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Cygwin

Cygwin is a free and open-source Unix-like environment and command-line interface for Microsoft Windows. The project also provides a software repository containing many open-source packages. Cygwin allows source code for Unix-like operating systems to be compiled and run on Windows. Cygwin provides native integration of Windows-based applications.

The terminal emulator Mintty is the default command-line interface provided to interact with the environment. The Cygwin installation directory layout mimics the root file system of Unix-like systems, with directories such as /bin, /home, /etc, /usr, and /var.

Cygwin is released under the GNU Lesser General Public License version 3. It was originally developed by Cygnus Solutions, which was later acquired by Red Hat (now part of IBM), to port the Linux toolchain to Win32, including the GNU Compiler Suite. Rather than rewrite the tools to use the Win32 runtime environment, Cygwin implemented a POSIX-compatible environment in the form of a DLL.

The brand motto is "Get that Linux feeling – on Windows".

History
Cygwin began in 1995 as a project of Steve Chamberlain, a Cygnus engineer who observed that Windows NT and 95 used COFF as their object file format, and that GNU already included support for x86 and COFF, and the C library newlib. He thought that it would be possible to retarget GCC and produce a cross compiler generating executables that could run on Windows. A prototype was later developed. Chamberlain bootstrapped the compiler on a Windows system, to emulate Unix to let the GNU configure shell script run.

Initially, Cygwin was called gnuwin32. When Microsoft registered the trademark Win32, the "32" was dropped to simply become Cygwin.

In 1999, Cygnus offered Cygwin 1.0 as a commercial product. Subsequent versions have not been released, instead relying on continued open source releases.

Geoffrey Noer was the project lead from 1996 to 1999. Christopher Faylor was lead from 1999 to 2004; he left Red Hat and became co-lead with Corinna Vinschen. Corinna Vinschen has been the project lead from mid-2014 to date (as of March 30, 2023).

From June 23, 2016, the Cygwin library version 2.5.2 was licensed under the GNU Lesser General Public License (LGPL) version 3.

Description
Cygwin is provided in two versions: the full 64-bit version and a stripped-down 32-bit version, whose final version was released in 2022. Cygwin consists of a library that implements the POSIX system call API in terms of Windows system calls to enable the running of a large number of application programs equivalent to those on Unix systems, and a GNU development toolchain (including GCC and GDB). Programmers have ported the X Window System, K Desktop Environment 3, GNOME, Apache, and TeX. Cygwin permits installing inetd, syslogd, sshd, Apache, and other daemons as standard Windows services. Cygwin programs have full access to the Windows API and other Windows libraries.

Cygwin programs are installed by running Cygwin's "setup" program, which downloads them from repositories on the Internet.

The Cygwin API library is licensed under the GNU Lesser General Public License version 3 (or later), with an exception to allow linking to any free and open-source software whose license conforms to the Open Source Definition.

Cygwin consists of two parts: Cygwin supports POSIX symbolic links, representing them as plain-text files with the system attribute set. Cygwin 1.5 represented them as Windows Explorer shortcuts, but this was changed for reasons of performance and POSIX correctness. Cygwin also recognises NTFS junction points and symbolic links and treats them as POSIX symbolic links, but it does not create them. The POSIX API for handling access control lists (ACLs) is supported.
 * 1) A dynamic-link library in the form of a C standard library that acts as a compatibility layer for the POSIX API and
 * 2) A collection of software tools and applications that provide a Unix-like look and feel.

Technical details
A Cygwin-specific version of the Unix  command allows mounting Windows paths as "filesystems" in the Unix file space. Initial mount points can be configured in, which has a format very similar to Unix systems, except that Windows paths appear in place of devices. Filesystems can be mounted in binary mode (by default), or in text mode, which enables automatic conversion between LF and CRLF endings (which only affects programs that open files without explicitly specifying text or binary mode).

Cygwin 1.7 introduced comprehensive support for POSIX locales, and the UTF-8 Unicode encoding became the default.

The fork system call for duplicating a process is fully implemented, but the copy-on-write optimization strategy could not be used.

The Cygwin DLL contains a console driver that emulates a Unix-style terminal within the Windows console. Cygwin's default user interface is the bash shell running in the Cygwin console. The DLL also implements pseudo terminal (pty) devices. Cygwin ships with a number of terminal emulators that are based on them, including mintty, rxvt/urxvt, and xterm. The version of GCC that comes with Cygwin has various extensions for creating Windows DLLs, such as specifying whether a program is a windowing or console-mode program. Support for compiling programs that do not require the POSIX compatibility layer provided by the Cygwin DLL used to be included in the default GCC, but, it is provided by cross-compilers contributed by the MinGW-w64 project.

Software packages
Cygwin's base package selection is about 100 MB, containing the bash (interactive user) and dash (installation) shells and the core file and text manipulation utilities. Additional packages are available as optional installs from within the Cygwin "setup" program and package manager ("setup-x86_64.exe" – 64 bit). The Cygwin Ports project provided additional packages that were not available in the Cygwin distribution itself. Examples included GNOME, K Desktop Environment 3, MySQL database, and the PHP scripting language. Most ports have been adopted by volunteer maintainers as Cygwin packages, and Cygwin Ports are no longer maintained. Cygwin ships with GTK+ and Qt.

The Cygwin/X project allows graphical Unix programs to display their user interfaces on the Windows desktop for both local and remote programs.

title: Cygwin


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Talk:Canadian English

Citation problems?
The article currently contains warning templates saying "this article has an unclear citation style" and "this article needs additional citations for verification". It's not clear to me that these are still issues with the article. What do others think? — Rich wales (no relation to Jimbo) 23:06, 9 April 2021 (UTC)

 * I looked today, there were some odd means of citation in the middle of the article, such as MLA-style parenthesis citations for source citations, such as ([80]), etc. I tried to clean these up as it was visual clutter, although, it just seemed to be that section and otherwise I believe the article is fine in this regard. Moonsoftoday (talk) 12:54, 26 June 2023 (UTC)

Reference 80
Reference 80 (gov.ns.ca) is broken HTTP Error 404.0 - Not Found. Unable to find appropriate and working link. — Preceding unsigned comment added by NerillDP (talk • contribs) 22:15, 24 March 2022 (UTC)

Phonetic Detail
A full explanation of what sounds are used for what words need to be included, whether or not we use IPA or not. Also an explanation of how regional Canadian English varieties have shifted from, or have always differed from, the Canadian/American standard should be included and maybe a diagram or two with some arrows comparing corresponding vowel sounds would be good. Compare this article with https://en.wikipedia.org/wiki/Inland_Northern_American_English for example. A good start would be explaining the fact that some Canadians say ‘oot’ for ‘out’, ‘treeler pairk’ for ‘trailer park’, ‘cur’ for ‘car’, ‘oover’ for ‘over’ and occasionally even ‘checken’ and ‘Recky’ for ‘chicken’ and ‘Ricky’ for example and with the exception of ‘car’ becoming ‘cur’ these are all Scottish influences (anyone doubting any of this should watch ‘Trailer Park Boys’ on NetFlix). Of course it will be difficult finding a reliable source proving this despite it being blatantly true. Overlordnat1 (talk) 03:33, 24 May 2022 (UTC)

Chart usefulness
There is a chart used on this page (File:Atlantic Canada IPA chart.PNG) labeled "Averaged F1/F2 means for speakers from N.S., N.B., N.L." Since there is no explanation of what the "Averaged F1/F2 mean" is or what it signifies, I would argue that this chart provides no useful information whatsoever. I propose to remove it unless someone can convince me that it has any usefulness. WikiDan61 ChatMe!ReadMe!! 12:27, 7 April 2023 (UTC)

 * The purpose of this chart is similar to that of the quadrilateral chart with all the vowels on it in the California English page. For the purposes of the article, you can think of F1 as a quantitative measure of how low a vowel is, and F2 as a measure of how front it is (in the IPA sense of height and front-ness). The YouTube videos "Formants - Why are Voices and Vowel Qualities Different?" and "Vowels 201: The true meaning of the vowel space (feat. nasal vowels, rhotacization, ATR, semivowels)" go into more depth if you want. Tyrui (talk) 11:57, 16 April 2023 (UTC)
 * Doubtless the F1/F2 measurement has some meaning, but if the article does not explain it, then the chart has no meaning to the reader. WikiDan61 ChatMe!ReadMe!! 22:59, 16 April 2023 (UTC)
 * In the absence of any significant expansion of the usefulness of this chart, I have removed it. WikiDan61 ChatMe!ReadMe!! 12:35, 25 April 2023 (UTC)
 * I'm not entirely sure that removing the chart was the best idea; I think it would be better to change the text under the chart. I'd had the Formant page linked, but if it's really necessary, I can (briefly) explain F1 and F2 in the caption. I don't think removing the entire chart is a great idea because that chart (if understood properly, of course) concisely conveys quite a bit of information on the vowel system used in the Maritimes. Tyrui (talk) 03:25, 3 May 2023 (UTC)
 * Thank you for point me to the Formant page; I had not known of that concept before. If that link is provided in the chart caption, it actually does lend meaning to the chart that was previously missing. I'll restore the chart with the proper link for context. WikiDan61 ChatMe!ReadMe!! 11:41, 3 May 2023 (UTC)

Survey Questionnaires
A section is needed to explain how Canadian English was studied by using written questionnaires as it pertains to the linguistic usage of Canadians within everyday life. Some examples by Avis and the Survey of Canadian English directed by Scargill Brycewaynego (talk) 21:07, 13 April 2023 (UTC)

Yod-dropping in B.C.
@Jyqwang You wrote the following line:

"It is only after alveolar consonants (/t/, /d/, /n/, /s/, /l/) the /j/ is then dropped (e.g. duke, new, tune)"

