Alternative source with multiple formats including an OCR'd text file: https://archive.org/details/furby-source
This is where it came from, in case anyone (including me) was wondering --- there are a handful of articles online claiming it was "leaked", but it doesn't appear to be so.
It is probably not coincidental that this marks the 20-year expiry of that patent.
Patents can have very interesting things in them, including source code. I can't find the reference now but I remember reading that a famous early calculator (TI? HP?) was reverse-engineered and emulated down to the transistor level because of the detailed chip layout and source code from a patent.
I proceeded to contact him and he proceeded to scan and publish it in a few days.