CoreTrace, a visual 16-bit CPU simulator
I built a 16-bit CPU simulator that runs entirely in the browser. You can write assembly, run it, or step through it one instruction at a time while watching what happens inside the CPU. It shows the registers, memory, flags, ALU, buses, and datapath as the program executes. You can also set breakpoints, inspect execution cycles, replay previous cycles, and try some example programs. I built this because I wanted CPU architecture to feel more tangible. Reading about fetch, decode, registers, buses, and the ALU is one thing. Watching an instruction actually move through the CPU is much more…
What it does
CoreTrace is a free, browser-based 16-bit CPU simulator. Write assembly code, step through instructions, and watch the Control Unit, ALU, registers, and RAM animate in real time. Perfect for learning computer architecture, assembly language, and CPU design.
In the maker’s words, at launch
I built a 16-bit CPU simulator that runs entirely in the browser. You can write assembly, run it, or step through it one instruction at a time while watching what happens inside the CPU. It shows the registers, memory, flags, ALU, buses, and datapath as the program executes. You can also set breakpoints, inspect execution cycles, replay previous cycles, and try some example programs. I built this because I wanted CPU architecture to feel more tangible. Reading about fetch, decode, registers, buses, and the ALU is one thing. Watching an instruction actually move through the CPU is much more interesting. Try it here: https://coretrace.srianjaneyam.me/ This is my first Show HN, so I'd really appreciate feedback, especially from people interested in CPU architecture, emulators, or computer architecture education.
Does the same job
all alternatives →- 8B8-bit CPU simulator in C2020 · github.com · ▲67
- H3Homemade 32-bit CPU and OS (2015) [video]2016 · youtube.com · ▲253
- CSCPU simulator in 60 lines of code2015 · github.com · ▲60
- OCOnline challenge: Build a CPU from scratch2018 · nandgame.com · ▲143
- CACoDiff, a new collaboration tool for developers2019 · ▲26
A recent HackerNews comment - “For one programmer's hourly cost, you could run 4000 CPU cores continuously. Can there really be no practical way to apply thousands of cores to boosting the programmer's productivity?” https://news.ycombinator.com/item?id=19339467 This is what we have come up with. The current productivity tools - Slack, Asana, Trello, Facebook Workplace, etc. - are great, but lack direct access to your code. Building a tool directly around the code makes it more powerful for software developers: CoDiff. https://codiff.com The foundation of CoDiff is a…
More life & fun this month
the category →- TL
Life & fun · 10d ago · louisabraham.github.io
Photosynthesis fires two of your iPhone
Life & fun · 28d ago · photosynthesis.camera
SoloUno▲310Take control of hair pulling, nail biting & skin picking
Life & fun · 28d ago · solouno.io
Scroll through all 43,252,003,274,489,856,000 reachable Rubik's Cube permutations.
Life & fun · 26d ago · everycube.alen.is
Hi HN, I built Eigendrum, a web tool that solves the 2D wave equation for arbitrary shapes so you can hear what they sound like as drums. How it works: * Solves -∇²u = λu using finite element analysis (Kφ = λMφ) on a triangle mesh. * Validated to <0.1% error against closed-form solutions for circles (Bessel zeros) and rectangles. * Sound model factors in strike location, Rayleigh damping, and mallet width. * Includes Kac drums I & II to demonstrate identical sound spectra from different geometries. * No frameworks, build steps, or dependencies. Repo and tests:…
Life & fun · 26d ago · baselashraf81.github.io
Launched alongside, August 2026
the whole month →- TL
Life & fun · 10d ago · louisabraham.github.io
- SA
Hello HN! I found that picking out plausible but diverse skin tones for my digital art and game development projects was kind of difficult, and I got curious about if there was a way to define a color space that made it easy. I've built a color picker and procedural generation algorithm based on the space as well as a bunch of other fun js features and demos throughout the page that use the equations. If you find it interesting, I have lots of explanations of how I built it and what properties the space has. The methodology might be a bit shaky, but hopefully the result is as helpful for…
Life & fun · Aug 2026 · toneyalexander.github.io
I trained a 125M-parameter transformer to autocomplete piano performances in real time (~108 notes/sec on an iPhone 15). The idea is basically GitHub Copilot or Tabnine, except instead of prompting it with code, you prompt it by playing a few notes on a MIDI piano. The model then continues what you played, entirely on-device. The app is free if anyone wants to try it. Happy to answer questions about the model, training, Core ML, or the many things that didn't work.
AI · 17d ago · simedw.com