Marshall Adult Education




TECH TIP:   All About CDs, CD-Rs and CD-RWs

How’s your CD-IQ?  No – it’s not a new kind of CD – just wondering if you know these facts about CDs, CD-Rs and CD-RWs.


1.  There is no significant difference between Music CDs and Data CDs.  Music CDs were created for stand-alone audio CD recorders (which practically no one has).   But when used with CD burners on a computer, Music CDs and Data CDs are exactly the same.


2.  Music CDs are more expensive than Data CDs – don’t buy them (unless you have a stand-alone audio CD recorder – or unless you have money to burn).


3.  The difference between CD-R (CD Recordable and CD-RW (CD Re-writable) is that you can completely erase a CD-RW and start over.  You have to have a CD-RW burner to use CD-RWs.


4.  Be Careful!  If you burn music or data on a CD-RW, you may not be able to read the information on other computers.  You won’t be able to play the music on regular CD players like boom boxes, etc.


5.  It takes 20 minutes to an hour to erase a CD-RW, depending on the speed of your drive and the speed of the CD - that’s a pain.  I have a CD-RW burner – I rarely use it.  CD-Rs are so cheap – about 25 cents each, that I just use those.


6.  You can erase a CD-RW at least 1000 times - that’s the industry benchmark.  But some CD-RW manufacturers claim you can erase them 100,000 times. 


7.  Most CDs hold from 650 to 700 MB – that’s 74 to 80 minutes of music.  You can also buy mini-CD-Rs that hold around 200 MB (some hold a little more, some hold a little less).   These mini-CDs are a great way to transport files or music because the mini-CD fits in your shirt pocket (right behind your pocket protector). 



8.  What’s the best brand to buy?  Well, only a handful of companies actually make CD-Rs and CD-RWs.  These companies then put brand name labels on them, like Maxell, Sony, Fuji, Memorex, etc. Sometimes a certain brand doesn’t work very with some burners.  So find a brand that works well with your burner and stick with it.  I use Fuji CD-Rs – I very rarely burn a bad CD.  I don’t use Memorex – I have a large failure rate with those CD-Rs.  Your burner is probably different than mine.


9.  You can use a CD-R just like a floppy.  That means, you can copy files to it many times – until you fill it up – 700 MB.  So everyday, you can add files to the CD-R.  You need special software to do this.  Usually this software comes with your CD burner or your computer.  I use a program called Direct CD by Roxio.  You can also erase individual files on a CD-R, but you can’t use those sectors (tracks) from the erased files over again.


10.  Burned CD-Rs supposedly last from 75 years to 200 years according to the CD manufacturers.  CD-RWs don’t last quite that long – they lose some of their lifespan every time they are re-written.


11.  CDs are sturdy.  But you need to handle them carefully.  And, you need to protect both sides of the CD.  On the bottom side - the “read” side, don’t get fingerprints, smudge marks, or dust on it.  Also don’t allow it to get scratched.  Using a soft lint-free clothe or tissue, gently wipe the CD from the center toward the outer edge in a straight line.  Do not wipe in a circular motion.  You can also use water or even mild soap.  Gently dab dry it with a lint free soft clothe


12.  Handle the top side – the label side – of the CD carefully also.  If you scratch it, the scratch could penetrate the very thin top layer and destroy the data right under it.  Use only soft felt tip markers to label a CD.  A Sharpie pen works well.  Use only good quality paper CD labels if you want to label your CD in that manner.  Never peel a label off a CD – you will surely peel off the top layer and destroy some of the data just under it.


A really cool site to find out how stuff works is

You can find out how just about anything works at this site.


This is the link to “How CDs Work.”


And this is the link to How CD Burners Work.”


Here are 2 sites that have more information than you can ever imagine about CD-R technology.



Lyon County Government Center  •  607 W. Main St.  •  Marshall, MN 56258  •  (507) 537-7046

E-Mail:    Marshall Adult Education