* [Computer Organization and Design Fundamentals](https://faculty.etsu.edu/tarnoff/138292) - David Tarnoff (PDF)
* [Digital Circuit Projects: An Overview of Digital Circuits Through Implementing Integrated Circuits - Second Edition](https://cupola.gettysburg.edu/cgi/viewcontent.cgi?article=1000&context=oer) - Charles W. Kann (PDF)
* [Dive Into Systems: A Gentle Introduction to Computer Systems](https://diveintosystems.org) - Suzanne J. Matthews, Tia Newhall, Kevin C. Webb (HTML)