple and foolproof as established methods of storage.

In general CD-RWs are most useful for:
- Added flexible storage attached to the computer (used like an additional hard drive or huge floppy diskette).
- Frequent backups for the purpose of recovering accidental deletions of a few files.

Otherwise CD-R discs are superior due to their lower price, wider readability, and write protection.

For widest readability take the conservative approach of using:
- CD-R discs of 74 minutes length (650MB)
- regular ISO9660 level 1 form (short file names of simple characters, standard recording not packet method)
- closing disc after writing, to that form
- not too many small files
- slow recording in one session
- quality drives, software & discs.
And keep the discs in a dry, dark, temperate place - secure but not forgotten.

Be prepared to work through finding options in your software, and traps of displaying directories of disc contents.

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Oh, friend, pal, buddy - you can tell the future? What should I invest in to get rich? :-) More seriously, this is new technology and it is evolving. Capabilities such as life and recording speed are improving. There will be a few wrinkles though - such as the inability of older recording drives to write to the newer hi-speed CD-RW discs. And you'll encounter myths and other misinformation. (If you think my article contains some, please let me know. ;-)

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Formatting to fixed length packets puts a "runout track" on the disc, so it does not need closing later (some software can close it to ISO Level 3, but I understand that is not common). As data is written a map is kept of where the pieces of files are. The UDF reader function translates that into a directory that suits your normal software.

To obtain Reader software to install on a computer without a very recent o/s,
- visit the website of your software maker, or
- check for an option in your writing software or its install CD to create the file, or
- check your drive's install CD for filename udfrinst.exe (The Mt. Rainier standard uses the EasyWriter reader.)

One tip for CD-RW discs is to turn off read-ahead caching. Some drives don't fully comply with industry specifications for multi-read, so may have difficulty with areas between packets where the laser recorder ramped up and down.

Refer to for InCD's UDF reader, and compatibility of versions of it and versions of InCD with different UDF readers, and to for similar variations in the version of UDF used by Adaptec/Roxio products and Mac o/s. (Version 3.39 seems to read DirectCD 3xx discs. Information from Ahead is that InCD 1.3 used a UDF format not compatible with InCD 1.61 and later.) Be aware that Veritas' DLA software that HP has been providing is not compatible with DirectCD's format.

Note that a fixed-packet RW disc is not write-protected, until DirectCD messes up and makes it read-only. :-) (Actually, that may be a software hangup not a disk attribute - try restarting Windows.)

Note that errors were common on the old removable rewriteable media, floppy disks. CD-RW discs contain about 400 times more files, which might increase risk of erro - though the media is different and some CD formats include some information facilitating automatic error correction. The "Mount Rainier" standard is intended to make fixed-packet CD format more robust by providing error correction management in the drive. Apparently implemented in both software and the drive, it has a more standardized command set and physical layout. A difference that may affect users is that formatting is done by the drive itself, in the background without o/s involvement, and - at least in InCD's implementation - it must write extra information to the disc before ejecting it. (So the disc can be used sooner but time is lost at end of use. But in the combination of InCD and LG drive that I have there is a defect - the ejected disc is judged full on subsequent attempts to add files. As well, some drives need firmware update to avoid freezing the computer when a Mt. Rainier formatted disc is inserted.) InCD's implementation puts reader software on the disc with an auto-detect routine to offer installation of it - that slows things down but helps recipients use the disc. As well, the drive has 2K of addressable memory to speed drop-n-drag. (It uses a version of UDF format.)

Note each version of UDF, and each brand of fixed-packet software, is not fully compatible with others. (See above re the more standardized Mt. Rainier format now emerging. I am leery of how compatible that will be with existing installations, but have not yet tested reader software from different manufacturers - InCD puts its reader on the data disc.)

If a -RW or fixed-packet disc has file read errors try it in a different drive, especially a recording drive. Also, sometimes copying one file or one directory at a time works when copying several gives errors. Then record the problem files to a freshly erased and formatted -RW, or better yet to a -R in ISO form.

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Newer/better software includes the file list for all sessions in the last session on the disc. Use may be automatic, or by your command such as Import Previous Session, so the list is readable. Otherwise drives may see only the last session, as they are not multi-session capable. (I have seen this from HP/Veritas MyCD which does not have an option to close, and allows multiple added sessions.)

A fine point of multi-session CD-R discs is that you can update files by adding the new version - the software should change contents pointers to ignore the old version. It is still there taking up space, since space cannot be re-used on a CD-R, but should be transparent to your using software. However, with HP/Veritas MyCD I have seen problems with directories - existing material in directories of the same name as added material is not longer visible.

