Learn
How a computer works, from one gate up
Every computer is a tower of small ideas stacked on one very small idea. These pages explain each layer in plain language, with diagrams you can click. The wiring itself is left for you to discover in the game.
- Logic basicsWhat is a NAND gate?A NAND gate outputs 0 only when all its inputs are 1. Its truth table, symbol, Boolean notation, why chips are built from it, and how it differs from NAND flash.
- Logic basicsLogic gates and their truth tablesThe seven basic logic gates (NOT, AND, OR, NAND, NOR, XOR, XNOR) with symbols, truth tables, Boolean notation, everyday examples and clickable demos.
- Logic basicsWhy NAND can build every other gateNAND is functionally complete: any logic circuit can be made from NAND gates alone. What that means, why AND, OR and XOR can’t do it alone, and how to prove it.
- ArithmeticHow a binary adder worksBinary addition column by column: what half adders and full adders do, how a ripple-carry adder chains them, why carries make adders slow, and what overflow means.
- ArithmeticTwo’s complement: how computers store negative numbersHow two’s complement represents negative numbers in binary, why the top bit is worth −128, how to convert by hand, the range of a byte, and why one adder can subtract.
- MemoryFlip-flops, latches and memory: how gates rememberHow feedback turns logic gates into memory: SR latch, D latch vs edge-triggered D flip-flop, registers, RAM, setup/hold time and metastability, with a demo.
- TimingThe clock: why computers tickWhy digital circuits need a clock: propagation delay, the critical path, how it sets the maximum clock speed, clock skew, and why GHz alone doesn’t decide CPU speed.
- The machineHow a CPU works, from logic gates upWhat is inside a processor: program counter, instruction decoder, registers, ALU and memory, and the fetch–decode–execute cycle, with a toy CPU you can single-step.
- The machineDesign your own instruction setWhat an instruction set architecture is and the choices behind one: opcodes, encodings, registers, addressing modes, RISC vs CISC, and how an assembler works.
- Where to startGames where you build a computer from logic gatesAn honest guide to games and courses about building computers from logic gates: nandgame, Turing Complete, nand2tetris, Digital Logic Sim, MHRD, Shenzhen I/O and more.