This seems typical of North America, especially among yod-dropping dialects, but I notice that the list doesn't include the palatals /t͡ʃ/, /d͡ʒ/, /ʃ/, /ʒ/, and /j/, the dental /θ/, and the rhotic /ɹ/. If this line is meant to imply that yod-dropping really does only happen after alveolars (and not in the environments I listed), I think it should put emphasis on where it doesn't drop because of how common yod-dropping is in North America. On the other hand, if it does include those consonants, I think the line should be simplified or dropped, because that's where you would expect yod to go. If this a typo or something where it's supposed to say that yod is preserved after alveolars, but not after other coronals (similar (I think) to nearby Victoria according to Roeder, Onosson, and D'arcy (2018)), then obviously that should be fixed. (If the source doesn't specify at all, that's fine.) Tyrui (talk) 03:47, 3 May 2023 (UTC)

American-Centric comparisons
I feel as if a lot of the comparisons are directed toward the US. Although its Canadas' direct neighbour, examples should be diversified to add additional understanding to more readers, rather than relying on knowledge of American-culture and lingustics. Moonsoftoday (talk) 12:56, 26 June 2023 (UTC)

Rhoticity in Canadian English
I was wondering if Canadian English is rhotic or non rhotic! How can I learn rhoticity in Canadian English? 47.145.181.198 (talk) 00:30, 26 March 2024 (UTC)
 * Refer to the Article on Rhoticity in English. Mediatech492 (talk) 01:47, 26 March 2024 (UTC)

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Talk:Canadian English


text:
Talk:CD-ROM

CD sector contents
The sync pattern for Mode 1 CDs is 0xff00ffffffffffffffff00ff Is it byte swapped? IMHO this sentance is very confusing. ECMA-130 provides following definition: The Sync field shall consist of 12 bytes recorded in byte positions 0 to 11: - 1 (00) byte - 10 (FF) bytes - 1 (00) byte Besides it's the same for rest data modes too. And why is this line there at first place? Is it one of 2(!) main consequences extracting RAW data? Themabus (talk) 14:24, 21 December 2008 (UTC)

Optics
Why on Earth has no one mentioned the laser wavelength used to read CD-ROMs? I have added it under 'CD-ROM Drives', headed 'Laser and Optics'. Feel free to add more. —Preceding unsigned comment added by 59.91.241.35 (talk) 19:34, 21 March 2008 (UTC)

Spelling
dics are not hard to find Entry at http://www.bartleby.com/61/16/C0521600.html, and the discussion is pretty interesting.

FYI. Philips Electronics decided already 1972 to spell Optical Discs with a c. This was to differentiate from magnetic disks. note. the link given above is broken. Erik Schylander Kirre46 (talk) 21:12, 10 February 2014 (UTC)

Dates
Hello!! When did CDs come out? Some article...

see the compact disk page: 1982 (japan) 1983 (most other developed countries) —Preceding unsigned comment added by Jasen betts (talk • contribs) 10:01, 20 July 2008 (UTC)
 * I just added the year, I too was bewildered to find a page with so much detail and yet no mention of a date! CDs were introduced in 1982, CD-ROM in 1985, as far as I can tell. Playclever (talk) 23:25, 18 August 2008 (UTC)

Formats
Hi-Sierra and Joliet are top-tier formats for cd and ISO images.

Hi-Sierra and Joliet? What are they? How about the various formats of CD images, ISO, BIN etc? I am aware of these things, but not there exact meaning, so any informed addtion would be useful. Rich Farmbrough 10:04, 15 Dec 2004 (UTC)

High Serreia is the predecessor to the ISO-9660 filesystem, (there are only a few minor differences between them)!

Joliet is a Microsoft-developed an extension to the ISO-9660 filesystem which addresses filename length, directory length, and wide character (16-bit) limitations. See the following:

 it's so cool!

The term "ISO" generally refers to a CD-ROM image file, typically used for interim storage of CD-ROM-destined content, generally in ISO-9660 filesystem format (or one of its derivatives). ISO images are sometimes temporarily created by filesystem creation software (mkisofs on Linux), but are commonly used to transfer full CD-ROM images from computer to computer.

Other formats like Ahead Software's Nero (.nrg) formats are essentially proprietary and likely contain additional metadata and features specific to the software.

"CDROMs for the deaf?" Now thats just wrong

We need a disambuigation thing for the Recorder ID / RID, but that means that we actually need an article on the recorder ID..

(Personally, I have not heard about this attempt at big brother)

--Eptalon 22:52, 23 Mar 2005 (UTC)

Form factor
Is it just a coincidence that the CD was invented with a form factor such that their drives could be the same physical size as those of the earlier 5 1/4 floppy disks? If not, then this would mean that the inventors of the CD had it in mind all along that they might be used in PCs. Either way, there should be some discussion of this here and in the main CD article...

--4.245.5.118 23:17, 25 Apr 2005 (UTC)

 * It's just a happy coincidence. According to Kees A. Schouhamer Immink, the size of the CD was chosen based on the cassette tape, i.e. the CD diameter would be about the same as the cassette width. Not because there was any advantage to it, but simply because the cassette was a success. Mirror Vax 08:31, 9 May 2005 (UTC)

 * My understanding was that it was not just that the cassette was a success; it was a success as an in-car format. There was a requirement that it be possible to build CD players that would fit in the same space as a cassette player in a car. Jeh (talk) 09:34, 29 November 2016 (UTC)

Those magnificient bulky CD-ROMs
I see that this topic does not cover those CDROMs of yesteryears that came in special "protective" tray for each CD and could be accessed only by a special CD-ROM drive where any CD had to be inserted into a blank tray. These were initially introduced as a sturdy alternative. I just don't remember their names and can't seem to find it on the net either. So if anyone knows their name, please go ahead and include that piece of history. It's surprising that Wikipedia does not mention this and I thought most of the users around here were computer buffs.--Idleguy 14:16, July 22, 2005 (UTC)

 * I don't remember any CDs that had to be used with one of those drives. Rather, there were drives that required discs to be put in a "CD caddy" because they didn't have trays or regular slot loaders, and I guess some discs might have come with their own caddies. It's still a regular CD inside the caddy, though. Mr2001 16:15, 22 July 2005 (UTC)

 * OK. Thx. Maybe I'll add a word on that in the article. --Idleguy 05:50, July 23, 2005 (UTC)

 * This is interesting. I've never seen that before. Does anyone have a picture? --Mmartins 08:04, 15 August 2005 (UTC)

 * Simply typing cd caddy into images.google gives a view results, this one here looks nice: http://www.pc-911.com/product_images/cd_caddy.jpg
 * You can press the 'buttons' in the lower left and right to open it up to pickup the CD from the inside and the metal-shutter slides away like on 3.5" floppy disk, so its basically like a normal CD case crossed with a 3.5" floppy disk. Only know those things from the time where CD where single speed and a few early CD writers had them two. Heard that BluRay might use them too, however not sure about that. -- Grumbel 23:52, 18 October 2005 (UTC)

 * We had one of those at school in our first CDROM drive (single speed, SCSI, size of a small car, hooked up to a pizzabox 386-SX...). It seemed so awesome and futuristic :D running Encarta and having it flick into fullscreen lo-rez VGA while attempting to play the postage stamp videos. So yeah, they be real. Back in the day you wouldn't have had more than a handful of disks (Encarta was many, many times larger than the 386's hard disk, and probably rather expensive), partly because there weren't many to be had and partly because they held a comparitively large amount of info (not spamming it all away on FMV, programs that need >64mb just to load, and the like). So either quite occasionally swapping what's in your caddy, or getting two or three spares, wouldn't have been such a hardship. I remember getting our first "modern" PC, and it had a tray-load 2x drive, it seemed like a further leap into the future... what, it works just like the stereo does, it doesn't need a caddy? What's next, teleportation? Jetpacks? A modem that you can do something useful with? 193.63.174.10 (talk) 14:33, 18 November 2009 (UTC)

 * A quote from the article:

 * "...whereas caddy owners could still play loose CDs by loading them into an openable cartridge which was then inserted into the drive (this of course defeated their entire purpose and was more fiddly than loading a disc into an ordinary drive)."

 * I don't see the defeating-of-purpose here. Just put the CD in the caddy and leave it there forever, right? --67.172.99.160 19:44, 26 December 2005 (UTC)

 * Then you'd need to buy a new reusable caddy for every disc you owned...

 * The problem was, most people didn't buy more than the one or two caddies that came with their drive, and just swapped the disc every time. Normally, you should by a pile, and put your frequently used CD-ROMs in the caddies, leaving one or two empty caddies for all other discs. 66.114.93.6 04:03, 12 January 2007 (UTC)

 * I remember an early form of DVD Burner that worked like that. Seano1 18:34, 10 May 2006 (UTC)
 * DVD-RAM —Preceding unsigned comment added by 69.125.110.223 (talk) 21:15, 8 January 2008 (UTC)

CD-ROM size
I am confused. If 100 MB = 95.4 MiB, why is a "700MB" CD-ROM 703.1 MiB? --Byronknoll 05:39, 19 December 2005 (UTC)

 * I added the following text to the Capacity section: "CD capacities are always given in binary units. A "700 MB" CD has a nominal capacity of about 700 MiB. But DVD capacities are given in decimal units. A "4.7 GB" DVD has a nominal capacity of about 4.38 GiB." --Byronknoll 04:19, 30 December 2005 (UTC)

 * This was discussed many times in the CD-R discussion list and also on the CD-R FAQ. Actually CD-R capacity is specified not in binary units, but in time units. The first CD-R's were specified at 74 minutes of capacity, and because there are 75 frames ("sectors" if you will, but that's a different discussion) per second, a 74 minute CD-R has at least 74 x 60 x 75 = 333000 frames. There were small variations depending on the equipment used by the manufacturer (usually there was a bit more space than 333000 frames but the extra space was different between individual discs and brands). When used in mode 1, this gives 333000 x 2048 bytes = 681984000 bytes. Just like with hard disks, manufacturers like to use decimal megabyte to make the discs seem bigger so they printed "680MB" on the packaging. But in binary megabytes this is equivalent to just a little over 650MiB. Jac Goudsmit (talk) 07:14, 29 November 2016 (UTC)

 * For the same reason that a videotape that holds about 243 minutes of material is sold as a "four hour" one. It's easier to say/remember, and means the customer doesn't feel bilked by variations in the manufacturing process. In the early days I had a load of CDRWs of the same, cheap brand for backup purposes... QA set the various batches with permissable write speeds of 2x and 4x, and true capacities between 652~660MiB. But they were all sold as "2x, 650mb". 193.63.174.10 (talk) 14:37, 18 November 2009 (UTC)

 * additional: the people making the labels are both lazy, and pay poor attention to detail - i've seen all manner of sizes listed before - 680mb, 730mb, and others, all on standard 74 and 80min discs... Never mind "MiB" being pretty much something made up by wikipedia and some other people who thought the existing units (developed in an age when computer and SI terminology rarely crossed paths) were too confusing to joe average, and the best way to solve it was to make things even more complex. 77.102.101.220 (talk) 23:35, 31 January 2010 (UTC)

CD-Rom Mass Production
I often ask "How are CD-Roms made?" and people invariable answer "They are pressed!" but then cannot elaborate. Google'd the top a little but could not find much in the way of results. Can anyone add something to describe the manufacturing process?

