What is this
"Ershov Computer" is a browser-based engineering simulator where you build your own computer step by step from absolute zero. Starting with the simplest logic gates, you'll construct increasingly complex blocks: memory, flip-flops, an arithmetic-logic unit, and finally a full 8-bit processor that you'll program yourself in assembly. This game turns complex computer architecture into a visual puzzle, helping you forever lose your fear of the "black box" of computing. In the third part, you'll tackle Verilog — the industry-standard hardware description language used by real chip designers.
What's inside
Let there be light!
Source → receiver. Your first wire.
Negation
NOT gate from a single NAND.
Perfect pair
AND gate from NAND and NOT.
At least one
OR gate via De Morgan's laws.
Strict choice
Exclusive OR (XOR).
Half Adder
Sum (XOR) + Carry (AND).
Full Adder
A, B, CarryIn → Sum, CarryOut.
8-bit Adder
Cascade of 8 adders. Buses.
Crossroads
MUX: digital 2-to-1 switch.
Loopback
SR latch from NOR. Foundation of memory.
Smart memory
D flip-flop. Captures on clock edge.
Tangible Memory
8-bit register from 8 DFFs. LEDs show the byte.
Operation Selection
Multiplexer picks the result: ADD, AND, or OR.
Heart of Math
ALU: ADD, AND, OR, XOR, NOT, SHL, SHR.
System Pulse
Manual clock. The concept of Clock. Counter on LED8.
Program Counter
PC from register and ALU. Address sequencing.
Anatomy of a Decoder
Instruction → control signals.
FINALE: The Ershov Computer
Harvard processor. Build and program it!
What you'll learn
Step-by-step learning
47 levels take you from a simple wire through AND, OR, NOT gates, adders, flip-flops, registers, and an ALU to a fully working 8-bit processor. Each level unlocks new components.
Visual programming
No boring code at the start. Just an interactive canvas: drag elements, connect them, watch signals flow. Understanding comes through your hands — you literally see how every gate works.
Real architecture
You'll build a Harvard architecture processor — separate instruction and data memory, an ALU with 8 operations, general-purpose registers, a program counter. This is a simplified model of a real computer.
Text-based design
After visual circuits, you'll master structural Verilog — a text language for hardware description. Write code that describes gates, buses, and modules, just like real chip engineers do.
How it works
Build circuits from logic gates right in your browser. Drag components onto the canvas, connect them with wires, and see results instantly. The built-in checker compares your circuit against the truth table — you immediately see which bits match and which don't.
Advanced Level
A processor is just the beginning. ROM and RAM modules, data buses, instruction decoders, I/O ports — you'll master every mechanism that makes a real computing machine. The built-in assembler lets you program the architecture you built with your own hands, while new components unlock peripherals and games.
Verilog Language
Graphical circuits give way to the industry standard. A code editor with Verilog syntax highlighting lets you describe digital circuits — from a simple gate to a full processor. The RTL Viewer visualizes your circuit in real time, and multi-file projects with tabs enable hierarchical design, just like real engineers at Apple and AMD do.
Computer Architecture
The culmination of the engineering journey — designing a control unit, creating your own instruction set architecture (ISA), connecting peripherals via Memory-Mapped I/O, and assembling a complete computer. The final project exports as a ZIP archive for programming onto a Tang Nano 9K board — your processor comes to life in silicon. A step-by-step runner, virtual LEDs and switches, a ROM editor, and an RTL Viewer with drill-down make debugging visual and engineering-honest.
AI Tutor
An AI assistant lives in the right sidebar. It analyzes your circuit, finds errors, and asks guiding questions to help you figure things out on your own. If you're truly stuck — it will show you a step-by-step solution.
Game Economy
Complete levels successfully to earn the in-game currency — Transistors. Your engineer profile keeps a history of all your victories. But be careful: using the ready-made solution via hints will deduct transistors from your balance. An incentive to think for yourself!
Knowledge Library
You don't need to search for answers elsewhere. The Library has everything you need — from theory to practice:
- Level Guides — step-by-step walkthroughs for all 43 levels: from the first wire to Verilog engineering debug
- Component Guides — datasheets for 36+ elements with truth tables, pin descriptions, and usage examples
- Circuitry Articles — 28 articles on logic gates, processor architecture, assembly language, and more
- Interactive Demo Examples — live schematics of 9 gates: toggle inputs and watch outputs update in real time
For Teachers
Ready-to-use materials for integrating the Ershov Computer course into your curriculum.
Methodology Guide
Detailed teaching guide: course philosophy, hardware platform, debugging, CPU evolution final project.
Project Pitch
A concise pitch for school administration: course value, educational outcomes, career guidance.
Ershov Board
Technical specification for the lab board: components, pin mapping, silkscreen, Ershov Loader.
Frequently Asked Questions
What is Ershov Computer?
An interactive browser-based simulator where you build an 8-bit processor step by step — from a NAND gate to assembly programming. No downloads required.
Is it free? What do I need to install?
Completely free. It runs entirely in your browser — no installs, no registrations, no downloads. Just open the site and start.
Who is this for?
Students studying computer science, undergrads in technical fields, and anyone curious about how computers really work — from silicon to code.
How is it different from NandGame?
"Ershov Computer" starts with the classic trio of gates (AND, OR, NOT), not a single NAND. The simulator offers a realistic engineering experience: honest work with buses, address decoders, and Memory-Mapped I/O. Built-in textbook and datasheets let you learn circuitry without external sources.
Do I need to know programming?
No. The simulator is designed for complete beginners. You'll start with a simple wire and, by the end, write assembly programs for your own processor.
Who is this for
Students
Computer science in practice. Live circuits you can touch with your mouse instead of dry theory.
Undergraduates
The perfect companion for a computer architecture course. All key concepts from gates to pipelining.
Enthusiasts
For everyone who always wanted to understand how computers really work, from silicon to code.
This is a CPU. Design your own!