I am selling my house and would like to give the new homeowner instructions for my system (linked here). Is there an archive of documentation for older systems? Can someone tell me which hardware version I have by looking at the photo?
From the picture, it looks like you have OpenSprinkler 3.0 AC-powered. You can point them to the OpenSprinkler support website:
support.opensprinkler.com
which has videos, user manuals, and answers to common questions.