They are more like "stamped", because the process happens pretty fast. 66.114.93.6 03:58, 12 January 2007 (UTC)

They are injection-molded polycarbonate. The mold cavity is closed, the poly is injected, and the cavity is cooled briefly before opening. In the early days, molds closed for as much as 30 seconds per disc, maybe more. Modern molding machines can spit out a disc every 3 seconds or so.

cd disk
don't call it a cd-rom disk. CD already stands for compact disc

1 and 0 encoding
Regarding this sentence;
 * The light/dark and dark/light (pit edge) transitions are translated into 1 bits, the areas with no transitions are translated into 0 bits

Where did this come from? On what level is it supposed to be true? It might apply at the 8-14 encoding level, but it's pretty misleading in that one might read it and reasonably assume that it applied to the file information read off the disk, when in fact there are many layers of encoding between the file information and the bottom (8-14) encoding. Fourohfour 21:01, 4 April 2006 (UTC)

At the lowest level, the eight-to-fourteen modulation is based upon run length encoding of 3 to 11. No pit edges may occur closer then three clock ticks, nor greater than 11 clock ticks apart, and the channel's native frequency (4.3218MHz for CD playback at 1X speed). The EFM employs NRZI, which encodes pit-to-land and land-to-pit transitions as ones in the EFM bit pattern stream. You are correct that there are several layers of encoding and error correction on top of this foundation (CIRC, layered error correction for CD-ROM, etc).

"To put the CD-ROM's storage capacity into context ... "
The whole section describing the size of a CD-ROM in terms of novels seems unencyclopedic, and does not really add any useful information to the article. Anyone wishing to contextualize the size of a CD-Rom can do so themselves with readily available data. Furthermore, the novel example is not based on actual data (such as the actual size of the average novel) but rather on mere conjecture. The section should be removed unless it can be enhanced to add value to the article in an encyclopedic manner. 199.74.100.30 17:45, 28 April 2006 (UTC)

 * Perhaps you are right that the figures for the novel given should be backed up a little more strongly. However, as an example, it has a purpose. Sure, people could "work out" such stuff for themselves given the information (assuming they have reasonable intelligence), but why should they have to? We could reduce and remove lots of stuff from various articles on the basis that people could derive the omitted facts from the remaining information, but how quick or easy would this be? An encyclopedia article does not have to be dry and pared down to the bare minimum to fulfil its purpose. Fourohfour 19:30, 6 May 2006 (UTC)

 * I agree that information like this is indeed useful in an encyclopaedia. The 14th Britannica article on protoplasm,  for example, says of a creature that it is 'about the size of a shilling-piece';  ho ho.
 * But I'd like to tighten it up a bit - words are not 10 letters on average, and the average novel is more than a centimetre. John Wheater 11:03, 21 February 2007 (UTC)

 * I think it is very appropriate to tell readers in simple vivid terms how much plain-text info a CD can hold compared to ordinary plain-text books -- to very clearly make the point that the volumetric efficiency is greater by orders of magnitude, and so is the economic/materials efficiency. The details of how this comparison is made are not important -- if anyone thinks they have a better way to make this basic point, please suggest it here for everyone to consider. -69.87.204.244 14:44, 6 March 2007 (UTC)

Speed
I think there was 16x speed too, wasnt there? I dont see it on the list, maybe someone could add it...

 * I (still) have a 24x, which is not on the list either. It could be that the list wasn't meant to list every speed known to man? 66.114.93.6 04:08, 12 January 2007 (UTC)

The transfer speed section has a confusion between Megabits and Mebibits. I can not correct it as I do not know if the 1x speed is 150x1000 bytes/second or 150x1024 bytes/second.

The speeds are implementation-dependent, and vary from manufacturer to manufacturer, model to model. It's largely irrelevant for CD-ROM at this point, but there have been 1X, 2X, 3X, 4X, 4.5X, 6X, 8X, 10X, 12X, 16X, 20X, 24X, 32X, 48X, 52X, and probably others (including, of course, all the partial-CAV and CAV speeds). I wouldn't bother listing all the speeds.

1X (Real-time) in CD equates to 75 sectors per second; for CD-ROM Mode 1 tracks, this is 75 sectors per second * 2048 bytes user data per sector = 153,600 bytes per second.

Indeed. I have corrected it respectively on CD-ROM, CD-R and there also was some reference to it on DVD page. ArivaldH (talk) 17:28, 24 June 2008 (UTC).

Can anyone fix the Transfer rates section so that the MB and Mb are clear? I think they are being used interchangeably, which isn't right. —Preceding unsigned comment added by 97.92.67.218 (talk) 16:50, 21 October 2008 (UTC)

 * Further to all this, may I draw your attention to the last part of the "Standard" section, from which I quote:
 * "12x drives were common in April 1997. Above 12x speed, there are problems with vibration and heat. Constant angular velocity (CAV) drives give speeds up to 20x but due to the nature of CAV the actual throughput increase over 12x is less than 20/12."
 * Why the heck are we still using an info statement - probably pulled verbatim from elsewhere - that appears to date from TWELVE AND A HALF YEARS AGO? When it's a fairly mainline article about a major type of media, which has undergone massive redevelopment in the intervening years? Heck, even by sometime in '98, 24x drives (aka 10-24 speed, as they baselined at 10x) had been around long enough and were common enough that I had a _spare_ one lying around, that I was able to put into a largely-salvaged P166 system in my school's upper form common room. Most systems you'll find these days will be able to break 48x, or 24 in portable drives.
 * I'm laying off the "being bold" in this case in case there's some _good_ reason for not updating this, but I can't think what it is unless there's been an abject failure to find any notable document that can be linked as source for the newer info. (In which case, let me put it onto a general-CD-info page on my newly upgraded-with-domain-name geocities site, and someone else can quote from and link to it ;). Does it still count as O.R. when it's easily demonstratable by anyone with a common or garden PC and a stopwatch? 193.63.174.10 (talk) 15:59, 18 November 2009 (UTC)

First computer CD-ROM
I've read in some portuguese articles that the first computer in the world to have a CD-ROM was an MSX home-computer made by Philips. This information would be very important to this article provided it is true. Could someone find more information about it? Regards Loudenvier 16:51, 12 September 2006 (UTC)

 * I can't answer your question - but I CAN give you some other history that you might find interesting.

 * I actually worked on the team at Philips Research Labs (in Redhill, Surrey UK) who produced the first ever working CD-ROM.

 * We took a very early Philips audio CD drive and modified it to connect up to a 68000-based 'home computer' research prototype called 'C.H.R.I.S' which we'd designed and built in-house. The first ever CD-ROM disk was pressed on the Philips audio disk production line and just 50 of them were made. The huge capacity of the CD-ROM was a bit of a challenge for us because our biggest hard drives were only 20Mbytes and the CD-ROM could hold 600Mbytes or so.  We quite simply had no way to author 600Mbytes of data.  Data went to the audio disk factory on VAX-formatted 9 track magnetic tape - but we needed random-access to stand a chance of getting this together.  We decided that a good application to try would be a dictionary - but we quickly realised that this would be a massive data-gathering exercise - so for research purposes we decided to do just one letter (we chose 'O' - for reasons now lost to history)...it was still an insane amount of work.  The idea was to have word definitions (including links much like Wikipedia's), synonyms and antonyms, images (where apppropriate) and audio samples for pronunciation.

 * My job as a junior engineer was to write a paint program for an artist to use to paint the pictures. Remember, this was in an era before you could buy paint software (except in specialised systems for TV production houses) - this was also before the invention of the mouse.  My paint program used a digitizing tablet but I believe the demonstration system for the CD-ROM used a touch-screen.

 * We employed a contract artist (who'd never sat in front of a computer in his life) come in and learn how to draw using my software. He painted an Oaf (our favorite image), and Oak apple, an Oak leaf and an Oak tree...and a bunch of other things beginning with 'O'...and much, much later...an Oyster.  Our office secretary (who had a very nice speaking voice and a 'posh' English accent) read out all of the words (it took her a LONG time!) and the entire team took turns to type in the text (which took FOREVER).  100% of the software was custom-written for the demo - the entire C.H.R.I.S operating system - everything.  I recall that David Penna wrote the bulk of the demo software - including some nice features like antialiased fonts which were way ahead of their time.  Everything was written in C.

 * As I recall, most of the 50 disks we pressed worked - and 50 more were later pressed with more pictures, etc. As far as I know, none of those original disks survived (what I wouldn't give to have one of those!).  The system was taken to a variety of trade shows and shown off to visitors to the research labs on dozens of occasions.  Eventually, the team moved on to look into 3D graphics (my part) and into CD-ROM standards and authoring tools.  Originally, we anticipated software on CD-ROM being interpreted from some kind of intermediate code rather than being raw machine-code because we believed that CD-ROM 'players' would be stand-alone machines connected to TV sets that would contain a variety of CPU types.  This never really took off because the PC revolution hit us and pretty much all of the cool standards we drew up were blown away in favor of the (lame) "just like an MS-DOS file system" that we're stuck with to this day.

