Alternatives
Products that do what Codex builds a working NES Emulator in one hour does
Hi folks! I know NES emulators have been implemented countless times, in practically every language imaginable. However, having an LLM fully replicate the spec purely from memory—without referencing existing code—is still a significant challenge. It requires the underlying model to have strong anti-hallucination capabilities and solid long-term planning to keep from going astray. Because of this, building an NES emulator makes for an excellent LLM stress test. Here is how the emulator was built: Data Gathering: I asked Codex to download the necessary developer manuals and test suites. It was…
- 1MS
Finally got my hobby OS up and running on real hardware. I love the old IBM thinkpads, so thought it was the perfect machine to get it working on. Been working on it for quite some time now, but this has been a big milestone!
2025 · github.com
- 2IB
A while back I wrote a CHIP-8 emulator (which is considered the Hello, World! of emulators and is more accurately a virtual machine since historically CHIP-8 was an interpreted language running on top of the COSMAC VIP to make game programming easier). But a few months ago I got really interested in embedded software, so decided it would be neat to port my emulator to a STM32 MCU and design a console around it as a learning experience, since CHIP-8 never existed as a physical system. I didn't know much about embedded software when I began, and even less about electronics, but I managed to…
2022 · github.com
- 3GP
I've been exploring new ways of testing Ghidra processor modules. In this repo, I was able to emulate NES ROMs in Ghidra to test its 6502 specification, which resulted in finding and fixing some bugs. Context: Ghidra is used for reverse engineering binary executables, complementing the usual disassembly view with function decompilation. Each supported architecture has a SLEIGH specification, which provides semantics for parsing and emulating instructions, not unlike the dispatch handlers you would find in interpreters written for console emulators. Emulator devs have long had extensive test…
2023 · github.com
- 4AN
2013 · github.com
- 5AC
It's based on the jediterm library developed for IDEs, but it can also be put to work as a standalone terminal emulator with tabs. The library has been around for more than 10 years, but I don't think anyone made a terminal emulator app from it?
2025 · github.com
- 6IB
The HN community may find the context of the prompts, organized by each turn in each session, the most useful. See the website/docs/prompts.md and session-X.md files. I also started exploring some workflows for the LLM to execute, organized in the website/docs/tasks/ folder. I found it pretty handy to have the LLM document our work as we went and simply embedded the static site into the executable, along with all the music and logic. The whole project took me about a day for the backend. The C++ controller itself took only a few turns. I enjoyed focusing on my son's…
2025 · github.com
- 7

- 8CA
2016 · github.com
- 9IA
Hey HN! Been working on this emulator on and off for the last couple years, and thought now would be a good time to try and show it off here. As far as unique features... I think this is the only online GameBoy emulator with support for save files? So there's your reason to exist, I guess. The WASM port was something I had in the back of my mind but I just kept putting it off because it seemed like it would've been a pain in the ass to implement, but all in all I think it took less than a week so that was a nice surprise!
2023 · nicolas-siplis.com
- 10IR
Recently, I managed to recover some of my earliest work from the ZX Spectrum era from an old audio cassette. It is a mini-game, that I created as a teen, called "Atomix," written in BASIC with a mix of Z80 assembly — some of which I coded myself, while other parts were disassembled from existing games. I put the game in an modern emulator and recorded a screencast. See the video in my linkedin post: https://www.linkedin.com/feed/update/urn:li:activity:7288665...
