100 Generations CD-R Test - Page 1
February 15, 2004

I don't know if it's because I grew up in the analog era where copies of copies were always of poor quality, but I'm squeamish when I make copies of copies.  I remember the good ol' days when I would hook up 2 VCR's together and make copies of home movies or tv shows.  The copies were always really fuzzy and washed out, even when using premium quality tapes and good machines.  Today, with digital formats, I still get nervous about making copies of copies.  For example, when I get files from friends on CD-R's, I always ask if it's a 1st generation CD or if it's a copy of a copy.  (My friends have since learned to tell me that it's always a 1st generation copy even when it's not!)

The premise of this article is simple: To burn 100 generations of a CD and then compare the 100th generation copy with the original CD to see if the data is the same or if there are any differences.  Now, I don't mean making 100 copies of the same CD; that would be pointless.  I'm talking about making a copy of a copy of a copy, 100 times.  In other words, take a CD (original) then copy it making "gen 1".  Then copy "gen 1"  which gives you "gen 2".  Then copy "gen 2" which gives you "gen 3".   Do this until you get to "gen 100".  So you see, "gen 100" is a copy of "gen 99" which is a copy of "gen 98"...... all the way back to the original CD.  You get the point.

I know, I know, a copy of a CD with data on it should be exactly the same as the original.  But I can't help but feel nervous about the integrity of the data.  That's where I got the idea for this article.  Actually, I did this for my own peace of mind but thought that others might have the same concerns and would be interested in the results of some CD-R testing.