Does a super light, super cheap typing instrument exist?

I want to bring something backpacking with me on which to record my thoughts. I know, I know, there’s this thing called pen and paper, but I am so used to typing that those things don’t really work for me.

What I am looking for is something that is like a notebook/laptop, super cheap, super limited capabilities (i don’t even care if it can get internet) and light enough to carry around. I suppose I could get a used Acer or something, but figured I’d check first.