I have an old computer I finally want to get rid of and I need to destroy all the data on the drives before sending it to be recycled. There is a simple GPL solution called Darik's Boot and Nuke which does the trick. But the directions on the Website don't quite work for Mandrake 9.1. Here were the changes I had to make:
To copy the image to a floppy I had to use dd if=dban-*.img of=/dev/fd0.  I had trouble with /dev/random generating enough bits. The easiest workaround is to substitute /dev/urandom for /dev/random. But there is a more paranoid choice. 
 In most system apparently /dev/floppy points to the floppy device but in Mandrake 9.1 it points to a directory with the floppy's contents. /dev/fd0 is what Mandrake uses to point at the actual floppy image, it's a link to /dev/floppy/0.
 /dev/urandom uses a crypto grade hash to extend the amount of random data collected by /dev/random. This should be fine but I'm really paranoid so instead what I do is first run dd if=/dev/random of=MySeedFile bs=512 count=20. This will give me more than the 512 bytes required by DBAN. You will have to play with the mouse a bit to generate enough random data to fill the request. Once the dd returns then I execute dd if=MySeedFile of=MySeedFile2 bs=512 count=1 and then delete MySeedFile.