How to format Powerbook 1400?

I have a powerbook 1400cs with only a floppy drive. I am new to Mac computers. I only have floppys built for Windows PC's. I would like to sell this laptop but I either need to format the hard drive (use a utility to permanently erase everything) or just erase all personal info off the drive (permanently). I don't know how to do either of these.

If I format the drive, I have no way to put an operation system on it.

Also if I could get a pdf manual of OS 8.1, that could help.

Specs:

Mac OS 8.1
117MHz CPU PowerPC 603e
Built in memory - 28mb
RAM doubled to 56mb
Machine ID - 310

this may be of some help

http://www.info.apple.com/usen/legacy/

"PowerBook 1400 Manuals"

http://docs.info.apple.com/article.html?artnum=50593

You might want to check out this page on Apple's Support site:

Macintosh: Support for earlier operating systems

This might help as well:

AppleCare Support - Older Software Downloads

OK, thanks