The following is from the DSL Documentation.
"If your board is not capable of booting from CD-ROM (or USB), you will need to make a Boot floppy! Just head over to one of the mirrors and grab the latest boot- x.x.x.img (or boot-usb-x.x.x.img). It should be in the "current/" directory.
In linux, you can create a boot floppy by typing
***Code Sample***
dd if=boot-X.X.X.img of=/dev/fd0
***End Code Sample***
As far as windows, may I suggest John Newbigin's RawWrite for Windows. It's available at
http://uranus.it.swin.edu.au/~jn/linux/rawwrite.htm and is a lot easier to use than the original command-line based rawrite2.exe."
Hope this helps.