ROM - Wikipedia, the free encyclopedia. CD- ROMMedia type. Optical disc. Capacity. Mi. B (8 cm), 6. 50–9. Mi. B (1. 2 cm)Read mechanism.
A CD-ROM / ˌ s iː ˌ d iː ˈ r ɒ m / is a pre-pressed optical compact disc which contains data. The name is an acronym which stands for 'Compact Disc. No. unless you have some very special discs, you can only copy on one side of blank, writable discs. A lot of the inexpensive media will not have any.
Ki. B/s (1×), 1. Ki. B/s (7. 2×)Write mechanism. Ki. B/s (1×), 8,4. Ki. B/s (5. 6×)Standard. ISO/IEC 1. 01. 49[1]Usage.
Data storage. Optical discs. Optical media types. Compact Disc (CD): CD- DA, CD- ROM, CD- R, CD- RW, 5. Music Disc, Super Audio CD (SACD), Photo CD, CD Video (CDV), Video CD (VCD), Super Video CD (SVCD), CD+G, CD- Text, CD- ROM XA, CD- i.
DVD: DVD- R, DVD+R, DVD- R DL, DVD+R DL, DVD- R DS, DVD+R DS, DVD- RW, DVD+RW, DVD- RAM, DVD- D, DVD- A, HVD, Eco. Disc. Blu- ray Disc (BD): BD- R & BD- REUniversal Media Disc (UMD)Enhanced Versatile Disc (EVD)Forward Versatile Disc (FVD)Holographic Versatile Disc (HVD)China Blue High- definition Disc (CBHD)HD DVD: HD DVD- R, HD DVD- RW, HD DVD- RAMHigh definition Versatile Multilayer Disc (HD VMD)VCDHDGD- ROMMini. Disc: MD, Hi- MDLaserdisc: LD, LD- ROMVideo Single Disc (VSD)Ultra Density Optical (UDO)Stacked Volumetric Optical Disk (SVOD)Five dimensional disc (5.
D DVD)Nintendo optical disc (NOD)Archival Disc. A CD- ROM is a pre- pressed optical compact disc which contains data. The name is an acronym which stands for "Compact Disc Read- Only Memory". Computers can read CD- ROMs, but cannot write to CD- ROMs which are not writable or erasable. Until the mid- 2. CD- ROMs were popularly used to distribute software for computers and video game consoles.
There are various reasons why a CD or DVD drive is not detected. The resolutions that are listed in this article may help solve some instances but not all. CD/DVD drive not reading any discs.For the past 20 days i am having this new problem. If i click the DVD drive symbol,it says insert disc like there is no.
If your CD player, either a standalone audio CD player or the one built into your computer, has stopped reading CDs, a few issues could be causing this.
Some CDs, called enhanced CDs, hold both computer data and audio with the latter capable of being played on a CD player, while data (such as software or digital video) is only usable on a computer (such as ISO 9. PC CD- ROMs). The Yellow Book is the technical standard that defines the format of CD- ROMs. One of a set of color- bound books that contain the technical specifications for all CD formats, the Yellow Book, created by Sony and Philips in 1. Compact Disc Digital Audio. It adapted the format to hold any form of digital data.
CD- ROM discs[edit]. A CD- ROM in the tray of a partially open CD- ROM drive. CD- ROMs are identical in appearance to audio CDs, and data are stored and retrieved in a very similar manner (only differing from audio CDs in the standards used to store the data). Discs are made from a 1.
The most common size of CD- ROM is 1. Mini CD standard with an 8. Data are stored on the disc as a series of microscopic indentations. A laser is shone onto the reflective surface of the disc to read the pattern of pits and lands ("pits", with the gaps between them referred to as "lands"). Because the depth of the pits is approximately one- quarter to one- sixth of the wavelength of the laser light used to read the disc, the reflected beam's phase is shifted in relation to the incoming beam, causing destructive interference and reducing the reflected beam's intensity. This pattern of changing intensity of the reflected beam is converted into binary data. Standard[edit]Several formats are used for data stored on compact discs, known as the Rainbow Books.
The Yellow Book, published in 1. CD- ROMs, standardized in 1.
ISO/IEC 1. 01. 49 / ECMA- 1. The CD- ROM standard builds on top of the original Red Book. CD- DA standard for CD audio. Other standards, such as the White Book for Video CDs, further define formats based on the CD- ROM specifications.
The Yellow Book itself is not freely available, but the standards with the corresponding content can be downloaded for free from ISO[1] or ECMA.[4]There are several separate standards that define how to structure data files on a CD- ROM. ISO 9. 66. 0 defines the standard file system for a CD- ROM.
ISO 1. 34. 90 is an improvement on this standard which adds support for non- sequential write- once and re- writeable discs such as CD- R and CD- RW, as well as multiple sessions. The ISO 1. 33. 46 standard was designed to address most of the shortcomings of ISO 9. UDF format, which was adopted for DVDs. The bootable CD specification, to make a CD emulate a hard disk or floppy disk, is called El Torito. CD- ROM format[edit]Data stored on CD- ROMs follows the standard CD data encoding techniques described in the Red Book specification (originally defined for audio CD only). This includes cross- interleaved Reed–Solomon coding (CIRC), eight- to- fourteen modulation (EFM), and the use of pits and lands for coding the bits into the physical surface of the CD.
