CD-R


Also found in: Dictionary, Thesaurus, Medical, Legal, Financial, Acronyms, Wikipedia.
Related to CD-R: DVD-R

CD-R

(communications)
A compact-disk format that allows users to record audio or other digital data in such a way that the recording is permanent (nonerasable) and may be read indefinitely. Derived from compact-disk recordable. Also known as compact-disk write-once (CD-WO).

CD-R

CD-R

(1) (Call Detail Reporting) See call accounting.

(2) (Common Data Rate) The standard 13.5 MHz sampling rate for 480i and 576i digital video systems. See ITU-R BT.601 and CIF.

(3) (Compact Disc-Recordable) A type of CD disc that can be recorded, but not erased. Introduced in 1988, a CD-R is used to back up and transfer data as well as master CD-ROMs. The discs can be written ("burned") and read by most CD/DVD drives. The phrase "burn a CD" really means "burn a CD-R."

Capacities
The most common CD-R formats hold 650MB (74 minutes) of data or 700MB (80 min.). Also available are 550MB (63 min.), 790MB (90 min.) and 870MB (99 min.), the latter two being non-standard. The higher capacities are achieved by reducing the distance between tracks (track pitch). To record a full 650MB disc takes only a couple minutes using 40x recorders. For speed ratings of drives, see CD-ROM drives.

Change the Reflectivity
The binary 0s and 1s in CDs and CD-ROMs are actual pits (or lack thereof called "lands") stamped into the media. CD-Rs create the equivalent of pits and lands by altering the reflectivity of a dye layer. Different dyes are used, including cyanine (green), pthalo-cyanine (yellow-gold) and metal-azo (blue). See CD-RW, multisession, disc-at-once, track-at-once, CD UDF and optical disc.


CD-R Layers
Fresh out of the box, a CD-R disc is entirely reflective, because the dye layer is transparent. In order to create the equivalent of a CD or CD-ROM pit, the laser deforms the dye, making it darker and less reflective. In contrast, CD and CD-ROM pits are molded into the plastic and covered by an aluminum reflective coating (for more details, see CD-ROM).







A Partially Burned Disc
Recording starts at the center and spirals outward. To tell if a CD-R was burned, look for the slight change in reflectivity on the recording side. In this example, only 6% of the disc has been written, and the arrows point to the end of the recorded area (look carefully).







Burning a CD-R
To "burn" a CD-R, the files are dragged and dropped into a recording window as in this Easy CD Creator example. Most software supports audio and data CDs and may also print the cover and inside jacket of the jewel case.
References in periodicals archive ?
4) Set the signal level of the CD-R to -20dB to ensure all but the craziest cut disks will not overload the analog-to-digital converter (ADC) of the CD-R recorder while still giving you 70dB of signal-to-noise (SNR) relative to the noise level of the ADC (we assume here the ADC has a worst case equivalent number of bits of 15 which is common for most CD-R recorders).
Make sure the test disc tone is recorded to the CD-R. As an option you can try to match the levels of the tone using the precision attenuator if you have individual ones for the left and right.
I found four minute cuts to be sufficient and wound up with about ten test recordings per CD-R.
The basic recording process for DVD-R discs should be familiar to any user of CD-R technology.
This differs from how track-at-once CD-R discs are typically written, where the data area is written first, followed by the lead-in/table of contents and lead Out areas.