 * Whilst the audio CD was a joint effort between Philips and Sony - I don't recall who put the first CD-ROM drive into a production computer. We certainly made a variety of home computers - and we did make an MSX machine - so your suggestion is quite plausible.  But I really don't know for sure.

 * SteveBaker 20:53, 29 September 2006 (UTC)

 * Steve, could you add a date to this information, which I'd like to see in an article. John Wheater 10:49, 21 February 2007 (UTC)

 * You mean a date to when the work was done? I'm not sure precisely.  We started on it before the first Philips audio CD player hit the market - but not long before - so it would have had to be 1981 or 1982 or so - but I'm not 100% sure. However, I don't think you should write an article based solely on what a fellow Wikipedian says in a Talk area.  You need references that other people can check - and frankly, I don't have any or I would have written the article myself. SteveBaker 13:51, 21 February 2007 (UTC)

 * I too don't think I should write this article! Indeed it never crossed my mind to do so.  But, ahem, I think maybe you should, some time in the next forty years or so.  The thing is, your narrative is what historians call a primary source.  When Niels Bohr wrote his article on the atom for the 14th Britannica, he spoke from his own knowledge;  CD-ROM history is less important, but worth having on record.  And firsts are an important element of history.  Maybe what is needed is not an article, but a history section in this article, as a third-person detached narrative, naming those involved, citing 'personal knowledge of Steve Baker' as the reference - the sole reference if there really is nothing else, though surely the Philips records must show something.  And then someone would chip in a bit of Sony history, and so we'd wiki on into the sunset... John Wheater 16:28, 21 February 2007 (UTC)

Longevity
I think it would real nice if some info about the longevity of CD-ROM for long term archiving is included in the article : Jebrennan 03:27, 7 December 2006 (UTC)

 * It's a fairly controversial subject. Some CD's (not really CD-ROMs necessarily) were made with some kind of cheaper aluminium layer.  If there was even the tiniest pinhole in the layer of aluminium, it would slowly grow by a weird process something akin to surface-tension in liquids) until it covered enough area to cause a mis-read.  If there were sufficiently few of them, the CD's error correction processing would repair the data stream - but this only works if the hole doesn't grow too big - if the holes are not positioned fortuitously - and if there are not also too many surface scratches.   Eventually there are too many errors and the error correction system would be overwhelmed.

 * But it's hard to place a definite lifetime on the CD because so much depends on where the holes are - how old the disk is - and how much usage it has had. I've had disks from that era fail in less than a year. Once the problem became really well known, most of the fabrication plants tweaked their processes to eliminate the problem - so I doubt that modern CD's suffer from the problem.  Aside from that issue, a CD that's left in storage in a dark place - propped up on it's side and supported by the center hole - should have an enormously long shelf life.  I don't think an upper limit has ever been established.  The very first audio CDs I ever bought still play just fine (Dire Straits "Brothers in Arms", some Glen Miller and some Bach fugues), Those were bought on the first day that consumer CD players and disks went on sale - only to Philips employees and only in our "Staff Shop").  Those are probably amongst the oldest mass-produced consumer-grade CD's in existance and they still play just fine.

 * Recordable disks are a different matter - they work totally differently from mass-produced disks - I have no idea how long they might be expected to last.

 * SteveBaker 23:36, 28 January 2007 (UTC)

 * Personal account: It's highly variable and dependent both on manufacturing and storage. I have been tooling about with disc burning for neeeearly 10 years now (first burner Xmas '99). My first ever disk, on the quite high quality sample disk included with the burner (yes - it was THAT novel at the time, that they had to include samples in case you couldn't buy blanks straight away or were just THAT eager to try it... like I was!) still survives. Other disks burnt at various points in between show a mix of survival, failure, and heading towards it. Even some that are only a couple months old have poor readability if burnt badly, on cheap media, or left in the sun. I try to only use good quality blanks these days as I write far less disks that I used to. It's not worth the risk. A great many MP3 backups that I wrote over the years - overburnt out to 713mb on cheap media, because I couldn't afford to upgrade my hard disk - have serious amounts of unreadable files. Being kept 2-up in slim cases, themselves 2-up, in an open rack facing a window that catches the morning sun hasn't helped, either. The "archival quality" claims of the expensive types, if they are burnt at low speed, and kept in a dark, constant moderate-to-low temperature, low humidity environment in sympathetic cases, are probably closer to truth than lie (though who's going to sue if they don't meet the "200 year" claim?). Everyday use of optical media - particularly affordable optical media - rarely meets these standards, however.
 * The worst examples I've seen of disk degradation, however, match with the example above. It's literal "disk rot". Many cheap CDRWs I bought as multiple-generation rolling backup media eventually succumbed to it... probably because they had dull grey Alumin(i)um backing to their phase-change layer. At some point, a little pinhole appears... and poof... your data at (and largely after, as they were "image" backups) that point has gone. At one time I had piles of these things, each with a little marker-pen note saying whether it was "all OK", or to what capacity it could be safely written, ie where the hole was. They seemed to get slowly worse over time, so the holes must have been growing. I've also got a few pressed audio CDs that are succumbing to rather bad examples of rot from the outside edges in (poor sealing). They are all mid 80s or early 90s releases - oddly, two by Bon Jovi (and another by Aerosmith). Therefore it's going to be a while before they become unplayable, as they were transferred from LP and only about 2/3rds of the maximum capacity is used.
 * An interesting case of CDR fade in action though is a pair of some pale green (or at least, they're NOW pale green) generic type I burnt a double compilation of music onto. A CDROM drive and PC disk will just start throwing CRC errors and you won't get much idea of what's going on other than it's broken. These ones however... they really send the audio error correction hardware into overdrive. Very little skipping, but, oh, the noise level and the crackling. It fades in and out, and at times sounds like a poorly tuned AM station that's somehow in stereo. The pretend pit / land record must be literally fading away to the point where it can't be detected at all in places, and the hifi has to fudge the signal to cover it (amazing it was still able to track, in fact). Imagine that happening to your data - and to it's error correction code, too. There's only so much fuzz that can be tuned out by ECC. And this after only... I think it was something like 7 years? I've got audio cassettes and VHS tapes 3 or even 4 times older than that which still work fine (indeed, a hard disk that's almost 3x that still works), and vinyls that are much much older still that sound good. The disks weren't abused, they may have lain in the sun once or twice, but... they had full labelling over the top edge, and tended to live in a black-backed mini case (one each) with an opaque inlay over them, limiting their exposure. It's just not a reliable medium, if you don't invest in top notch disks.
 * (OTOH some really cheap crappy ones have survived a-ok, and one or two major-seeming brands - that i won't touch any more - die quickly. The moving and shaking behind the scenes in disk-fab-land is a murky business. All you can really do is try to improve your chances, rather than getting a guarantee. Best you can do is print your archival stuff with carbon pigment onto acid-free paper and put it in a fire safe. Buried inside the tip of everest.) 193.63.174.10 (talk) 15:44, 18 November 2009 (UTC)

I'm glad to find some information about lifespan in this Talk section, but how come it doesn't seem to have any mention in the main article? From my own (poor) attempt in trying to research how to find out how to back up my computer, it sounds like HDDs, DVDs, and CDs all are extremely failure-prone and that you can't actually ever back anything up without printing it out to paper. The DVD and Hard disk failure articles both mention different numbers and sources for lifespans, and I'm just really confused if it's even possible to rely on technology at all for things like family photos (at least without having to spend a lot of money to make dozens of copies over and over again)...I hope the reliability of storage can actually catch up to the fast-increasing capacity and that some research organization will find some definite numbers on which consumers can rely. Zeniff 21:47, 14 May 2010 (UTC) —Preceding unsigned comment added by ZeniffMartineau (talk • contribs)

File Name Length
When burning a CD, the CD format seems to limit the length of file names. If someone knows the rules, it would be great to have it here. Also, there seems to be a limit to the number of characters in the title of a CD too. Thanks. Jebrennan 03:27, 7 December 2006 (UTC)

 * No need to clutter up the CD-ROM article with that kind of information, while it is available in the correct articles: Universal Disk Format, ISO 9660, Joliet (file system). Note that there's no such thing as a "CD format", but in fact more than one CD-ROM file system.
 * On a personal note, if you feel the file naming is too limited for your purposes, I'd suggest you use a better CD/DVD authoring software that supports UDF (IMHO, ISO9660 and Joliet are outdated and should only be used when you have to -> on old players or operating system.)--87.122.52.27 16:43, 23 January 2007 (UTC)

When was the first cd rom produced? What about the history of adoption of the format?
Trollderella 08:13, 14 December 2006 (UTC)

Scroll up a bit and read my comments under "First computer CD-ROM" - I actually worked in the group who produced the first ever CD-ROM. Sadly, I can't write about it for the article because that would be OR. SteveBaker 23:11, 28 January 2007 (UTC)

Read-only "media"
It is also debated whether the correct terminology is read-only memory or media. It is generally accepted that, in technical terms, media is the correct terminology. However, due to the widespread use of ROM to refer to other devices such as EEPROM and Flash-ROM (where memory is the correct terminology) most people define CD-ROM as also being memory as it sounds like the abbreviation is from the same origin.