The structures used to group data on a CD- ROM are also derived from the Red Book. Like audio CDs (CD- DA), a CD- ROM sector contains 2,3. Unlike audio CDs, the data stored in these sectors corresponds to any type of digital data, not audio samples encoded according to the audio CD specification. To structure, address and protect this data, the CD- ROM standard further defines two sector modes, Mode 1 and Mode 2, which describe two different layouts for the data inside a sector.[2] A track (a group of sectors) inside a CD- ROM only contains sectors in the same mode, but if multiple tracks are present in a CD- ROM, each track can have its sectors in a different mode from the rest of the tracks. They can also coexist with audio CD tracks as well, which is the case of mixed mode CDs. Both Mode 1 and 2 sectors use the first 1.
Unlike an audio CD, a CD- ROM cannot rely on error concealment by interpolation; a higher reliability of the retrieved data is required. To achieve improved error correction and detection, Mode 1, used mostly for digital data, adds a 3. CRC) code for error detection, and a third layer of Reed–Solomon error correction[6] using a Reed- Solomon Product- like Code (RSPC). Mode 1 therefore contains 2. Mode 2, which is more appropriate for image or video data (where perfect reliability may be a little bit less important), contains no additional error detection or correction bytes, having therefore 2,3.
Note that both modes, like audio CDs, still benefit from the lower layers of error correction at the frame level.[7]Before being stored on a disc with the techniques described above, each CD- ROM sector is scrambled to prevent some problematic patterns from showing up.[4] These scrambled sectors then follow the same encoding process described in the Red Book in order to be finally stored on a CD. The following table shows a comparison of the structure of sectors in CD- DA and CD- ROMs: [4]Format↠2,3. CD digital audio: 2,3.
Digital audio)CD- ROM Mode 1: 1. Sync pattern)3 (Address)1 (Mode, 0x.
Data)4 (Error detection)8 (Reserved, zero)2. Error correction)CD- ROM Mode 2: 1. Sync pattern)3 (Address)1 (Mode, 0x. Data)The net byte rate of a Mode- 1 CD- ROM, based on comparison to CD- DA audio standards, is 4. Hz × 1. 6 bits/sample × 2 channels × 2,0. B/s = 1. 50 Ki. B/s.
This value, 1. 50 Ki. B/s, is defined as "1× speed".
Therefore, for Mode 1 CD- ROMs, a 1× CD- ROM drive reads 1. The playing time of a standard CD is 7. Therefore, the net capacity of a Mode- 1 CD- ROM is 6. MB or, equivalently, 6. Mi. B. For 8. 0 minute CDs, the capacity is 7. MB (7. 03 Mi. B). CD- ROM XA extension[edit]CD- ROM XA is an extension of the Yellow Book standard for CD- ROMs that combines compressed audio, video and computer data, allowing all to be accessed simultaneously.[8] It was intended as a bridge between CD- ROM and CD- i (Green Book) and was published by Sony and Philips in 1.
XA" stands for e. Xtended Architecture. CD- ROM XA defines two new sector layouts, called Mode 2 Form 1 and Mode 2 Form 2 (which are different from the original Mode 2). XA Mode 2 Form 1 is similar to the Mode 1 structure described above, and can interleave with XA Mode 2 Form 2 sectors; it is used for data. XA Mode 2 Form 2 has 2,3.
Mode 2 but with error detection bytes added (though no error correction). It can interleave with XA Mode 2 Form 1 sectors, and it is used for audio/video data.[7]Video CDs, Super Video CDs, Photo CDs, Enhanced Music CDs and CD- i use these sector modes.[9]The following table shows a comparison of the structure of sectors in CD- ROM XA modes: Format↠2,3. CD- ROM XA Mode 2, Form 1: 1. Sync pattern)3 (Address)1 (Mode)8 (Subheader)2,0. Data)4 (Error detection)2.
Error correction)CD- ROM XA Mode 2, Form 2: 1. Sync pattern)3 (Address)1 (Mode)8 (Subheader)2,3. Data)4 (Error detection)Disc images[edit]When a disc image of a CD- ROM is created, this can be done in either "raw" mode (extracting 2,3. CD- ROM mode). The file size of a disc image created in raw mode is always a multiple of 2,3. Disc image formats that store raw CD- ROM sectors include CCD/IMG, CUE/BIN, and MDS/MDF.
The size of a disc image created from the data in the sectors will depend on the type of sectors it is using. For example, if a CD- ROM mode 1 image is created by extracting only each sector's data, its size will be a multiple of 2,0. ISO disc images. On a 7. CD- R, it is possible to fit larger disc images using raw mode, up to 3. Mi. B). This is the upper limit for raw images created on a 7. Mi. B Red Book CD. The 1. 4. 8% increase is due to the discarding of error correction data.
