RE: TOM BRETT'S DESIGNS-UPDATE
Duane,
We engineers keep a log book of EVERYTHING we do. Our employers need it in case of a patent (to show as early a date as possible, or to show "prior art" when contesting another's patent). I have TONS of code that will never be used, schematics, PCBs, everything. I have my log books from 20+ years ago, even stuff from before I graduated ... from high school! I use a log book every day as I encounter problems, writing down everything I can think of as a resolution, then check them off (and date them) for every item as I find it works or doesn't.
It's a very painful thing to throw that stuff away. I have boxes in my attic which mean nothing to anybody in my house, but they are log books, sketches, etc. When I moved out of my parents house, my mother cleaned up ("cleaned OUT" would be more accurate) a lot of my early airplane designs. What I wouldn't give to have them now!
It's silly, but I can tell you exactly what problem I was working on 20 years ago today. All I need to do is pull down a logbook off the shelf and flip to the right page.
Andy