I've seen Windows 98 Explorer show only the amount of the last session under Properties, though the directory listing and file listing were complete, of a disc in CDFS format created by HP/Veritas MyCD/RecordNow being read in both a read-only and a recording drive.

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If your CD is only for Macintosh computers you can use HFS instead of strict ISO.

Some versions of Mac O/S and Unix may have difficulty with the file version number that full ISO compliance adds to the filename (in format ;n).

UDF format may default to Joliette long file names.

Also, putting a large number of small files on a disc may make it unreadable by older operating systems. (Including all MS DOS/ Windows ones that can only read FAT16 directory format, not the newer FAT32 used by Windows 98 and a few versions of Windows 95). Regrets I do not have guidance on the maximum number of files - you could look up the basics of FAT16 vs 32 for clues (may be 244 files).

As well, it is possible to add enough small files to a variable-packet disk that it cannot be closed due to limitations of FAT16, thus will only be readable in a writing drive. (Closing/finalyzing writes a TOC to the disc, and adds a runout track needed by reading drives. The end result is essentially the same as multi-session but the intermediate process may be more convenient than sequential writing.)

Apparently older players, especially in automobiles, may not be able to read CD-R discs as their reflectivity is a bit lower than molded CDs.

I have encountered situations where I had to disable the DirectCD feature of staying in the background for easy use of the CD-RW disc as storage, in order to use other CD writing software. (It may be that ejecting the CD-RW disc will eliminate some problems.)

I've also had cases where running DirectCD itself temporarily disabled reading of the drive (until I re-started the computer). As well, I've seen the drive be unavailable because the disk notification box has not been acknowledged because it is hidden behind something else. (If you don't close the Ejected box and close it after the Inserted box appears one of them will hide behind what you have in view.)

And I've experienced mis-reporting of how much could be written to a CD-R disc, until I cold-booted the HP external drive (the software was using the capacity for fixed-packet formatted discs not the non-packet format being commanded - which has less overhead).

I tried a version of ScanDisc (that supplied as a utility with an HP drive) on an RW disc. It flagged a file I knew was causing problems (offering to delete it), and identified many bad sectors that it could map to an error-free location. However, I did not have time to fix all of them so could not evaluate the end result (apparently the software's "automatically fix" option is not fully automatic or it does not respond to selecting the option, so I had to respond to an error message for each sector). However when I subsequently erased and formatted the disc much less space was available, so apparently it did block the bad sectors or more. (The disc had been used extensively for backup, by Direct CD. I threw it away. (However, I was able to erase one problem disc by using a different computer (different drive and software).) ScanDisc may be worth trying if you have a problem CD-RW and do not have a duplicate or the source data to create a replacement - hopefully you'd get some data off the disc. Otherwise I'd make a duplicate and erase the problem disc.

Apparently hooking up internal CD-ROM drives has traps. Master versus slave, problems sharing and IDE/ATAPI port, and enabling of PIO mode 4 instead of DMA are among issues I've heard of. To have a hard drive and CD on the same IDE port requires setting PIO mode separately for master and slave positions - older systems cannot do that. (Quality is good in BIOS, not just in CDs and CD drives. :-) However, some CD recording software does not cope well with a CD reader and CD recorder on the same port. (While CD-ROM drives use the same type of port as hard drives, handling in the BIOS and software is not identical. (Hard drives use IDE, CD drives use ATAPI add-on to IDE and implementation varies. I've seen a BIOS claim an added CD drive was not ATAPI compliant, but it was.)

People new to CD recording may confuse the term CD-R/W, used for the drive, with CD-RW the media type. I avoid the term CD-R/W, preferring CD Recording Drive (but drives fitting that term were once only capable of recording on CD-R media as CD-RW did not exist).

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You may need to shut down programs running in the background. Get advice on how to do that with your operating system. (Many utility programs are started when your computer boots up into Windows, but aren't in the normal Windows programs Startup menu and don't show up on the bar at the bottom of your screen.)

In general, I suggest a clean boot before recording. That should clear memory and lingering file-in-use flags (which Acrobat and Outlook are especially prone to).

Also, run Defrag on your hard drive to ensure files are actually in one place so they can be read more quickly (normally with deletions and additions some scattering occurs - pieces of files can occupy different areas of the drive).

