Bitrot, according to Wikipedia, refers to “the decay of physical storage media.” Back in the early days of computing, losing data was a way of life. I’ve seen people in tears more than once after discovering the floppy disk that once held their homework was no longer readable. Floppy disks are magnetic storage media; as such, directly applying a magnet to a disk is a very quick and efficient way to scramble the contects of a disk. In fact, throughout the years many people have learned the hard way that the magnet fields found in computer monitors and stereo speakers are strong enough to damage floppies. I used to cringe each time I visited a fellow computer user’s home and spotted a pile of floppies stacked atop a computer monitor.
Bitrot, however, is a little different. Bitrot generally refers to the loss of data simply due to age. I struggle with bitrot every time I pull out one of my old Commodore 64 diskettes. Slowly but surely, those things are fading. Sometimes the data loss can be attributed to magnets, or temperature (both heat and cold affected floppies), or any number of given variables, but even the best cared for diskettes eventually give in. The magnetism inside a floppy simply won’t last forever.
(This is, by the way, the same technology used within hard drives.)
Another cause of bitrot, and the one I’ve been dealing with this week, is defective media. One of the most debated questions when it comes to CDs is, “how long will CDs last?” The real answer to that question is, “it depends on the media.” While I have many CDs that are approaching the 20 year mark, I recently had several fail. Most of the CDs I burned in 1995 and 1996 have begun “flaking.” Just as it sounds, the data layer of the CD has begun flaking off. These CDs have been stored in either a plastic CD jewel case of a vinyl binder their entire lives. They weren’t abused or dropped or scratched, they simply failed. Flaking isn’t the only type of CD bitrot I’ve experienced; I’ve also seen bronzing, a specific problem traced back to Phillips and Dupont CDs made between 1988 and 1993. The lacquer coating layer on these discs can chemically react when the discs come in contact with paper. Over time the silver layer turns a bronze color (thus the name) and the discs become unreadable. These CDs were used by over two-dozen recording companies, and most of these CDs have died. I have a couple of them in my personal collection.
A friend of mine recently asked if I had a couple of old games in my collection. I have spent a lot of time collecting, archiving, and documenting old programs. I proudly searched my database, found the old files, and pulled out my CD book to retrieve the files. When I pulled the CD out of its sleeve, I saw gold sparkles fall like snowflakes off the discs surface. Oh NO. Dead. Fortunately I had most of these old files backed up, but this CD turned out to be completely unreadable.
Quality DVDs right now are running .40 cents each; that’s $40 for 100, and with that you get 450 gig of storage. I just checked TigerDirect and right now you can get a 500 gig hard drive for $99. The two aren’t quite interchangable yet, but the gap is closing. I suspect there will be a day where hard drives are used as a primary backup storage device.
Over the weekend I copied around 50 CDs of old data to my laptop’s hard drive. My immediate goal for this project is to clean up, resort, and burn this data back on to DVDs rather than CDs. In the back of my mind though, I’m considering picking up another USB hard drive and using that instead of DVDs …