Manufacture[edit]Pre- pressed CD- ROMs are mass- produced by a process of stamping where a glass master disc is created and used to make "stampers", which are in turn used to manufacture multiple copies of the final disc with the pits already present. Recordable (CD- R) and rewritable (CD- RW) discs are manufactured by a different method, whereby the data are recorded on them by a laser changing the properties of a dye or phase transition material in a process that is often referred to as "burning". Capacity[edit]. A CD- ROM can easily store the entirety of a paper encyclopedia's words and images, plus audio & video clips. CD- ROM capacities are normally expressed with binary prefixes, subtracting the space used for error correction data.
A standard 1. 20 mm, 7. MB CD- ROM can actually hold about 7. MB (7. 03 Mi. B) of data with error correction (or 8. MB total). In comparison, a single- layer DVD- ROM can hold 4. GB of error- protected data, more than 6 CD- ROMs.
Capacities of Compact Disc types (9. Type. Sectors. Data max.
Read this for CD/DVD Drive with burning, missing drives, not.. HP Support Forum. Seeing lots of the same posts with the same solutions being applied (mostly upper/lower control filters/MS Fixit)..
I thought I'd put this up for everyone.*Update* If this helps, please click the kudos to the right as I'm trying to gauge how effective this is. If you have the time to help the community, please reply stating what did or did not work. There are some helpful HP support articles that you may want to try before posting: If your drive cannot burn discs.. CDs but not DVDs (or vise/versa).. Drive Cannot Write to Writable Discs (Windows 7)Drive Cannot Write to Writable Discs (Windows Vista)Drive Cannot Write to Writable Discs (Windows 9.
ME, XP)Summary: 1) Try different discs! Cheap discs can be hit or miss. Find a disc brand and type that works best. Try burning at a slower speed (not the best option, but can often get the job done if the laser is fading). Remove drive from Device Manager and remove upper/lower filters (see below). Use MS System Restore to go back to a time when it was working. Use PC- Doctor/HP Hardware Diagnostic software to check for a bad drive.
If the drive is not bad - save your files and use HP Recovery to put the system back to the beginning. If your drive cannot read discs; CDs or DVDs or both.. Drive Cannot Read Discs in Windows 7. Drive Cannot Read Discs in Windows Vista. Drive Cannot Read Discs in Windows 9.
ME, and XP Summary: {restart the PC at least once to see if the drive shows up on boot}1) See if the drive is listed in Device Manager (look for problems if it is). Check autoplay (skip if you don't use). Make sure a bad disc isn't knocking out the drive (an operating system mounts discs as drives and things can get screwed up). Try reading the disc from a command prompt environment (outside of Windows).
Reinstall drive from Device Manager (if drive is listed). I'd replace this with bigger process of remove upper/lower filters (see below)}.
Use MS System Restore to go back to a time when it was working. Use PC- Doctor/HP Hardware Diagnostic software to check for a bad drive. CD/DVD drive is missing (not in Windows Explorer or My Computer or in burning software).. CD/DVD Drive is not Detected (Windows 7)CD/DVD Drive is not Detected (Windows Vista)CD or DVD Drive is not Detected (Windows 9. ME, or XP)Summary: 1) See if the drive is listed in Device Manager (troubleshoot based on what you see). Reset Power: Unplug power cord, press Power button for 1.
Check power and data cables attached to the drive and look in the BIOS for the drive name. Remove upper/lower filters (see below).
Reinstall burning software. Get and CD/DVD drive firmware updates if available (to prevent missing drives in the future (I assume)).
Use MS System Restore to go back to a time when it was working. Stuck Drawer.. Opening a Stuck CD or DVD Drive Tray. Summary: 1) Press eject button on case, on drive, button on keyboard (if exists). Right- click drive icon in Windows and select Eject. Turn off PC and inert a straightened paper clip into the manual release hole on the drive.
Check the power cord on the back of the drive. MS FIXit, Resetting Upper and lower Filters (XP, Vista and 7)First..
MS Fixit (for Vista) if you are on the computer having the problem).. Microsoft Fix it Solution. Otherwise, here are the manual steps (overview): 1) Uninstall the CD/DVD drive in Device Manager and DO NOT RESTART the computer. 2) Uninstall your CD burning software (make sure you have the installation disc or you can resinstall from Start, Programs, PC Help and Tools, Recovery Manager (or Driver/Application Recovery). If you don't have the installation discs, skip this step - it might still work).
Open the registry editor (Start - > Run - > enter Regedit) .. Open the following keys: + HKEY_LOCAL_MACHINE+ SYSTEM+ Current. Control. Set (or the current control set with lowest number if that is all that is listed)+ Control+ Class. Select 4. D3. 6E9. E3. 25- 1. 1CE- BFC1- 0. BE1. 03. 18. It has to be this exact key - make sure you can see the last numbers!!!
Delete the Upper. Filter and or the Lower. Filters value in the right window if either exists. RESTART the computer - this step is important. Wait for Windows to find and install the CD/DVD drive you removed earlier. Reinstall your burning software and restart the computer again. Message Edited by Garen.
T on 1. 0- 0. 7- 2. PMMessage Edited by Raster. Blaster on 1. 1- 3. PM. .. an HP employee expressing his own opinion. Please post rather than send me a Message.
It's good for the community and I might not be able to get back quickly.