I have removed this unreferenced and rather weaselly and spurious assertion (and other mentions of it) from the article. Plugging the term "compact disc read-only media" into Google returns a piffling 72 unique results, compared to 232,000 for "...memory". This suggests the "media" interpretation of the acronym is far from "generally accepted". FOLDOC, OED and Webster's all agree "memory" is the correct term. ~Matticus TC 20:16, 28 January 2007 (UTC)

 * (As I've said previously - I worked on the team that made the first CD-ROM). The term 'ROM' - meaning "Read Only Memory" was in common use a decade before we came up with the CD-ROM.  There were already lots of kinds of ROM - 'PROM', 'EPROM', etc.  The name 'CD-ROM' came about in the obvious way - from taking the name of the audio disk "CD" and tacking on "ROM".  So it's definitely 'Memory' and not 'Media'.  SteveBaker 23:18, 28 January 2007 (UTC)

Like many things, popular acceptance has asserted one over the other, so the number of links on Google isn't really a valid measure of 'correctness' in this sense (especially as the Google algorithm will naturally lean towards the currently indexed pages). I do however accept Steve Baker's comment and defer to his closer knowledge on this subject. Having said that, I worked in PC hardware when the CD-ROM was released and had an intimate knowledge of the market and the coverage in press. Whilst most of those paper-based arcticles have no on-line archives going back that many years (there is no call for them), I do not think it valid to ignore the large number of people who, at the time, believed (rightly or wrongly) that 'media' was the more correct definition. I did endeavour to reference my original statement, but as already pointed out, widespread use of the 'memory' acronym has rendered the 'media' use somewhat outdated. As you will notice, Steve also agrees with my statement that the reason the 'memory' was chosen/accepted was because of the widespread existing use of other 'ROMs'. My proposal is to rewrite my original statement in a more 'neutral' manner indicating that the debate is now somewhat moot because of the general acceptance of 'memory'. This should ensure it is not open to being interpreted as weaselly. Please enter comments on the subject here and I will endeavour to post at some point in the next few days. DanMatthewsUK 12:48, 16 February 2007 (UTC)

Duly amended as per my statement above. DanMatthewsUK

 * I was about to bring that up when I saw this. I can still see problems with it.  For a start it is entirely unsourced - just who says that precisely?  Secondly it does not strike me as even being correct.  If you were going to argue along this line the correct term would be compact disc read-only medium - i.e. the singular term.  However even then I doubt its validity.  Historically memory has always referred a broad spectrum of devices, not merely random-access technologies - if that was not the case the very term "RAM" would be superflous.  In the absence of a reliable cite I suggest that entire point should be snipped since it strikes me as someone with an axe to grind rather than a real point. CrispMuncher (talk) 19:18, 26 January 2010 (UTC)

 * I was about to say exactly the same thing on reading that paragraph. "Memory" can refer to any storage device - modern usage to refer to main memory (RAM) does not alter that.  Since it is obviously still problematic and still has no source backing it up I'll remove that paragraph completely. Minority Carrier (talk) 16:05, 31 August 2010 (UTC)

 * I don't understand the line of argument for not having the "media-section" included. First of all, I see Wikipedia as a source of knowledge. A section about this discussion, that is short, consise, and does not interfere with the rest of the article, will only add to the knowledge provided, not confuse it! Even if the term is wrong, it has still been used, or at least suggested. Secondly, it is argued that memory may refer to "any storage device", thus also a CD-RO?. Yet, you don't buy a computer with 4 GB of random-access-memory and 500 GB of harddrive-memory. Likewise, I've never heard anybody state that they have a bookshelf full of book-roms, each with 500 pages of memory, although that could be a technically correct term. In computing, storage and "memory" are usually considered different entities, even if a general definition of memory may cover them both. I see CD-ROMs as storage MEDIA, and consequently don't think the term "memory" is appropriate, as in the case of "harddrive-memory", or plain old fashioned book-roms.

 * Judging from Steve Baker's comment, the term was coined more as a "catch-phrase" in a time where many types of ROM were widely used (Regular ROM's, PROM's, EPROM's, and later, I guess, EEPROM's). Since this is the case, I fully accept that "Compact-Disc Read-Only-Memory" is the original, intended, and in that sense correct term. But I don't see any reason to neglect the fact, that in "common computer language" the term is misleading, which has caused debate of the CD-ROM acronym. This brings me back to the first argument, that wikipedia is a source of knowledge, which should be restricted by personal preferences! Jacobmelgaard (talk) 06:38, 11 October 2010 (UTC)

 * The naming section would have some traction if there was any source for it. This has been under discussion for over three years and none has been forthcoming.  Without that is it little more than a rant by a random editor of the opinion that the acronym is somehow inaccurate.  The argument about book-roms etc is nothing more than a straw man - the meanign is clear from context.  Yes, early hard drives were referred to as memories: it is onyl with mdoern usage that the term has fallen out of favour.  That does not make it any less correct. Minority Carrier (talk) 04:47, 16 October 2010 (UTC)

How is the rate of 150 kB/s calculated?
How is the 1x rate of 150 kilobytes pre second calculated? Is the unit SI base 1,000 or base 1,024? —Dispenser 01:18, 19 February 2007 (UTC)

It is 150 KiB per second. It is described on Red Book standard page and on CD-ROM page (yes. As of Today (24 Jun 2008) it is. ArivaldH (talk) 17:26, 24 June 2008 (UTC)

 * If so, the article has many errors in it. —Preceding unsigned comment added by 71.167.65.179 (talk) 03:17, 14 October 2009 (UTC)

"By comparison, the bit rate of a "1x" data CD is defined as 2048 bytes per sector × 75 sectors per second = 150 KiB/s, or approximately 9.2 million bytes per minute."

 * To clarify - it's exactly 153,600 mode-2 user bytes per second. 176,400 for audio, 175,200 for mode-1, and 183,750 overall system bytes when you consider the error correction (or mode-1, audio...), subcode, etc. Convert these to your chosen units as you will. 77.102.101.220 (talk) 23:47, 31 January 2010 (UTC)

recording at high speed
"Recording data CDs at very high speed (40x) can be done without losing information. However, if done the same with PlayStation or Audio CD it will result in an unreadable PlayStation disc or an audio CD with lots of clicks because there are no error correction codes and the errors are more likely to occur at high speed recording."

After the first sentence, this paragraph from the current article sounds kind of stupid. It should be deleted or re-written by someone who knows what they are talking about and knows how to write well. -69.87.204.244 14:31, 6 March 2007 (UTC)

slot loading drives and 80mm discs
The article states that slot loading drives have troble accepting 80mm CD-ROMs and that the Nintendo Wii has overcome this problem however recently on my Imac G3 slot loading (2001) I was recently able to use an 80mm disc in it perfectly.

CD-ROM SIZE RELEASE DATES
http://en.wikipedia.org/wiki/Floppy_disk

FLOPPY DISKS PAGE TELLS THE YEAR FOR EACH SIZE FLOPPY DISK THAT CAME OUT. WHY NOT CDS? —Preceding unsigned comment added by 24.188.17.249 (talk) 22:28, 28 September 2007 (UTC)
 * POSSIBLY BECAUSE CDS ONL... ahem, excuse me. Because CDs only come in one main size, and there's probably no clear data on when the 8cm ones (which are essentially just part-recorded 12cm discs, cut down) arrived. By contrast each different type of floppy was basically an entirely new kind of media, from the perspective of formatting, having to have entirely new case designs, and moreover new drives built in order to be able to use them. The difference between a consumer-level 3.5" DSHD 1.4mb floppy and the original 90-ish kb, 8" type made by IBM for its mainframes is immense, and it's only by happy accident you'd ever find a way to read an 8" in a home PC (it can be done, but it's a right bodge and needs particular chipsets, plus a salvaged minicomputer/early micro drive). Whereas the differences between a 210mb 8cm CD, a 12cm one that's merely been burnt to 210mb, or full-up 12cms of 530, 650, 703 and 790mb capacity (63, 74, 80, 90 minute) is trifling and mostly one of trivial set-up detail. Even the difference between a 63 min CD and a DL DVD can be likened to that between a single sided, single/double density drive and a double sided high density one of the same size (5.25 or 3.5")... but in that case, we have release dates for "CD" and "DVD" as discrete classes of 12cm optical disk, and there were no in-between formats such as SSDD/DSDD. The newer drive in both cases will read the disks originally made for the older one, too... The jump from, say, 5.25 inch to 3.5 inch is more like going from CD to Hi-MD. 193.63.174.10 (talk) 15:03, 18 November 2009 (UTC)

DVD to CD size
4.38 / (700/1024) = 6.4

Not that difficult... —Preceding unsigned comment added by Craigblock (talk • contribs) 19:54, 15 January 2008 (UTC)

It says 4.4 GiB, not GB. That is gibibits, not gigabytes. A CD holds 747 MiB (mibibits) or 700 MB (megabytes). 4.4 GiB / 747 MiB = 5.89 (or roughly 6). You are correct, it isn't that difficult, but only if you use the right terms. There are other mistakes in the article where it shows 700 MiB that need fixing as well. I reverted back. Pharmboy (talk) 20:07, 15 January 2008 (UTC)

 * There's a error on that, which might explain the under 6 result. 700 MB is 734,003,200 bytes (700*1024*1024). And secondly, MiB should be mibibytes, not bits. 85.217.14.225 (talk) 10:00, 3 November 2010 (UTC)

A CD holds 700 * 1024^2 bytes. A DVD holds around 4485 * 1024^2 bytes. 4485/700 = 6.4. A DVD holds 6.4 times the amount of checksummed data as a CD. —Preceding unsigned comment added by Craigblock (talk • contribs) 23:14, 15 January 2008 (UTC)

 * What the hell, people. Let me break this down for you before we get hung up on mebi-bibble-bytes and whatever. Using the same units for both...
 * Large type of DVD recordable ("minus") vs 74 minute CD: 4488 "MiB" vs 652. 6.88x larger.
 * Smaller type of DVD recordable ("plus") vs 80 minute CD: 4483 vs 703. 6.37x larger.
 * Figures arrived at by empirical means, I'm afraid, but I think O.R. is probably acceptable for reasons of discussion?
 * I don't know the hard limit for storage on a single-layer pressed DVD but we can probably assume it to be similar. Somewhere between 6.3 (rounding down because overburning is entirely usable on a CD but a bad idea for DVD - i've found 710 and ~4400 MiB to be acceptable limits of reliability) and 6.9x that of a CD, depending which particular varieties of apple and orange you're choosing to compare. Call it 6.6x if you want a single easy figure. Was that so hard?
 * Personally if splitting archive files for portability I'll bring down the axe at 640 MiB, which is a bit of a waste with 80-minute CDRs but means you can also put 7 of them onto a DVDR at once (4480 MiB, fitting pretty much any blank out there... bit of a risk of errors in the last 80mb, but if it's for short term file transfer use and burnt at 8x or less the data usually survives).
 * Dual layer disks and DVD-RAMs are an entirely different matter. The only DLs I've used were 8152MiB (not quiiiiite 8.0GiB, probably for filesystem reasons as much as anything). Giving us 11.6 to 12.5x that of a CDR. You'll likely want to settle for 12x (and 12x 640 MiB, at that) though, given how goddamn unreliable they are. RAMs, I have no idea, it's officially "3.8gb", which probably equates to ~3624 MiB in practice, or ~5.3x CD. (Or 6.5x a 63-minute mastering CD).
 * That good enough for you? 193.63.174.10 (talk) 15:16, 18 November 2009 (UTC)

technical specs
Removed the following from the Bit article, in the "storage" section:

“On storage devices like 1,200,000 nm-thick CD-ROMs, a bit is mechanically etched by intensive laser beam as a pit about 168 nm deep and 670 nm wide of variable length (depending on data type) on concentric tracks spaced 1,600nm apart. The total length of the track in a 650 MB disk thus may span several kilometres. The light of the reading laser is reflected back into the laser, which then picks up that light with a sensor. The transition between a pit and a ground means a 1, and a short period of time on the same level is a 0. No more than 11 consequent zeros may occur, because the laser receives no state change during consequent zeros and has to rely on a timer to know the amount of zeros, whose accuracy is limited. CD-Rs work on the same theory, except that they use dyes instead of pits and ground. ”

Notice how the numbers differ from those in Compact Disc. This stuff here may be of interest. --Jerome Potts (talk) 04:46, 4 October 2008 (UTC)

Untitled text moved from above table of contents
15:25, 4 October 2009 (UTC) Will someone please tell me if you can create a 'read only' CD which then allows the next used of the CD to be kept from changing anything on the original CD? Like if there is a letter copied onto the first CD, can it be entered and changed by someone else later if it is supposed to be 'read only??' thanks! oct 4, 2009. —Preceding unsigned comment added by 76.190.253.227 (talk) 15:25, 4 October 2009 (UTC)
 * Weeeelllll you've got a few options. First one, if you can stand the massive inconvenience and cost of not being able to change ANYTHING on your 10-cent disc after making it, is just to put the files onto a vanilla, write-once CDR... nothing short of actually damaging the disc will then be able to alter anything, and said alteration is better described as "destruction". If for some wierd reason this isn't possible you could just try making the file itself have "read only" properties (though this is generally only a minor irritation to human users, who can hit the "are you sure" button or turn the attribute off - it's only really effective against programs) either before or after th burn depending on whether you're doing CDRW/multisession CDR or using a packetCD. More effectively you could look into some digital signature/encryption/etc software that will properly secure the file against unauthorised changes, or even reading/access. This will likely cost you quite a bit more than a few extra throwaway CDRs, however. As a final note, I see you can now buy a drive which has built-in data protection and security features... this might be of interest also. Good luck. 193.63.174.10 (talk) 14:13, 18 November 2009 (UTC)

DDDUUUUUUHHHHHHHHH
you guys should atlest mention who made it DDDDDDDDDUUUUUUUUUUHHHHHHHHHHHHHHH... IN THE FIRST PARAGRAPH. AND ACTUALLY SAY THE CD ROM WAS CREATED BY.... BECAUSE NOBODY EVER SAYS WHO —Preceding unsigned comment added by 209.26.59.205 (talk) 16:23, 24 January 2009 (UTC)

== كنت عايزاعرف الفرق بين السى دى روم والسى دى ريتر == Bold text

محمود   mhmoud_202016@yahoo.com

 * You guys are awesome, without true genuine winners like yourself, civilization would simply fall apart. I believe there's a personal account somewhere up above from one of the guys on the original Phillips CDROM prototype team? 193.63.174.10 (talk) 15:21, 18 November 2009 (UTC)

 * OK to be more fair to Mahmoud there... looks like you're after the difference between cdrom and cd writer... well... maybe you're having as much difficulty getting hold of an understandable arabic version as I am an english translation of what you said (one significant word remains obscure). So, let's try to put it in simple language. CD ROM = disc is made in a factory, the data is chosen by someone else and cannot be changed. CD writer is a device you use to create your own CDR and CDRW discs. Alright? :) 77.102.101.220 (talk) 00:02, 1 February 2010 (UTC)

Transfer rate section is in disarray
The section on transfer rate is pretty messed up. I'm not even sure it's self-consistent. Here is my understanding: A 1x transfer rate corresponds to a track speed of 1.2 m/s at all positions on the disc, which corresponds to an angular velocity of 500 rpm at the inner diameter and 200 rpm at the outer diameter. These numbers scale for speeds up to about 12x, I think. Above 12x, drives typically operate in a constant angular velocity mode (constant rpm) so that the drive isn't forced to ramp the motor speed up and down as the head seeks to different positions. In CAV mode, the "x" value refers only to the transfer rate at the outer edge of the disc. At the inner edge the transfer rate is about 2.5 times lower. Thus, a 52x drive spins at 52x200rpm = 10400rpm. Period. Not "up to 26000" as the article now states. And the track speed at the OD is 52*1.2m/s = 63m/s. Period. Not "65 to 163 m/s". I don't have references handy; unless someone gets to it first, I'll at least remove the unreferenced stuff that I know to be wrong. Spiel496 (talk) 05:02, 21 March 2010 (UTC)

Mode 2 Form 1/2 is missing
It would be nice if the 2 different sector formats are described here, incl. why Mode 1 is more common today than Mode 2 Form 1. --RokerHRO (talk) 20:24, 23 January 2012 (UTC)

Unclear scope / overlap with Compact disc and other related articles
The scope of this article is unclear. It sometimes goes beyond the CD-ROM, properly speaking. In particular, this can be seen in the Transfer rates and Copyright issues sections. The CD-ROM is just one of the CD types discussed in these. These sections discuss all types of data CDs.

It seems we don't have a consistent scope in the article. The scope may be CD-ROM-s everywhere, but in different senses. Sometimes in the strict sense, sometimes in the sense of data CD, read-only or not. It is understandable that this article discusses data CDs, as the CD-ROM was the first form of (general) data CD, but I'm thinking it's probably best to move most discussion on data CDs in general to Compact disc. Otherwise, if we keep using "CD-ROM" in the sense of data CD, we need to make that sense clear in the lead. --Chealer (talk) 15:10, 9 March 2013 (UTC)

512 byte sector size for older Sun and DEC machines
Should the article mention that early CD-ROM drives for Sun and DEC machines (and maybe other Unix flavour machines) used a 512 byte sector rather than the PC / MSDOS 2048byte sector. This required special versions of the CD-ROM drives (typically with SCSI interface), see:

http://sites.inka.de/pcde/help/dec-cdrom-list.txt http://www.pimpworks.org/sun/backgrnd.html

John a s (talk) 19:08, 22 April 2014 (UTC)

What format is the address given in? I've got lots of questions on this.
Does it specify the byte number of the first byte of the sector, or the mm:ss:ff time code? Does it specify the address at the start of the header of that sector (the first byte of the sync pattern of the header of the sector), or does it specify the address at the start of the data section of the sector, or does it specify the address of the first byte of the address field (in other words, the address field specifies its own address)? Is it a big-endian number, or a little-endian number? — Preceding unsigned comment added by Benhut1 (talk • contribs) 00:44, 3 May 2014 (UTC)

3234 Bytes?
Sorry, but isn't a sector 3234 Bytes? Why can't I find that number on the whole page? — Preceding unsigned comment added by 93.232.209.201 (talk) 18:08, 16 May 2017 (UTC)

External links modified
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Speed Table
It would be helpful is there was an additional column specifying when drives of the various speeds were made available. I came to this article looking for exactly this.

I also own both an NEC 3x and 6x speed drives, which aren't represented in the able, at all. Valgrus Thunderaxe (talk) 01:21, 3 August 2022 (UTC)

title: Talk:CD-ROM


text:
Corinth

Corinth (Κόρινθος, ) is a municipality in Corinthia in Greece. The successor to the ancient city of Corinth, it is a former municipality in Corinthia, Peloponnese, which is located in south-central Greece. Since the 2011 local government reform, it has been part of the municipality of Corinth, of which it is the seat and a municipal unit. It is the capital of Corinthia.

It was founded as Nea Korinthos (Νέα Κόρινθος), or New Corinth, in 1858 after an earthquake destroyed the existing settlement of Corinth, which had developed in and around the site of the ancient city.

History
Corinth derives its name from Ancient Corinth, a city-state of antiquity. The site was occupied from before 3000 BC.

Ancient Greece
Historical references begin with the early 8th century BC, when ancient Corinth began to develop as a commercial center. Between the 8th and 7th centuries, the Bacchiad family ruled Corinth. Cypselus overthrew the Bacchiad family, and between 657 and 550 BC, he and his son Periander ruled Corinth as the Tyrants.

In about 550 BC, an oligarchical government seized power. This government allied with Sparta within the Peloponnesian League, and Corinth participated in the Persian Wars and Peloponnesian War as an ally of Sparta. After Sparta's victory in the Peloponnesian war, the two allies fell out with one another, and Corinth pursued an independent policy in the various wars of the early 4th century BC. After the Macedonian unification of Greece, the Acrocorinth was the seat of a Macedonian garrison until 243 BC, when the city joined the Achaean League.

Ancient Rome
Nearly a century later, in 146 BC, Corinth was captured and was completely destroyed by the Roman army.

As a newly rebuilt Roman colony in 44 BC, Corinth flourished and became the administrative capital of the Roman province of Achaea.

Medieval times
An important earthquake touched Corinth and its region in 856, causing around 45000 deaths.

Modern era
In 1858, the old city, now known as Ancient Corinth (Αρχαία Κόρινθος, Archaia Korinthos), located 3 km southwest of the modern city, was totally destroyed by a magnitude 6.5 earthquake. New Corinth (Nea Korinthos) was then built to the north-east of it, on the coast of the Gulf of Corinth. In 1928, a magnitude 6.3 earthquake devastated the new city, which was then rebuilt on the same site. In 1933, there was a great fire, and the new city was rebuilt again.

