TabStationToo brings a PS2 emulator to your browser, mostly coded by Claude

What this is about

Two friends used Claude to bring the PlayStation 2 emulator PCSX2 to the browser. The project is called TabStationToo. You can reach it at tabstationtoo.github.io/TabStationToo, and the code is on GitHub. An emulator is a program that imitates a different console, so its games run on an ordinary computer. According to the developers (in a Reddit post by u/yousriii), you open the page, pick your BIOS and a folder with your own disc images, and start playing. It works best in Chrome. The authors say the project is early and experimental. It has no connection to Sony or the PCSX2 project, so bug reports should not be sent to PCSX2.

What you need and how it works

The project is free and open source. You need the BIOS from a PS2 you own (usually a 4 MB .bin file) and disc images of games you own. The BIOS is the console's firmware. The developers say all files stay on your machine and nothing is uploaded. The game is read directly from the image. Digital Trends recommends desktop Chrome or Edge as a starting point. Smartphones aren't supported yet. You can play with a keyboard or gamepad, and memory card saves and save states (saving your progress at the press of a button, for example F1 to save and F3 to load) are available. The page shows the key bindings, a log, a speed readout (VPS/FPS) and a recorder. Developers need the Cross-Origin-Opener-Policy and Cross-Origin-Embedder-Policy headers; for local use there is a script, tools/wasm/serve.py. Firefox users should set dom.gamepad.non_standard_events.enabled to true so fast gamepad button presses register.

How Claude helped

The developers say they decided what to build, tested games and reported bugs. Claude did most of the programming. They point to four things:

• A rulebook for Claude: The repository contains a CLAUDE.md/AGENTS.md that Claude reads at the start of every session. It explains the project, the browser's limits, the build and the tests. It also sets rules: credit PCSX2, and never claim something works without having tested it.
• Testing without the developers: Claude built a version of the emulator that runs without a browser. It boots the PS2 BIOS, runs benchmarks, renders a few hundred frames after every change and takes its own screenshot.
• The hard parts: On a PC, PCSX2 is fast because it translates PS2 code into native machine code at runtime (JIT). Browsers don't allow that. Instead, the developers and Claude wrote a replacement that translates PS2 code into WebAssembly at runtime. WebAssembly is a format browsers can run quickly. The results are checked against PCSX2's original code to make sure they match exactly. The graphics renderer was also ported to WebGPU, the browser's modern graphics interface.
• Optimization: This took the most time. For every idea, Claude had to check that the image stayed pixel-identical, and keep a log of all attempts, including the discarded ones.

How well does it run?

The developers tested Guitar Hero, GTA San Andreas, Final Fantasy XII, Dragon Ball Z Budokai Tenkaichi 3, Naruto Shippuden: Ultimate Ninja 5 and Resident Evil 4, mainly on an M1 Max Mac and a Linux system with a Ryzen 7 7840U. According to them, many games run at or near full speed on their machines, but the most demanding scenes are slower. The Digital Trends writer played Final Fantasy XII and Burnout on a GMKtec M8 mini PC, and says both ran flawlessly. That's two games on one machine, which doesn't prove broad compatibility across the PS2 library. Digital Trends advises trying a game first rather than assuming the whole collection runs equally well.

Our take

TabStationToo shows that an AI assistant can do more than build small apps on a technically demanding porting project: a JIT replacement, a graphics port and optimization, all backed by automated comparison tests. The workflow stands out: a rules file, reference tests against the original and pixel comparisons, which seem to have caught bugs early. A caveat: all performance claims come from the developers or from a single test, and there are no independent compatibility lists. On the model, the post says "Opus5.5". Legally, nothing changes: you must own the BIOS and the games, and the project ships neither. It builds on more than 20 years of work by the PCSX2 team, which the developers explicitly acknowledge.