Writing of large files may encounter automatic re-calibration by the hard drive or the CD writer, which interrupts data transfer - which could ruin your CD-R disc. Better drives wait for you to finish.

Writing many small files will be slower, because each must be opened.

Software varies in its tolerance for long file names, because of the disc format it defaults to. Some web pages think they should cram an essay into a file name, so your software may trip over them.

Pre-mastering of the disc image will reduce speed problems. That assembles everything into one huge image file on your hard drive, which is then just copied to the writing drive in one session. (Pre-mastering writes the TOC at the beginning, as it knows every thing you asked it to put on the disc and assumes that you don't intend to add more later.)

And if you take bulk CDs out of the original package or throw the wrapper away, you may not know their speed - some discs are labelled with speed, many not. Writing a 24x disc at the 48x that recent software defaults to is probably not a good idea. :-)

The conservative approach is to write slowly. Start the automated process then go to lunch. :-)

I recommend that before beginning to record a -R disc you cold boot your computer, including the external recording drive if that is what you have. I've seen problems with recording to an HP external drive if any disc insertion caused DirectCD to pop up its dialogue box. (Use the non-packet software's "Make Another" command to make more than one identical disc, commanding drawer closer through that software, as inserting a fresh blank -R by closing the drawer with the recorder's button may cause DirectCD to get in the way.)


Discs for a stand-alone recording drive must be audio type - that information is pressed into the grooves in the blank.

Note that the inherent nature of a CD-RW disc, including its physical shape, means it cannot be write-protected - unlike floppy discs which have a hole that must be filled in order to write on them. A CD-R disc is write-protected, in effect, by closing the disc.

Apparently it is possible to write packets to a disc that was started with a sequential write session but not closed - so be careful you have the correct disc in the drive.

There is confusion over allowable combinations of format and disc type. I think any format can be used on any disc type, in theory. However, only some combinations are really useful, so some software limits you to those. A simple approach is:

- You are paying the price of using CD-RW to get its flexible re-write capability thus only fixed-packet is of great value.
- With CD-R discs you only get limited second chances (and only by adding session(s), so fixed-packet is of no value. (Hmm - you'd have a formatted disc with no files on it. Really useful!)

For those into a lower level of details, there are bytes and blocks of binary data on an audio CD, but no files as such - no header. Your o/s directory function lists the tracks like files - on my computer just Track01.cda, Track02.cda....

A copy is not a copy? Software that appears to copy a CD may not actually make a literal copy, 100.0%. Subtle details may be changed or omitted. To figure that out, you probably need to get into understanding "images" and what your software actually does (typically it does not write true ISO9660 but its own unique adaptation, sometimes offering a closer configuration in an obscure place in its menus).
Also note the difference between copying files and copying a CD. Files can be copied onto the hard drive then written to a CD. Using packet software files can be copied to a CD-RW individually, from any source. When copying a typical CD-RW it is best to copy files not the disk because the source CD-RW may be fragmented.

There may be limits on the number of files on a CD (perhaps depending on use or length of long filenames), limits on length of filenames (110 characters), and limits on number of sub-directory levels. They may vary with the operating system and software used. (Apparently Nero can write "relaxed ISO" with more than 8 directorylevels and path information longer than 255 characters, but I do not know what software can read that.) If you want to write strict ISO I suggest you change file names yourself, as writing software will truncate to names that may be less meaningful (I've seen Nero truncate, including using xxxxn.zzz where n was 1, 2 and 3 where the first part of the original filenames was the same).

Locked files: note that files written to CD often have the attribute ReadOnly when they are copied back onto the hard drive, even when from a CD-RW disc. To unlock them, open WinExplorer and:
- highlight the folder(s) or file(s)
- right click for menu then command Properties
- uncheck Read-Only (if grayed out using ALT-R works)
- repeat for all folders and files at lower levels (action on a folder name does not change the files in it)
Note that the cursor must be in the highlighted area for the Properties command to correctly display and take action on the attributes.

If you are into spending time trying to use older drives, I suggest you will find greater usability if the drive complies with the MMC command set. (I do not have leads to the MMC definition.)

When using packet software such as DirectCD you may find that the disc can be read but not written to. Check that DirectCD is running (it may have been disabled during troubleshooting or because the computer reverted to an earlier registry due problems).

CDs play from the inside out toward the periphery.

"CD Extra" is music CD with artist's information. A game CD is probably "Mixed Mode".

NTI's CD-Maker Pro includes FileCD2.0 and an erase utility, can make Mixed Mode and CD Extra.

