At the lowest level, everything starts with the transistor, acting as a tiny electronic switch. Logic gates are the primary building blocks created from these transistors. Fundamental Gates: AND, OR, and NOT. The journey from a simple electrical switch to

4. How to find these PDFs legally

• Search: "nand2tetris book pdf" → first link is often the official PDF of chapters 1–9.
• Search: "Computer Organization and Design RISC-V free pdf" → official UC Berkeley / Elsevier preview.
• Search: "crafting interpreters pdf" → Robert Nystrom's free book (covers compilers & virtual machines).
• Use: Google Scholar, Library Genesis (for out-of-print technical books), or your university’s Springer/ACM access.

Title: From Sand to Software: A Holistic Journey through Logic Gates, Circuits, Processors, Compilers, and Computer Architecture

Author: Digital Foundations Initiative Date: April 2026 Abstract: This document serves as a comprehensive guide to understanding the entire stack of modern computing. Beginning with the physics of transistors, we ascend through logic gates, sequential and combinational circuits, the architecture of a central processing unit (CPU), the theory of computation, and finally, the role of compilers and high-level software. By the end, the reader will understand how a simple line of code physically manipulates silicon atoms. Chapter 4: The Processor (CPU) – The Brain

1. Combinational Logic Circuits: These circuits produce an output based on the current input values.
2. Sequential Logic Circuits: These circuits produce an output based on the current input values and the previous state of the circuit.