Opcodes vs Learning transistor

Opcodes – The Retro CPU Reference The definitive opcode reference for the legendary processors that launched the personal computer revolution. Whether you're a retrocomputing enthusiast, a student of computer history, writing code for classic hardware, or just a big old nerd - the Opcodes app gives you everything you need. Eighteen iconic processors covered: Intel 4004 · Intel 8008 · Intel 8080 · Intel 8085 · Intel 8088 · Zilog Z80 · Motorola 6800 · Intel 8085 · Motorola 6809 · MOS 6502 · Signetics 2650 · RCA 1802 - SC/MP · Motorola 68000 · Intel 8086 · WDC 65816 · Texas Instruments TMS9900 · INMOS Transputer · ARM2 For every opcode:  • Full description of what the instruction does. • Hex, octal, and decimal values. • Flags affected. • Addressing modes and cycle counts. • Assembly code examples - including loops, conditionals, and common patterns. More than just opcodes:  • CPU history and historical context. • IC pinout diagrams. • Notable systems that used each CPU, with memory maps and other background information. • Chip variants and successors. • A silly card game(!) • Simple assembler / disassembler for many CPUs. Built for exploration:  • Search for opcodes by name or category. • Sort by mnemonic, opcode byte, or category. • Filter by category, Quick Find with a colorful map. • Undocumented instructions clearly marked and optionally displayed. More than microprocessors:  • Information on key support chips: video, sound, memory and more. Cool design:  • Clean, readable layout optimised for quick reference. • Multiple colour themes. • Full "dark mode" support. Everything is included with absolutely no in-app purchase required. Recent additions: • Quiz game - test your CPU knowledge! • Share CPU cards - beautiful shareable images showing specs and history for any processor • External references - curated links to community resources for all 18 CPUs • "Opcodes display first" setting - choose whether selecting a CPU shows opcodes or info first • Chip-maker colour themes - Zilog, MOS Tech, and Motorola replace the old themes • Enhanced 6502 docs - JMP page boundary bug, BRK behaviour, and Read-Modify-Write quirks • Fixed Scratchpad hang when switching tabs

How does a computer actually compute? Not metaphorically — physically. Learning Transistor answers that question in 14 interactive screens, starting from a single transistor and ending at a working one-bit computer you can step through with your finger. Every screen is a live circuit. Current flows as moving dots, voltage glows on the wires, and every input is yours to flip. Nothing is a video, and nothing is a quiz — you learn by turning things on and off and watching what the electrons do. THE JOURNEY - Meet Transistor Man — the classic mental model of how a transistor keeps its collector current exactly 100 times the base current, and what happens when it can't - The transistor switch: how 9.4 mA of base current lights a 100 mA lamp - The NOT gate: how a resistor and a transistor turn voltage into logic — and why "1" costs no current at all - NAND and NOR at the transistor level: series vs parallel, and why these two gates can build everything else - The symbol language: the D-shape, the pointed shape, and the little circle that flips every answer - Building with gates: AND from NANDs — abstraction you can tap to open and see the transistors still working inside - The SR latch: two crossed gates that remember one bit after your finger leaves the screen - XOR and the half adder: the moment logic becomes arithmetic, and 1 + 1 becomes 10 - The finale: memory + adder + feedback + a STEP clock — a one-bit computer, with every layer tappable all the way down to the silicon FREE TO START The first two screens — Transistor Man and the transistor switch — are free. A single purchase unlocks the rest of the journey. No subscriptions, no ads, no accounts, no data collection. Inspired by the classic figures of The Art of Electronics. Made for curious minds who want to know what is really happening inside the machine they are holding.