Some software has a volume setting for recording audio discs, buried down in menus.

Labelling can be a bother. It must be on straight to minimize imbalance in fast drives. One label company produces removable labels that may be handy for CD-RW discs. Ink jet printers with CD-printing featurs are now available.

And what about defects in writing software and recording drives? For example, LG's web site offers a firmware flash upupgrade with this cryptic explanation: "Improvement Point: enhanced recording of some CD-R media.". Now I'm worried, about what I don't know about. :-)

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Audio players may have difficulty handling home-recorded CDs. For example, one 1994 Chrysler-branded Alpine vehicle player could not recognize a standard 80-minute CD-R (made with less than 74 minutes of music on it) - it did play a CD-R made on an audio blank of 74 min minutes length but with noticeable delay on power-up and longer delay between songs.


I've seen several anomalies in reporting contents of a disc, especially a CD-RW:
- Windows may not accurately report space available on a CD.
- Some recording software incorrectly shows the space available on a blank 8cm CD as the 700MB that a full size CD would have (Nero Express for example).
- Space remaining may show as zero in some places, especially with -R discs or read-only drives. (In Windows 98, Control Panel|Properties will show the actual amount used, which you can compare with the disc capacity, considering the different overheads as described earlier. In DirectCD using its Properties button/tab may also show unused space. (That function may also allow adding or changing the disc label.)
- Windows, with some CD writing software, may not refresh the directory or disc volume label in Explorer when you change CDs. Try F5 or shutting down and restarting Explorer or Windows as necessary. (Explorer may display the label of a previous CD when the current CD has no label.)
- I've seen a CD-RW reported as having a single file whose name had no apparent relationship to the contents, when attempting to read it with Win31's file Manager in a drive that probably could not read an RW disc's low reflectivity.
- I've seen files not shown as on the disc, by Windows Explorer original edition, yet the Copy command asks if the user wants to over-write the file. (Using DirectCD3.xx. F5 did not show the file.)
- And there are other traps with PCs that may look as though there is a problem with a specific disc. For example, PKZIP version 2.50 for Windows will advise "file not found" then "incorrect password" if you try to open an individual file from within a password-protected zipped archive on a CD, but work if you copy the archive to the hard drive - even without chaning the read-only status.

Adaptec/Roxio deserve an F grade for a feature in Toast, the CD-recording software popular on Macs. According to the VMUG newsletter of March 2002, referencing MacFixit and VersionTracker (web sites, I think) Toast puts desktop and related computer contents info on the CD thus can reveal what is on your computer. Version 5.1.2 limits and explains that, but apparently has bugs that cause problems running under o/s X).

Installing the software for packet-writing can inconvenience you:
- It seems as though the TSR to use the CD-RW as a huge floppy interferes with some other functions of the drive.
- A recording drive must have autorun on (notify on insert) to use the TSR for packet writing. That is not convenient for database CDs that also contain an install program, and you'll be putting wear on a more costly drive. (Though prices have come down so much wear may only be a concern with the new DVD recording drives whose price is higher though decreasing.)

To copy an audio disc, the player must support Digital Audio Extraction - otherwise you'll get some noise on the copy. (Some recent CDs use techniques to prevent DAE, for copy protection - apparently they sound bad in honest listening if the computer's player has a fully digital listening path.)

Keep in mind that CD recording drives are slow compared to hard drives. Treat them like a floppy drive - give them a bit of time to finish doing whatever they need to after deleting or writing, and to be recognized after changing the disc. (For example, DirectCD has two periods of drive activity after inserting a CD. Trying to read the CD before the second period starts tends to foul DirectCD up. Also, closing/finalyzing a variable-packet CD may take a few minutes on a slow drive.)

If you damage the covering on the printed face of the CD, it may not work as the light may just pass through. (Caution if buying CDs in bulk at low price: some have no printed side, because they are meant for volume production equipment that applies the covering to label the CD. (Some might consider that an excuse to buy the low priced inkjet printers now available with a CD-holder and flat feed to print on CDs. :-)

A -RW disc may not be erasable due to corruption of the TOC. Exposure to strong light, especially UV, may work.

You may have times when the CD drive does not eject the CD using the button. I suggest trying these in order: closing the software that was using the drive, looking for an eject command in software, and turning power off then using a large paper clip in the hole intended for releasing the tray (first read the instructions for your model). DirectCD usually installs with an icon in the Windows tray (bottom of screen) - right-clicking on it should show a menu that includes Eject.