During the German occupation in World War II, the Germans operated a Dulag transit camp for British, Australian, New Zealander and Serbian prisoners of war and a forced labour camp in the town.

Geography
Located about 78 km west of Athens, Corinth is surrounded by the coastal townlets of (clockwise) Lechaio, Isthmia, Kechries, and the inland townlets of Examilia and the archaeological site and village of ancient Corinth. Natural features around the city include the narrow coastal plain of Vocha, the Corinthian Gulf, the Isthmus of Corinth cut by its canal, the Saronic Gulf, the Oneia Mountains, and the monolithic rock of Acrocorinth, where the medieval acropolis was built.

Climate
According to the nearby weather station of Velo, operated by the Hellenic National Meteorological Service, Corinth has a hot-summer Mediterranean climate (Köppen climate classification: Csa), with hot, dry summers and cool, rainy winters. The hottest month is July with an average temperature of 28.7 C while the coldest month is January with an average temperature of 9.1 C. Corinth receives about 463 mm of rainfall per year and has an average annual temperature of 18.1 C.

Demographics
The Municipality of Corinth (Δήμος Κορινθίων) had a population of 55,941 according to the 2021 census, the second most populous municipality in the Peloponnese Region after Kalamata. The municipal unit of Corinth had 38,485 inhabitants, of which Corinth itself had 30,816 inhabitants, placing it in second place behind Kalamata among the cities of the Peloponnese Region.

The municipal unit of Corinth (Δημοτική ενότητα Κορινθίων) includes apart from Corinth proper the town of Archaia Korinthos, the town of Examilia, and the smaller settlements of Xylokeriza and Solomos. The municipal unit has an area of 102.187 km2.

Industry
Corinth is a major industrial hub at a national level. The Corinth Refinery is one of the largest oil refining industrial complexes in Europe. Ceramic tiles, copper cables, gums, gypsum, leather, marble, meat products, medical equipment, mineral water and beverages, petroleum products, and salt are produced nearby. , a period of Economic changes commenced as a large pipework complex, a textile factory and a meat packing facility diminished their operations.

Roads
Corinth is a major road hub. The A7 toll motorway for Tripoli and Kalamata, (and Sparta via A71 toll), branches off the A8/European route E94 toll motorway from Athens at Corinth. Corinth is the main entry point to the Peloponnesian peninsula, the southernmost area of continental Greece.

Bus
KTEL Korinthias provides intercity bus service in the peninsula and to Athens via the Isthmos station southeast of the city center. Local bus service is also available.

Railways
The metre gauge railway from Athens and Pireaeus reached Corinth in 1884. This station closed to regular public transport in 2007. In 2005, two years prior, the city was connected to the Athens Suburban Railway, following the completion of the new Corinth railway station. The journey time from Athens to Corinth is about 55 minutes. The train station is 5 minutes by car from the city centre and parking is available for free.

Port
The port of Corinth, located north of the city centre and close to the northwest entrance of the Corinth Canal, at 37 56.0’ N / 22 56.0’ E, serves the local needs of industry and agriculture. It is mainly a cargo exporting facility.

It is an artificial harbour (depth approximately 9 m, protected by a concrete mole (length approximately 930 metres, width 100 metres, mole surface 93,000 m2). A new pier finished in the late 1980s doubled the capacity of the port. The reinforced mole protects anchored vessels from strong northern winds.

Within the port operates a customs office facility and a Hellenic Coast Guard post. Sea traffic is limited to trade in the export of local produce, mainly citrus fruits, grapes, marble, aggregates and some domestic imports. The port operates as a contingency facility for general cargo ships, bulk carriers and ROROs, in case of strikes at Piraeus port.

Ferries
There was formerly a ferry link to Catania, Sicily and Genoa in Italy.

Canal
The Corinth Canal, carrying ship traffic between the western Mediterranean Sea and the Aegean Sea, is about 4 km east of the city, cutting through the Isthmus of Corinth that connects the Peloponnesian peninsula to the Greek mainland, thus effectively making the former an island. The builders dug the canal through the Isthmus at sea level; no locks are employed. It is 6.4 km in length and only 21.3 m wide at its base, making it impassable for most modern ships. It now has little economic importance.

The canal was mooted in classical times and an abortive effort was made to build it in the 1st century AD. Julius Caesar and Caligula both considered digging the canal but died before starting the construction. The emperor Nero was the first to attempt to construct the canal. The Roman workforce responsible for the initial digging consisted of 6,000 Jewish prisoners of war. Modern construction started in 1882, after Greece gained independence from the Ottoman Empire, but was hampered by geological and financial problems that bankrupted the original builders. It was completed in 1893, but due to the canal's narrowness, navigational problems and periodic closures to repair landslips from its steep walls, it failed to attract the level of traffic anticipated by its operators. It is now used mainly for tourist traffic.

Sport
The city's association football team is Korinthos F.C. (Π.Α.E. Κόρινθος), established in 1999 after the merger of Pankorinthian Football Club (Παγκορινθιακός) and Corinth Football Club (Κόρινθος). During the 2006–2007 season, the team played in the Greek Fourth Division's Regional Group 7. The team went undefeated that season and it earned the top spot. This granted the team a promotion to the Gamma Ethnikí (Third Division) for the 2007–2008 season. For the 2008–2009 season, Korinthos F.C. competed in the Gamma Ethniki (Third Division) southern grouping.

Twin towns/sister cities
Corinth is twinned with:
 * 🇮🇹 Syracuse, Sicily
 * 🇷🇸 Jagodina, Serbia

Notable people

 * Anastasios Bakasetas (1993–), Greek footballer
 * Evangelos Ikonomou (1987–), Greek footballer
 * George Kollias (1977–), drummer for US technical death metal band Nile.
 * Georgios Leonardopoulos, army officer
 * Macarius (1731–1805), Metropolitan bishop of Corinth
 * Ioannis Papadiamantopoulos (1766–1826), revolutionary leader during the Greek War of Independence.
 * Irene Papas (1929–2022), Greek actress
 * Costas Soukoulis (1951–2024), Professor of Physics at Iowa State University
 * Konstantinos Triantafyllopoulos (1993–) Greek footballer
 * Panagis Tsaldaris (1868–1936), Greek politician and prime minister of Greece
 * Panagiotis Tzanavaras (1964–), Greek footballer and football manager
 * Nikolaos Zafeiriou (1871–1947), Greek artillery officer

Other locations named after Corinth
Due to its ancient history and the presence of St. Paul the Apostle in Corinth some locations all over the world have been named Corinth.

title: Corinth


text:
Colossae

Colossae (Κολοσσαί) was an ancient city of Phrygia in Asia Minor, and one of the most celebrated cities of southern Anatolia (modern Turkey). The Epistle to the Colossians, an early Christian text which identifies its author as Paul the Apostle, is addressed to the church in Colossae. A significant city from the 5th century BC onwards, it had dwindled in importance by the time of Paul, but was notable for the existence of its local angel cult. It was part of the Roman and Byzantine province of Phrygia Pacatiana, before being destroyed in 1192/3 and its population relocating to nearby Chonae (Chonai, modern-day Honaz).

Location and geography
Colossae was located in Phrygia, in Asia Minor. It was located 15 km southeast of Laodicea on the road through the Lycus Valley near the Lycus River at the foot of Mt. Cadmus, the highest mountain in Turkey's western Aegean Region, and between the cities Sardeis and Celaenae, and southeast of the ancient city of Hierapolis. At Colossae, Herodotus describes how, "the river Lycos falls into an opening of the earth and disappears from view, and then after an interval of about five furlongs it comes up to view again, and this river also flows into the Maiander." Despite a treacherously ambiguous cartography and history, Colossae has been clearly distinguished in modern research from nearby Chonai (Χῶναι), now called Honaz, with what remains of the buried ruins of Colossae ("the mound") lying 3 km to the north of Honaz. The case is made exhaustively in this book, over pages 11-37, wherein it states—after dispensing with a further false association of the ancient city with the island of Rhodes the home of The Colossus of Rhodes, which resulted in its being misplaced for hundreds of years (by "almost 200 kilometers to the south-west," p. 18ff)—in summary, that: "Colossae's various positions on early maps confirmed the confusion over identity [opening section title]. Cartographers positioned Colossae to the west (rather than south-east) of Laodicea7 or, as 'Conos', between Laodicea to the north-west and Hieropolis to the north-east.8 [p. 11] … 'Chonos' or some other guesttimation of the spelling of Honaz12 sometimes subsumed Colossae. [p. 13] … The inhabitants of the immediate vicinity of the ancient site [Colossae, which had ceased to exist] were shackled in bureaucratic tabulation for tax purposes to the town of Honaz. [p. 14] … When Frances Arundell's sketch of Honaz appeared in 1834, the town had descended from the mountain heights [it was a mountain fortress, Honazdağ] but it was similarly labelled, albeit after the fashion of Nicetas Choniates: 'Chonas, … anciently Colossae'.98 [p. 32] … The question was whether Honaz and Colossae were to be equated or separated and whether the contemporary Honaz was the means to pinpoint the ancient… site. [p. 33] … William Hamilton became the one credited with the separation of Colossae from Chonai with the former's location at the mound three kilometers to the north of Honaz.108 [p. 35] … Two photographs of the 'Ruines de Colossae' and 'Chonas' by Henri Carmignac published toward the endif the nineteenth century finally eliminated the concordant visualisation of the places that had been the legacy of Arundell (Fig. 11).113 [p. 37]." For much earlier sources presenting the errant historical opinion, see the next two citations.

Origin and etymology of place name
The medieval poet Manuel Philes, incorrectly, imagined that the name "Colossae" was connected to the Colossus of Rhodes. More recently, in an interpretation which ties Colossae to an Indo-European root that happens to be shared with the word kolossos, Jean-Pierre Vernant has connected the name to the idea of setting up a sacred space or shrine. Another proposal relates the name to the Greek kolazo, "to punish". Others believe the name derives from the manufacture of its famous dyed wool, or colossinus.

