Linux, Windows, OSes and Low Level stuff
TODOResources
Linux Insides
Great tutorial to dive into the Linux kernel process from the bootloader stage through paging, memory management, syscalls, interrupts, etchttps://0xax.gitbooks.io/linux-insides/content/
Nandgame
Build a whole computer starting from basic NAND gates through a series of levels of increasing complexity.https://www.nandgame.com/