From bits to a real machine.
Hands-on lessons that build up the smallest useful model of a computer — starting from a single bit and ending with a working 8-bit CPU running real code. Click things, watch them change, build intuition. Friendly even if you've never written code.
Binary, by hand
5 lessons
- 01 Bits & bytes
Start with a single light. Add another, then another, until you have eight — a byte. Click your way to a feel for binary, no math required.
binary fundamentals - 02 Bigger words
Eight bits isn't always enough. Glue two bytes together — that's a word, sixteen bits, range 0 to 65,535. Plus what's actually moving on a real chip when those bits flip, and why a wider CPU gets more done per tick.
binary fundamentals words voltage - 03 Bit ops — AND, OR, XOR, NOT
Now we steer the wires. Four operations — AND, OR, XOR, NOT — are the workhorses of bit-level work. Each one has a real-world job that turns out to be the whole reason these operations exist.
binary bit-ops masks - 04 Overflow, underflow, and negative numbers
A byte can't go past 255 or below 0 — but it doesn't crash, it wraps. That same wrap is the key to a clever trick called two's complement that lets a single byte represent negative numbers, with a quirky asymmetric range that's worth understanding.
binary overflow signed twos-complement - 05 Arithmetic and shifts
Add and subtract walked bit-by-bit with carries. Why multiply costs more than add. And the two operations that are almost free — shift left doubles, shift right halves, just by sliding the wires.
binary arithmetic shifts add