DeepHack

DeepHack: Spelunking for the 21st Century

QEMU

QEMU is a generic and open source machine emulator and virtualizer.

QEMU Secret Motor uses QEMU to create visualizations like this.

• More oscilloscope fun

The Elements of Computing Systems

• The book
• The synopsis
• The software

MMIX

MMIX is a 64-bit RISC machine used in Volume 4A of Donald Knuth's Art of Computer Programming and it will eventually be used in all other volumes of that series.

Open Computation Hardware

The OR1200 is an open-source synthesizable CPU.

What Every Programmer Should Know about Computer Memory

7-part series by Ulrich Drepper.