Topic: RoR v1 documentation

Hey there,

does anybody have any good documentation about Ruby on Rails v1. I have a project I need to support and it's written in RoR 1.2.3 and I have experience only with RoR 2.2 and RoR 3.

Can you suggest any painless way to update the app to RoR 3 or what is the best approach in this situation.

I appreciate any input, thanks in advance.