Before the Pauline period
The first mention of the city may be in a 17th-century BC Hittite inscription, which speaks of a city called Huwalušija, which some archeologists believe is a reference to early Colossae. The 5th-century geographer Herodotus first mentions Colossae by name and as a "great city in Phrygia", which accommodates the Persian king Xerxes I while en route to wage war against the Greeks in the Greco-Persian Wars– showing the city had already reached a certain level of wealth and size by this time. Writing in the 5th century BC, Xenophon refers to Colossae as "a populous city, wealthy and of considerable magnitude". It was famous for its wool trade. Strabo notes that the city drew great revenue from the flocks, and that the wool of Colossae gave its name to colour colossinus.

In 396 BC, Colossae was the site of the execution of the rebellious Persian satrap Tissaphernes, who was lured there and slain by an agent of the party of Cyrus the Younger.

Pauline period
Although during the Hellenistic period, the town was of some mercantile importance, by the 1st century it had dwindled greatly in size and significance. Paul's letter to the Colossians points to the existence of an early Christian community. The town was known for its fusion of religious influences (syncretism), which included Jewish, Gnostic, and pagan influences that, in the first century AD, were described as an angel-cult. This unorthodox cult venerated the archangel Michael, who is said to have caused a curative spring to gush from a fissure in the earth. The worship of angels showed analogies with the cult of pre-Christian pagan deities like Zeus. Saint Theodoret of Cyrrhus told about their surviving in Phrygia during the fourth century. The canonical biblical text Epistle to the Colossians is addressed to the Christian community in Colossae. The epistle has traditionally been attributed to Paul the Apostle due to its autobiographical salutation and style, but some modern critical scholars now believe it to be written by another author some time after Paul's death. It is believed that one aim of the letter was to address the challenges that the Colossian community faced in its context of the syncretistic Gnostic religions that were developing in Asia Minor.

According to the Epistle to the Colossians, Epaphras seems to have been a person of some importance in the Christian community in Colossae, and tradition presents him as its first bishop. The epistle also seems to imply that Paul had never visited the city, because it only speaks of him having "heard" of the Colossians' faith, and in the Epistle to Philemon Paul tells Philemon of his hope to visit Colossae upon being freed from prison. Tradition also gives Philemon as the second bishop of the see.

The city was decimated by an earthquake in the 60s AD, and was rebuilt independent of the support of Rome.

The Apostolic Constitutions list Philemon as a bishop of Colossae. On the other hand, the Catholic Encyclopedia considers Philemon doubtful.

The first historically documented bishop is Epiphanius, who was not personally at the Council of Chalcedon, but whose metropolitan bishop Nunechius of Laodicea, the capital of the Roman province of Phrygia Pacatiana, signed the acts on his behalf.

Byzantine period and decline
The city's fame and renowned status continued into the Byzantine period, and in 858, it was distinguished as a Metropolitan See. The Byzantines also built the church of St. Michael in the vicinity of Colossae, one of the largest church buildings in the Middle East. Nevertheless, sources suggest that the town may have decreased in size or may even been completely abandoned due to Arab invasions in the seventh and eighth centuries, forcing the population to flee to resettle in the nearby city of Chonai (modern day Honaz).

Colossae's famous church was destroyed in 1192/3 during the Byzantine civil wars. It was a suffragan diocese of Laodicea in Phyrigia Pacatiana but was replaced in the Byzantine period by the Chonae settlement on higher ground

Modern study and archeology
As of 2019, Colossae has never been excavated, as most archeological attention has been focused on nearby Laodicea and Hierapolis, though plans are reported for an Australian-led expedition to the site. The present site exhibits a biconical acropolis almost 100 ft high, and encompasses an area of almost 22 acre. On the eastern slope there sits a theater which probably seated around 5,000 people, suggesting a total population of 25,000–30,000 people. The theater was probably built during the Roman period, and may be near an agora that abuts the cardo maximus, or the city's main north–south road. Ceramic finds around the theater confirm the city's early occupation in the third and second millennia BC. Northeast of the tell, and most likely outside the city walls, a necropolis displays Hellenistic tombs with two main styles of burial: one with an antecedent room connected to an inner chamber, and tumuli, or underground chambers accessed by stairs leading to the entrance. Outside the tell, there are also remains of sections of columns that may have marked a processional way, or the cardo. Today, the remains of one column marks the location where locals believe a church once stood, possibly that of St. Michael. Near the Lycus River, there is evidence that water channels had been cut out of the rock with a complex of pipes and sluice gates to divert water for bathing and for agricultural and industrial purposes.

Modern legacy
The holiness and healing properties associated with the waters of Colossae during the Byzantine era continue to this day, particularly at a pool fed by the Lycus River at the Göz picnic grounds west of Colossae at the foot of Mt. Cadmus. Locals consider the water to be therapeutic.

title: Colossae


text:
Charge of the Goddess

The Charge of the Goddess (or Charge of the Star Goddess) is an inspirational text often used in the neopagan religion of Wicca. The Charge of the Goddess is recited during most rituals in which the Wiccan priest/priestess is expected to represent, and/or embody, the Goddess within the sacred circle, and is often spoken by the High Priest/Priestess after the ritual of Drawing Down the Moon.

The Charge is the promise of the Goddess (who is embodied by the high priestess) to all witches that she will teach and guide them. It has been called "perhaps the most important single theological document in the neo-Pagan movement". It is used not only in Wicca, but as part of the foundational documents of the Reclaiming tradition of witchcraft co-founded by Starhawk.

Several versions of the Charge exist, though they all have the same basic premise, that of a set of instructions given by the Great Goddess to her worshippers. The earliest version is that compiled by Gerald Gardner. This version, titled "Leviter Veslis" or "Lift Up the Veil", includes material paraphrased from works by Aleister Crowley, primarily from Liber AL (The Book of the Law, particularly from Ch 1, spoken by Nuit, the Star Goddess), and from Liber LXV (The Book of the Heart Girt with a Serpent) and from Crowley's essay "The Law of Liberty", thus linking modern Wicca to the cosmology and revelations of Thelema. It has been shown that Gerald Gardner's book collection included a copy of Crowley's The Blue Equinox (1919) which includes all of the Crowley quotations transferred by Gardner to the Charge of the Goddess.

There are also two versions written by Doreen Valiente in the mid-1950s, after her 1953 Wiccan initiation. The first was a poetic paraphrase which eliminated almost all the material derived from Leland and Crowley. The second was a prose version which is contained within the traditional Gardnerian Book of Shadows and more closely resembles Gardner's "Leviter Veslis" version of 1949.

Several different versions of a Wiccan Charge of the God have since been created to mirror and accompany the Charge of the Goddess.

Themes
The opening paragraph names a collection of goddesses, some derived from Greek or Roman mythology, others from Celtic or Arthurian legends, affirming a belief that these various figures represent a single Great Mother: "Listen to the words of the Great Mother, who was of old also called Artemis; Astarte; Diana; Melusine; Aphrodite; Cerridwen; Dana; Arianrhod; Isis; Bride; and by many other names."

This theme echoes the ancient Roman belief that the Goddess Isis was known by ten thousand names and also that the Goddess still worshipped today by Wiccans and other neopagans is known under many guises but is in fact one universal divinity.

The second paragraph is largely derived and paraphrased from the words that Aradia, the messianic daughter of Diana, speaks to her followers in Charles Godfrey Leland's 1899 book Aradia, or the Gospel of the Witches (London: David Nutt; various reprints). The third paragraph is largely written by Doreen Valiente, with a significant content of phrases loosely from The Book of the Law and The Book of the Heart Girt with the Serpent by Aleister Crowley.

The charge affirms that all acts of love and pleasure are sacred to the Goddess, e.g.:

"Let my worship be within the heart that rejoiceth, for behold: all acts of love and pleasure are my rituals. And therefore let there be beauty and strength, power and compassion, honour and humility, mirth and reverence within you."

Ancient precedents
In book eleven, chapter 47 of Apuleius's The Golden Ass, Isis delivers what Ceisiwr Serith calls "essentially a charge of a goddess". This is rather different from the modern version known in Wicca, though they have the same premise, that of the rules given by a great Mother Goddess to her faithful.

The Charge of the Goddess is also known under the title Leviter Veslis. This has been identified by the historian Ronald Hutton, cited in an article by Roger Dearnsley "The Influence of Aleister Crowley on Ye Bok of Ye Art Magical, as a piece of medieval ecclesiastical Latin used to mean "lifting the veil." However, Hutton's interpretation does not reflect the Latin grammar as it currently stands. It may represent Gardner's attempt to write Levetur Velis, which has the literal meaning of "Let the veil be lifted." This expression would, by coincidence or design, grammatically echo the famous fiat lux (Gen. 1:3) of the Latin Vulgate.

Origins
The earliest known Wiccan version is found in a document dating from the late 1940s, Gerald Gardner's ritual notebook titled Ye Bok of Ye Art Magical. The oldest identifiable source contained in this version is the final line, which is traceable to the 17th-century Centrum Naturae Concentratum of Alipili (or Ali Puli). This version also draws extensively from Charles Godfrey Leland's Aradia, or the Gospel of the Witches (1899) and other modern sources, particularly from the works of Aleister Crowley.

It is believed to have been compiled by Gerald Gardner or possibly another member of the New Forest coven. Gardner intended his version to be a theological statement justifying the Gardnerian sequence of initiations. Like the Charge found in Freemasonry, where the charge is a set of instructions read to a candidate standing in a temple, the Charge of the Goddess was intended to be read immediately before an initiation.

Valiente felt that the influence of Crowley on the Charge was too obvious, and she did not want "the Craft" (a common term for Wicca) associated with Crowley. Gardner invited her to rewrite the Charge. She proceeded to do so, her first version being into verse.

The initial verse version by Doreen Valiente consisted of eight verses, the second of which was:

Valiente was unhappy with this version, saying that "people seemed to have some difficulty with this, because of the various goddess-names which they found hard to pronounce", and so she rewrote it as a prose version, much of which differs from her initial version, and is more akin to Gardner's version. This prose version has since been modified and reproduced widely by other authors.

title: Charge of the Goddess