Before using a cracked disc, you might find an old slow speed drive. Recent drives turn at very high speed - there is some risk the disc could come apart thus not be readable, and damage the drive.

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Hewlett-Packard's web site has good guides in its Product Support database. (Search on general keywords in addition to your drive model number.) Other drive manufacturers may have information on their web sites.

Compuserve forums have information and advice. Outsiders may be able to see some of the forum information, at is a "Primer" on the subject, with depth. (Opens to a Table of Contents - much detail available by selecting subject. He provides the technical reasons behind many of the statements in this article.)

The Puget Sound Computer User newspaper recommended CD Recordable Solutions by Martin C. Brown as worthwhile. They advised it attempts to be comprehensive but is somewhat variable in its depth on each subject. They also mentionned Peachpit's book Little Audio CD Book as a peppier but non inclusive book.

FORMAT for highly technical information on UDF, Multi-Read, and Multi-Play requirements. are suing some producers of packet recording software for violation of a patent that facilitates simple recording by writing a small header on a blank disc then a revised directory at the end of each session.

Packet recording facilitates recording by methods already in a typical o/s, as little as a file at a time, and minimizes risk of buffer under-run. My modest understanding is that variable-length packets best suit sequential recording without ability to re-use space, such as must be the case with CD-R media. Fixed-packets can be used for that, perhaps preferred for wider readability, and are necessary for re-use of space as often desired on CD-RW media. (In that case the disc must be organized before hand into spaces of identical size - i.e. fixed-length. That is called "formatting", as well known for floppy discs and hard drives. has FAQs and tips on readability for users - dig around, follow the links from one FAQ to others to find it all. has information on CD images especially for Mac operating systems, and software to create a hybrid CD on a PC. It provides a very readable explanation of how a hybrid PC-Mac CD is possible. As well, it explains ISO image formats used by various writing software and explains how to create a true ISO image.

See also for FormISO which can build an ISO9660 image under DOS.

See for UDF readers for the Mac, including a note that Mac o/s 8.1 handles only an earlier version of UDF whereas DirectCD uses a later version. Also for information on a freeware extension to read Joliet filenames.

Ricoh may have advice on their web site - I've read a good article called "Multi- Session CD Recording: the Rest of the Story" from Ricoh.

CD-i (interactive) information is available at: has information on the Mt. Rainier format (CD-MRW and DVD+MRW).
Software Architects Inc. has writing, reading, and repair software for UDF format discs including Mt. Rainier. (

Apparently Matsushita and Microsoft have a recording capability for graphics and audio that can be added to Windows XP (refer to Knowledge Base article 831240).


The Support section of has some special utilities for people deep into things. (Dantz sell backup software.) The Solutions section has tips and advice for backing up your computer or network. has brief information on recording and on firmware upgrades for some CD writing drives. (Goldenhawk make sequential CD recording software that includes capability of using several drives, automated drives, and SCSI drives under DOS.)

This site has info on professional recording of music:

This company sells software for recovering problem CDs and examining CDs:
Here is an unchecked link to software for examining content of CDs, possibly to help recover files: has information on recording speed. has good info.

Software called IsoBuster may be able to recover files not visible in the TOC written by the last session of a multi-session disc. IOW, it can look into all sessions.


Disc makers like Imation and Maxell may have basic information on their web sites, if you can put up with the slow loading of Maxell's site.

(Here is a modest-volume CD copying station.)

(Maxell are rearranging their information pages, but try this one:
Kodak provide simple information to get you started:
and more detailed answers in their publication library (search it for CD-ROM):

The web site of I.D.Rom vendor Rompus Interactive provides some information on the business card sized CDs.
Those CDs come in at least two versions, none of them actual business card size:
- one is approximately 6 cm high between straight edges, the other two edges follow the 8 cm round shape. Sometimes called e-cards or even "hockey rink shape" in Canada (someone hasn't been close to a regulation shape hockey rink, which has rounded corners joining straight ends :-). Memorex is one brand.
- the other is approximately 6 cm high, rectangular, and appears to be about 8.5cm wide, perhaps a bit more. Imation and CompUSA make some.
(The 6 cm dimension may be as much as 6.3 cm on some brands, and labels may be made to the larger dimension thus awkward to use on the smaller cards.)
Rated capacity of the two card shapes is approximately the same - I've seen both 48 and 50 MB, perhaps for 6 and 6.3 cm. (CDs use a single track beginning near the center, so capacity of these forms is limited by the height.)
Supposedly they fit tray drives, though I don't know how the rectangular one fits well enough to center properly (some drives - popular in laptop computers - hold the CD by its center hole thus should hold these well). According to one producer of children's software the round ones do not work in the slot drives that Apple used on some Macs - I presume the card style shouldn't even be tried (I envision those corners whacking something inside). In my opinion they are cute, but as they are not actually the size of business cards and as the small round discs have over three times the capacity the "business card" size is only useful for its appearance - it gets noticed.

