The Cuneiform Tablets of 2015 by Long Tien Nguyen and Alan Kay
The Development of the C Language by Dennis Ritchie
Reflections on Trusting Trust by Ken Thompson
The Dutil-Dumas Message sent as part of Cosmic Call
Preventing the Collapse of Civilization by Jonathan Blow
Toybox vs BusyBox by Rob Landley (linked to 12:03 but the whole talk is worth watching)
A rant on personal engineering projects by Joe Barnard
bcompiler (.tar.gz) by Edmund Grimley Evans
stage0 by Jeremiah Orians
CC500: a tiny self-hosting C compiler by Edmund Grimley Evans
Writing a C compiler in 500 lines of Python by Theia Vogel
Primeval C compilers, NB, etc.
NandGame - Build a computer from scratch.
TempleOS by Terry Davis
Robert Elder's one page CPU and the RECC Compiler
The design of MessagePack by Sadayuki Furuhashi
The TOY machine from Sedgewick and Wayne
Ben Eater's 8-bit breadboard computer
Classic architectures like PDP-11 (designed to be programmed directly in octal)
And of course modern RISC ISAs like ARM and RISC-V
Primitive Technology by John Plant