Lesson 01

The World Computer

Understanding Virtual Machines, Global State, and the architecture of the Ethereum Virtual Machine (EVM).

The EVM

A distributed state machine that executes arbitrary code across thousands of nodes.

Global State

A single truth maintained by consensus, updated via atomic transactions.

Smart Contracts

Immutable logic that defines how the state can be modified by users.

How State Changes

State (S)

Old Ledger

apply(S, T) → S'

Validation &
Consensus

State (S')

New Ledger

// The Vending Machine Analogy
Initial State: Balance $0, 10 sodas
Transaction: Insert $2, select soda
New State: Balance $2, 9 sodas

The EVM Architecture

Stack-based Machine

LIFO structure for processing opcodes. Most operations happen here (size: 1024 items).

Memory (Ephemeral)

Linear byte-array, cleared between function calls. Costs gas to expand.

Storage (Persistent)

Permanent key-value store mapping 256-bit keys to 256-bit values. Very expensive.

Smart Contract Bytecode

EVM Interpreter

Stack

Memory

Storage

Hello World Contract

HelloWorld.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract HelloWorld {
    // State variable (stored in Storage)
    string public message;

    constructor(string memory _init) {
        message = _init;
    }

    function update(string memory _msg) public {
        message = _msg;
    }
}

Pragma

Tells the compiler which version of Solidity to use.

State Variable

Stored permanently on the blockchain. Notice the "public" keyword creates a getter.

Memory Keyword

Strings must specify location. 'memory' means it's temporary during the call.

Decentralized Logic and Smart Contracts

Introduction to Virtual Machines and State

Solidity Fundamentals and Modifiers

Gas Costs and Optimization

Token Standards and Composability

Deployment and Event Logging

EVM Architecture Slides

Hello World Lab Worksheet

EVM Fundamentals Teacher Guide

Access Control Slides

Secure Voting Coding Activity

Logic and Modifiers Answer Key

Gas Optimization Slides

Gas Hunter Worksheet

Storage vs Memory Cheat Sheet

Token Standards Slides

Money Legos Project Guide

ERC Interface Reference

Testnet Deployment Checklist

Event Logging Lab Guide

Deployment Pipeline Slides

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