"The birth of a Paradroid" - Paradroid development journal for the C64 by Andrew Braybrook: http://www.zzap64.co.uk/zzap3/para_birth01.html
"Mental Procreation" - Morpheus development journal for the C64 by Andrew Braybrook: http://www.zzap64.co.uk/zzap23/mental1.html
"It's behind you" - R-Type Arcade conversion for the ZX Spectrum, free e-book by Bob Pape: http://bizzley.com/
Free sample pages of the development journals for Prince of Persia and Karateka by Jordan Mechner: http://www.jordanmechner.com/backstage/journals/
Prince of Persia code analysis after it got open-sourced in 2012; by Fabien Sanglard: http://fabiensanglard.net/prince_of_persia/
Analysis of Pacman; long after the fact: http://home.comcast.net/~jpittman2/pacman/pacmandossier.html
Any other? I'm sure there must be many nowadays...
Edit: Here it is (in 10 parts): http://popc64.blogspot.fr/2011/10/part-one-why-hell-would-an...
You would probably enjoy the book Racing the Beam http://mitpress.mit.edu/books/racing-beam
For a collection of (mostly consumer-oriented) behind-the-scenes material, check out http://www.reddit.com/r/TheMakingOfGames/
Or, if you want to get really technical http://handmadehero.org/
It's pretty intense. You don't even have proper sprites. they had to work with 8x8 pixel tiles and piece them together to create images. There were also pretty severe pallet limitations.
All in all it's very interesting.
I've always wondered what the process was for game programmers on the early PCs and consoles.
Are there any books or documentaries that go into depth about the development process of, for instance, Super Mario Bros? I've only seen stuff targeting "mainstream" audiences that glosses over anything technical.