How Computers Work

Grandma Ruth’s laptop takes four minutes to start. Everyone says it’s junk. It isn’t. This is a course on how computers actually work: the processor, memory, the drive, the graphics chip, the operating system and the internet, five minutes at a time. By the end you can figure out why a computer is slow, and usually fix it. Four friends, Mark, Rob, Jenny and Sarah, take Grandma’s old laptop apart and put it back together over 24 modules. You learn each part by watching them work out what it does, and then trying it yourself. WHAT’S INSIDE • 24 modules, 96 five-minute lessons, in seven parts • Something to play with in every lesson: step a processor through its instructions, type real commands into a pretend terminal, wire logic gates, add in binary, route packets around a broken router, crack a cipher, mix pixel colours, diagnose a slow laptop from its Task Manager • A true story in every module, from the punched-card loom to ENIAC, the first hard drive and the first website • A Fix-It Card at the end of every module: one page for the day it happens at your house, like a slow computer, Wi-Fi with no internet, or a scam email • A Talk Card from every lesson: one sentence you could say to anyone WHAT YOU’LL LEARN Binary, bits and bytes. Logic gates. How a processor does math and makes decisions. Clock speed and cores. RAM vs. storage. Hard drives and SSDs. GPUs and why AI runs on them. Screens and pixels. Motherboards, ports and drivers. What happens when you press the power button. Operating systems and apps. Files, folders and backups. Mac vs. Windows vs. Linux. Routers, modems and IP addresses. Packets, DNS and undersea cables. How the web works. Passwords, two-factor and phishing. And when to fix, switch or replace an old computer. BUILT FOR Teens who want to know what’s inside the box, and anyone who’s ever been handed a slow laptop and told to “just fix it.” No experience assumed. FREE TO START Part I, the first three modules, is free, and so is the slow-computer lesson. One purchase unlocks the rest. NO ACCOUNT, NO ADS, NO TRACKING The app works offline. There’s nothing to sign into, no email, no password. Progress, cards and settings stay on the phone. There are no analytics and no advertising of any kind. How Computers Work is a Pettigrew Lab project, from the family that makes Data to AI and Product Management.