Round 8cm discs:
(Several years ago music was issued on them, akin to a "single vs LP" record difference.) Prices have come down, selection is greater, and both -R and -RW blanks are available. I understand they are widely readable, though limited reports suggest the -RW version is even more troublesome than the full size -RW discs. My drives hold them well (one in a depression in the tray of a standard drive, the other by the center hole method of laptop drives). Check tax rate in Canada, in case they are considered equivalent to mini-discs. Apparently they are used in some digital cameras and MP3 music players, so prices have come down due to greater volume.
They are 2/3 the diameter of regular discs, but much easier to tuck away (slightly smaller than 3.5 inch diskettes, they fit in pockets, wallets and regular envelopes).
Capacity is only 1/4 of a regular CD, because surface area varies as the square of diameter so gross area is less than half, and the unused dimension at edge and center is the same so net usable area is small.
And one vendor refers to them as "3 inch" (beats me why a vendor in the land of much metric, Canada, would not use the 8cm term - which is actually 3.15 inches).
Plastic cases, clear plastic sleeves, and paper sleeves are avaiable from and, as well as display mailing envelopes, but not the nice sleeves with grit trapping material inside. If anyone has individual diskette envelopes in a dusty corner, they should work - the fit will be loose so you need a closure flap, thus those binder pages with open pockets won't work well. (The CDs are much thinner than 3.5" diskettes.) Some people may find the flat diskette boxes at Staples useful for holding 6 of the 8cm CD cases - or perhaps other diskette boxes.
Hopefully the use for MP3 players and cameras will help ensure they are supported for years. (Has anyone seen 2 inch floppy diskettes recently? I saw Fuji LT-1 diskettes in a surplus store. :-) (Hey, that's better than the 2.88MB version of the 3.5" diskette - I've only seen one, which came with my unwise purchase of a drive and special controller card - 2.88MB isn't even standard in high-end computers that I've noticed.)
There is a small round format by Sony called mini-disc, but it is a sophisticated magnetic technology using a laser to heat the media to magnetizable temperature.

The file 1095.pdf on Phillips' intellectual property web site has gory details of what is required for high-speed -RW, including why old drives will not write to the >4X media.)


- labels must be centered accurately to avoid vibration as the drive spins at high speed
- use only felt marker pens for writing on the disc's label side (non-alcohol, permanent ink)
- if using ink stamps you'll need the special expensive ink that gives stronger coverage
- inkjet printers are now available with holders for CDs, at home budget prices. (You can purchase CDs with a plain white surface to print on.)


(Not complete nor up to date.)

DVDs are most popular with video users, secondly for data sets that would require several CDs. (For example, large phone number listings, encyclopedias, and map sets are readily available on DVD to provide the convenience of not having to switch CDs. Laptop users might especially appreciate those as one disc can be kept in the drive for reference (Microsoft Encarta Deluxe, for example - a five CD set including encyclopedia and dictionary).

A guide to recording DVDs and related formats, including assembly/recording software, was published in a recent issue of Performance PC magazine,

From that I list media types:
- DVD-R (widely compatible)
- DVD+R (perhaps more widely compatible than -R)
- DVD-RW (rewriteable, medium compatibility)
- DVD+RW (rewriteable, medium compatibility
- DVD-RAM (not very compatible) DVD capacities include: - DVD-5 (4.7GB) - DVD-9 (dual-layer single-side) - DVD-10 (9.4GB, dual side single layer) - DVD-18 (dual-side dual-layer) However for most people anything but the 4.7GB basic DVD is academic due cost.
(VCD and SuperVCD are formats placing video on standard CDs, "miniDVD" puts DVD-quality video and audio on a CD.)
And there are other complications, such as 16:9 versus 4:3 display aspect ratio, the various file formats such as MPEG and QuickTime, and the NTSC versus PAL TV display incompatibility.

