books

i've got holidays for the next couple months and i've got no social life or off-line friends to speak of.
what are some good text books i can read during this time?
any subject is fine really, as long as it's somehow related to computers.
and by 'good' i mean detailed and thorough, not fun to read.

I'm reading the ARM architecture reference manual this christmas. At least, I will if I can find a recent version.
Maybe I'll continue where I left off on the Dirac specification as well. It feels so great to have time to waste.
And don't forget the SHA3 submissions, there should be some good papers there.