2025
- 11AN
2019 · github.com
- 12LP
Hey HN, My team is open-sourcing the inference stack and fined-tuned models we use to create LLM-powered NPCs: https://github.com/GigaxGames/gigax The generative agents paper [1] pioneered the idea of prompting LLMs to create autonomous NPCs. But existing implementations require multiple calls to an LLM to make the agent plan its day, chat with people, and interact with its environment [2]. Our approach allows NPCs to be stepped at runtime with a single pass on consumer-grade hardware, with reasonable latency. To achieve this, we've fine-tuned open-source LLMs [3] to…
2024 · github.com
- 13YA
This is my first Rust project which I got a bit carried away with. It was a great way to learn different parts of Rust and had jump some hurdles when building for WASM, like not having access to loops, std or DateTime. I'd appreciate any feedback of improvements, new features or themes to add. Thanks! Github: https://github.com/hseager/you-are-merlin
2024 · hseager.github.io
- 14DM
I don't normally share side projects here(or in general). Don't have much time to open them up to too much attention. I started this project while riding in a car last weekend. Mainly to explore OpenAI Codex. Using Github mobile I wrote the initial specifications into the readme, and using the ChatGPT iOS app, had Codex build a simple CLI based dungeon master. Switched back to Github for managing the PRs and back and forth for the whole car ride... It kinda got a little out of hand from there, and it's now a mix of AI(mostly AI) and myself making adjustments... The first version was entirely…
2025 · github.com
- 15AL
Hello all, a couple of moons ago I ported karpathy's llama2.c code to run inference on the TinyStories 260K & 15M checkpoints on the on the PS Vita with the ability to download/delete the models on device. Runs showed that the 260K model ran at ~120 tok/s and at 15M ran at 1.8 tok/s, which probably could be a bit higher if it weren't a single threaded application. Had fun working on it as a weekend project, check it out for yourselves: https://github.com/callbacked/psvita-llm
2025 · github.com
- 162P
Hi HN! On Sunday I spent a couple of hours building a short 2d platformer ("Prince of Persia" style). What's interesting is how I built it. I went for a zero-code approach, and built the whole thing using OpenAI Codex CLI and agent skills (with the progressive disclosure paradigm). You can play the game here: https://acatovic.github.io/gothicvania-codex-demo/ You can see the full code, agent skills and a complete writeup here: https://github.com/acatovic/gothicvania-codex-demo Some takeaways: * This was one of the most enjoyable experiences ever! *…
Feb 2026
- 17IB
VSCode extension with games (Snake, Plinko, slots), HN/LessWrong reader, and Pomodoro timer for AI coding wait times. Fake currency only. Marketplace: https://marketplace.visualstudio.com/items?itemName=TouchGra... Built in a week with Claude Code after seeing Chad IDE get ratio'd for integrating real gambling. Happy to answer questions or get roasted on the code.
Dec 2025 · github.com
- 18IM
2012 · github.com
- 19RA
Hi there, looking for feedback on my new project "Featherless.AI" The idea is to allow users to run all the models on hugging face instantly. Via the OpenAI API compatible endpoint. Why? Because its a real chore to download models and spin up GPUs, especially if you want to test multiple models. Not to mention GPUs cost multiple dollars an hour to rent. And if we want more people to use open source AI, we got to make it easier for them to try and play with all of them. So what if instead of spinning up dedicated GPUs per model (which is what every provider is doing) We can startup a LLM…
2024 · featherless.ai
- 20PU
After seeing a cool demo of a hack on Twitter, I built a cross platform version of it that works well and uses streaming. From anywhere on Mac and Linux, trigger Ollama and optionally feed it your clipboard. I built it yesterday and it's already very useful to me. I'm pretty excited about it and wanted to share!
2024 · github.com
- 21EL
Hey HN! I built Experiment to solve a common frustration in LLM development: the lack of proper tools for prompt engineering experimentation. Here's what makes it different: Key Features: - Load and edit chat completion logs from CSV files - Fork and modify specific conversation entries - Run inference via Anthropic, Mistral, and OpenAI - Define custom tools using JSONSchema format - Visual tool usage analysis with collapsible, sorted key-value pairs - Full mobile support and available as installable PWA Technical Highlights: - Built with React using custom isomorphic architecture -…
2025 · github.com
- 22PR
MicroPython (lexer, compiler and VM) on the SNES: 3.58 MHz 65816, 56 KB Python heap, 16-bit int. The REPL runs right inside the post via EmulatorJS and also works on real hardware via flashcart. I did this as a benchmark for Claude Fable. When the export ban hit, switching to Opus got the project stuck for three weeks; Fable came back and found the real bug in ninety minutes. Along the way: 23 compiler bugs and 4 MicroPython bugs, each root-caused with a minimal reproducer and filed upstream. If you run it on real hardware, I want a picture!
Jul 2026 · fabian-kuebler.com
- 23RL
I recently created this project to teach assembly, and to have an assembly playground in the style of codepen/jsfiddle to embed in my blog posts. It's based on a wasm version of the blink x86-64 emulator, so everything runs client side with no backend server and with a runtime of only ~200Kb
2024 · x64.halb.it
- 24SS
Hola HN! Long time lurker, sometimes commentor, first time poster here. I’ve been working alongside my two co-founders and a few colleagues on a project I’m excited (and a little nervous) to share with you all! Like many of us, I’ve lived a tortured existence with AI coding (is it vibes?) over the past few months - I think November was a big moment with this. But, one thing I’ve noticed after building orchestration layer after orchestration layer is that the thing I always came back to was “what the hell is Claude Code actually doing?” Perhaps it’s because of the time Claude Code got…
Jun 2026 · backplanes.com
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