Some leads to video assembly/editing software:
- Ulead (now Roxio?)DVD Workshop
- Adobe Premier or Encore
- Sonic Foundry (including Vegas and the more advanced DVD Architect)
- Pinnacle Studio
- Roxio's ECDC4.0 may have limited capability to create a video CD from movie files, recent versions of Roxio and Nero software have much capability.
- DVD-Lab is powerful at an attractive price, with simple interface, from Mediachance.
- Apple's DVD Studio 2.0, for the Mac of course
Various levels of automation may or may not be provided, to reduce the number of steps you need to take to do the job.

A brief overview of DVD format options and recorders is at: (Seattle Times of June 11, 2002). As well, Verbatim may have simple guides. Some recorders can handle more than one format. And PC Magazine of January 2003 had a comprehensive article - may be available at Smart Computing magazine of January 2003 has an article on recording to CDs and DVDs. DVD+RW information is available at: They indicate it is more interoperable with CD formats than other common writeable DVD formats such as DVD-R and DVD-RAM. Video CD may be covered at

DVDs should contain a UDF file structure and may contain an ISO file structure.

Older DVD players may not play VCD format. (Older or cheaper DVD players handle fewer of the DVD formats.)

It appears that the X in speed rating of DVD recording drives is 4 times that of what is used for CDs, but I have not had time to verify that.


(Of CD specification books not media.)

Red: digital audio and CD Extra
Yellow: Data CD (mode 1)
Green: CD-ROM XA & CD-I (mode 2, form 1 and form 2)
Orange: TBA (Not another acronym, but To Be Advised :-)

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Appendix G - Draft of notes re backup

Features to consider:
1. Replace files of earlier date, leave others (faster than over-writing all as WinExplorer/DirectCD does on CD-RW). Usually called "incremental", you have to keep the previous backups going back in time through the last full backup.
2. Flag files no longer in current folders (i.e. may have been deleted).
3. What media? (e.g. floppy vs CD vs DVD vs tape, single vs "span-disc set")
4. Restore method and readability. (E.G. simple copying vs automated restore routine. Some backup software uses its own executable included on the backup media. Some backup software creates an image from which one may or may not be able to restore individual files - you want top be able to restore individual files because restoring the entire drive would over-write any changes in registry/setup since the backup.) Some software creates a disc that is not readable in a read-only drive, so you have to have a recording drive (and the drivers for it, really user-friendly!).
5. Backup of files only or entire hard disk.
6. What support is needed to restore? (E.G. are special CD drivers needed to restore that may not be on a new or reformatted hard drive? Often the software that makes Recovery or Disk Image CDs provides a floppy that boots into DOS, with complications, or requires the computer be set up to have CD drivers available in DOS or Safe Mode (such as a boot floppy (which Windows 98SE can make with generic drivers) or addition of real mode device drivers in the AUTOEXEC.EXE and CONFIG.SYS files (which are still there underneath Windows 9x). (Those drivers may not be provided by the installation of the recording software which is Windows-focussed.) Windows XP has its own scheme of startup menu options, custom boot floppy, or generic boot floppy set (see and search on "floppy boot" [sic]). And note the BIOS setup may need to be changed to boot first from the CD-ROM drive rather than the hard drive.
7. How does the software assemble the backup? (It may require it to be stored on the hard drive before transfer to removable media - thus requiring much spare space on the drive.)

PC Magazine of January 2003 has a recommended features checklist for backup.
The user manual for Retrospect Express may have guidance beyond just instructions for using RE itself.


- the term "image" in the context of discs means a faithful copy of the entire contents and structure, usually as what looks like a single file to typical o/s directory functions
- in contrast, copying the contents of a disc file-by-file may not reproduce the structure (an extreme example being copying files from a floppy disk to a CD).
- it may contain individual files within it but in a form not readable by the normal directory functions of a computer. A rough parallel is a zipped file - one must either unzip it into its constituent files or have extra software that can look inside the zipped file. (When a CD-ROM drive is installed under DOS thus Windows "family 1" the Microsoft program MSCDEX is installed to provide that ability for a conventional CD-ROM disc. (For a fixed-packet CD-ROM disk a "UDF reader" program of the right version and brand is needed.)
- The software that assembled the image file will provide some type of list within the file - the Table of Contents in ISO 9660 CD format, for example. The list and referencing within the file may be called a "file system". It may or may not allow the file to be spread across multiple CDs (later versions of PKZip do, MSCDEX does not).
- the term is used in mastering a CD by assembling the contents on the computer's hard drive then writing it to a CD in the common ISO9660 format. The result on the CD is sometimes called an "ISO image", and on the hard drive it is usually in a modified-ISO format proprietary to the CD recording software that you use to assemble it. (Roxio's Easy CD Creator is notably more different from ISO than most recording software.)
- by now you may observe that use of the term "image" is somewhat variable. For most people the precise definition may be less important than knowing the file is not the normal kind that regular computers can handle - "what extra capability do I need to deal with it?", and what it does for you compared to normal files.
- provides much information on "disk images".
- note that a disc need not use the normal structure we expect in standard DOS and Windows, and may not have the same capacity. The key is that it can be read for its particular purpose - which may be by an installation routine on the disk itself.
- also note that an image of the complete contents of a hard drive is not necessarily everything on the hard drive, as the hard drive may use some space for its own calibration data (as well, there may be a small area that is only accessed by some o/s functions or by simple routines that will have to be installed again).

