Disassembling the Norton Utilities and annotating them was an excellent way to learn how to program X86, I'm not sure if by then Peter was still writing himself or too busy managing his growing empire but that was some pretty tight code. Think 'gnu base utils' but instead of in C a good chunk of it (if not all) was in assembler.

It's a pity the article does not really answer the question in the title, Peter is simply getting older (he's probably in his 70's now). Here he is at some function a few years ago, looking happy and well:

http://i558.photobucket.com/albums/ss23/Image-Gallery/norton...

I wish him a very long life and much joy, he's done a ton of good for the PC industry and his books on low level PC stuff were quite useful.