NWA-PCUG Newsletter Article
A Gigantic Floppy or A Slow Hard Drive.
by John R. Clark, Webmaster, April 2000
(click to email author)

My large collection of 5.25" floppy disks is degrading fast. Disks created in the early 1980s are becomming quite hard to read. If I were to save this "valuable" data it was apparent that I would have to do something.

For the last few months I have been examining the technology of CDRWs, the CDs you read and rewrite up to 1000 times if you believe the advertisements. Actually I only plan to rewrite about two or three times. The read/write capability is due to a material that coats the disk. This material is the same as used on DVD-RAM disks and is usually made of a mix of silver, indium, antimony, and tellurium placed as a rigid polycrystallin coating on the disk. This mixture can be changed from a crystalline to an amorphous phase by temperature. If zapped by an infrared laser in the range from 900 to 1300 degrees F the crystals will melt, but if hit with a beam of 400 degrees F the crystals will reform. Hence all you need is a CD drive with a controllable laser. The main difference between the CDRW and a DVD is the laser of a DVD- RAM is a red laser and can write smaller spots.

The drive I have is an HP which comes with Adaptec software that allows me to format the CDRW as we use to format floppies back in the good old days. It took time to format the 2 Mbyte floppies, and it takes a lot more to format a 680 Mbyte CDRW. Recall the 3.5" 2 Mbyte floppy yielded about 1.44 Mbyte of usable space. A 650 Mbyte CDRW will yield about 561 Mbytes of usable space, a 700 Mbyte CDRW will yield about 598 Mbytes. This makes for a big "floppy", and you can work it as you would a disk in drive A. {There is some question if all CD drives will work on all of the 700 Mbyte disks.}

I see this system to have a cost benefit over a zip drive. The blank disks now are in the $1-2.50 range. This means for about 1/10 the cost you have 5 times the memory space that you would have with a zip drive and you don't have to worry about stray magnetic fields. That is a lot of memory for the buck.

When you purchase blank disks in the $1 range they sometimes do not have anything printed on them. Hence you must remember the write surface is light greenish in color while the CDRs are light blue. I obtained a 10 pack from MEI of Ohio for $9.70 and they were placed in their jewel cases upside down. However they all formatted and are working.

However since the write speed is about 300Kbytes/second and the read speed is about 480Kbytes/second the little disk can appear to be a slow hard drive. I have been known to install software on these CDRWs and thereby keep a lot of stuff off my harddrive. Like wise I have place installed subdirectories on my CDRW which should make rebuilding after a hardrive crash much easier. Also there is software that can make most modern regular CD readers capable of reading but not writing these CDRW disks. This means you can move information from one computer to another.

Click here to return to top