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Appendix H - Draft of Keith's Survival Guide

1. This is leading edge stuff - many of you will have problems, many of you will get confused. But it is not "bleeding edge", so press on and learn.

2. While CDs all look the same to the novice, they are not. See point 5 regarding construction and writing format.

3. While software makes the CDs look like floppy and hard disks, they are not - in part because they are not fully integrated with older operating systems, in part because their file system is different. You will see things that confuse you, including things that are plainly misleading, and encounter differences in how the types of media are handled. You are accustomed to using hard drives & floppy disks - and the software for them works well though not perfectly. CDs are not at that stage of understanding, user interface, and maturity of software function.

4. Treat written CDs like floppy disks were in the days when sizes and even formats differed, thus readability depended on:
- drive capability and vintage of operating system (e.g. PC DOS3 used different format than DOS2)
- condition/ quality of the diskette (errors were common on those rewriteable disks).
(If your mind, your memory, or your use of computers is not that old, I expect you get the general picture anyway. :-)

5. Learn the essential differences between manufactured CD, CD-R, and CD-RW discs, and between normal writing software and that needed to use CD-RW discs as giant floppies. (I suggest starting by using the simple guidelines in my article, then progressing to more detail and more variations as you get the basics locked into your memory for good recall.

6. Use simple ISO disc at once recording on CD-R discs for widest compatibility and best reliability.
Use CD-RW and fixed-packet software only for temporary non-critical flexible storage on the same computer or computers you know are fully compatible in hardware and software. (If you really want to use fixed-packet software, try to get a drive and software supporting the Mt. Rainier format and provide users with compatible UDF Reader software.)

7. If you are doing a particular task often, make a checklist specific to what you are doing, to help ensure you do all necessary steps and avoid traps.

8. When a problem occurs, don't panic - re-read my article to see if there is a workaround or recovery method or simple trap you fell into.

9. Patience.

10. Be extra careful with CDs that contain material no longer on your hard drive. That is even more important than for regular data backups - they are your data, the source of their content no longer exists. See point 7 to help ensure a good result.

And the short list of basic factors and advice:
- A recording CD drive requires recording software, except with the newest o/s which include some software (for "drive letter access (fixed-packet) format that software hides in the background once you've installed it).
- CD-RW media can be reused many times, CD-R media is write-once (but can be done in separate sessions). - Audio (music) CDs for general use are a unique format. (And some software and recorders require blanks encoded as special for audio recording.)
- Use a CD-RW disc as though it is a giant floppy disk. It requires fixed-packet writing software. There are several different formats, each requiring its own Reader.
The discs must first be formatted, and can be wiped with "erasing" software then reformatted. (That software may be separate from the software used to record normal data and audio CDs.)
The new Mt. Rainier format is more reliable and portable than proprietary formats.
- Data CDs are normally written in one of the ISO9660 levels. They need to be "closed"/ "finalyzed" after recording for widest readability.
- Mac and Unix o/s are different from PC o/s, with limitations on interchange especially if you don't keep it simple or use hybrid disc formats.
- Record slowly, especially if your drive is external or your PC slow or you are using cheap discs. (Reboot before recording, and if it is really slow learn how to maximize computer speed without changing the hardware.)
- A recording drive may be able to read CDs that a read-only drive cannot. Different drives may read better or worse if you did not follow the next point or if a drive or disc is failing.)
- Quality is a good thing, in drives, media and software. CD-recording life is too complex already without adding flakiness to the puzzle.
- Conservative is good for widest use or greatest dependability. Keep it simple, do it slow, and be thorough.
- Intellectual Property is moral, don't steal it.

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Copyright Keith Sketchley page version 2013.06.11

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