Like MHRD, but you wire the circuits by hand in your browser
MHRD is a hardware design game by Funghisoft, released on Steam in January 2017 for Windows, macOS and Linux. You write each design as text in the game's own hardware description language, inside a built-in development environment, working through more than 20 specifications such as a multiplexer, an adder, an ALU and RAM, and reusing your finished designs until you have a fully functional CPU. If that is what brought you here, digiwleea is a free, in-browser alternative with a different angle: you build a computer from the transistor up.
What MHRD is good at
MHRD's text-first approach is a real strength if you want to think like a hardware engineer: describing circuits in a hardware description language is how chips are designed in practice, and building each new design out of your own earlier ones mirrors real hardware work. (digiwleea is an independent project, not affiliated with Funghisoft.)
How digiwleea is different
digiwleea is free, runs in the browser, and is visual: you place transistors, gates and wires on a canvas and watch the signals settle live. You start from individual CMOS transistors, build the gates from them, and work up through adders, latches, registers, RAM and control logic to a working 8-bit CPU, with every part checked against its truth table, free theory lessons alongside and an AI tutor (Wleea) to explain a fault. When you want the text side too, the free Verilog and VHDL lessons describe the same circuits in code, and the lab can export a circuit as VHDL or build a combinational circuit from a short VHDL description. MHRD is the better pick if you want to practise writing an HDL from day one; digiwleea is the better pick if you want to see and wire every part first.
| MHRD | digiwleea | |
|---|---|---|
| How you design | Write text in the game's own HDL | Place parts and wires by hand |
| Runs in | A downloaded game (Windows, macOS, Linux) | The browser, nothing to install |
| Structure | 20+ specifications up to a CPU | 40+ level course + theory lessons |
| Industry HDLs | No (its own language) | Verilog and VHDL lessons, VHDL export |
| AI tutor | No | Yes (Wleea) |
| Price | Paid (Steam) | Free lab and Act I; Premium for the full course |
No sign-up is needed to start: open the lab and place your first transistor, or read the free theory course. The account (and the AI tutor) are optional.
See for yourself: build a logic gate from transistors in the simulator, then follow the path from sand to an 8-bit CPU.
Open the digiwleea lab →Frequently asked
Is digiwleea a good MHRD alternative?
Yes, if you want to understand digital logic from the ground up. digiwleea is a free, in-browser simulator with a guided 40+ level course where you build every gate from CMOS transistors and work up to a real 8-bit CPU, with an AI tutor to help.
Is digiwleea free?
The sandbox lab and the first act of the course are free and need no sign-up. An optional account adds the AI tutor and cross-device sync; the full course and expanded AI tutoring are included in the monthly or annual Premium subscription.
Do I need to install anything?
No. digiwleea runs entirely in your browser, on desktop or mobile, and works offline once loaded.