Show HN: RetroTick – Run classic Windows EXEs in the browser

[lqs_]

RetroTick parses PE/NE/MZ binaries, emulates an x86 CPU, and stubs enough Win32/Win16/DOS APIs to run classics like FreeCell, Minesweeper, Solitaire and QBasic, entirely in the browser. Built with Preact + Vite + TypeScript.

Demo: https://retrotick.com

GitHub: https://github.com/lqs/retrotick

[chromehearts]

This is so cool & I'm really amazed by it but I couldn't help laugh at the readme

> We strongly recommend contributing with Claude Code or similar AI coding tools. [...] Of course, coding by hand is also welcome.

Funny time we live in lol

[lqs_]

Ha — even the README itself was written by AI, including that very sentence. Funny times indeed.

[lqs_]

Hidden feature: right-click any executable and select "View Resources" to browse its embedded resources like icons, bitmaps, dialogs, and version info. It even supports viewing Delphi forms (though Delphi programs can't actually run yet). Think of it as a browser-based Resource Hacker or eXeScope.

[butokai]

Just a couple of hours ago I was thinking about this project from some time ago doing the same thing: https://github.com/evmar/retrowin32

I wondered how much of this could be done with an LLM agent, and here we have the answer

[lqs_]

I actually contributed to retrowin32 to get Solitaire running there. Back then the only AI tool available was Copilot, and it took me several days just to get the main window showing, without menus or dialogs.

The current state of RetroTick was achieved in less than one hour using Claude Code.

[jeroenhd]

Seems to run a lot faster than the previous proof-of-concept I've found (https://www.boxedwine.org/app). Then again, that website runs an entire Linux VM to support Wine.

[lqs_]

RetroTick's CPU emulation is actually slower than JIT-based emulators. It feels fast because the Win32 API calls are native JavaScript, not emulated system calls.

[smusamashah]

I can right click and inspect HTML. I was thinking it will all be rendered on a single canvas. It's not. All the window elements like buttons, title bars etc are html divs. This is awesome.

[hard_times]

I wonder if this is the future of "I need to run my legacy Windows enterprise app on modern hardware"?

I suppose we're also not limited to WinNT look and feel, and can render dialogs, buttons, windows with any CSS framework?

Although, as the cost of building software is tumbling down, it will make more sense to re-build from scratch, targeting whatever runtime or platform you need.

[theragra]

Ive found that app my student team created for load testing of hammer drills for local factory is still ticking!

We created it around 2004, for Windows XP. Used Borland C++ and Windows driver for LPT port. Driver was written in asm, just for fun.

Since then, factory changed hands two times, and relocated from EU to China. 20 years, and Windows app still is working. I think they ran it on even on windows 98 at first.

[Tepix]

Tried it with REVERSI.EXE from Windows 3.0 from https://winworldpc.com/download/c2bbc28f-177a-c2b2-5311-c3a4... DISK02.IMG

(you have to first uncompress it, for example with 7zip).

    $ sha256sum REVERSI.EXE
    a9e319c8f479d1568beec03858fdbb27c71747b2bbed6cd7c9f5e2daa23b40e9  REVERSI.EXE

Result:

The game starts, it begins rendering the board, but then hangs.

[fao_]

Really doesn't surprise me, to be honest:

> We strongly recommend contributing with Claude Code or similar AI coding tools.

[lqs_]

Win16 GDI support is still pretty incomplete. There's a lot of work left to do there.

[lqs_]

It is fixed and fully playable now! Board rendering, mouse input, and the About dialog all work.

[realityfactchex]

Cool concept. I tried six different old Windows executables from programs I wrote way back when.

FWIW:

* My old VB 6 .exe apps all fail with "Reason: Unimplemented API: MSVBVM60.DLL..."

* My old QuickBASIC .exe apps fail in various other ways ("Illegal function call", etc.).

Keep on hacking.

[hypercube33]

To be fair windows didn't even have this if I recall you had to ship it with your executable

[LinusU]

This is super cool!

Checkout retrowin32 for something similar but written in Rust and not specifically targeting the web: https://github.com/evmar/retrowin32

[lqs_]

Thanks! I'm actually familiar with retrowin32. I even contributed a few commits to get Solitaire running in it. But Rust has a steep learning curve for me.

[maniazi83]

This is seriously impressive. Emulating x86 + stubbing enough Win32 APIs in the browser is not trivial.

How are you handling system calls that expect filesystem or registry access? Are those fully stubbed/mocked, or mapped to some in-browser virtual layer?

Also curious how you’re handling performance for heavier binaries — interpreted JS/WASM core?

[lqs_]

Right now, the file system and the registry are virtual. They are stored in the browser using IndexedDB. When a program reads or writes files or registry data, it goes to this virtual storage, not the real system.

For performance, the CPU is fully emulated in plain TypeScript. It does not use WASM or JIT yet. It is still fast enough to run simple programs from about 30 years ago. In the future, JIT optimization may be added to improve speed.

[starshadowx2]

I tried 22 old game EXEs I have and none of them worked. They would import and show the icon and some would open, but nothing would work and most wouldn't even close. They would either show various error messages when trying to open or just open in a broken/unusable state.

[SLWW]

Can you list them?

[pathartl]

I had a not-really-similar idea of hooking Windows GUI APIs and exposing them over websockets to create a psuedo-RDP and rendering the UI in the browser. My purpose was to provide a remote interface for old dedicated game servers that can only be controlled via a GUI.

[DustinBrett]

I love how quick it is and that it can run screen savers. My site has a similar concept with drag and drop but is using BoxedWine behind the scenes so it's a bit slower to boot up. Also very cool the "View Resources" part.

[TechSquidTV]

Please let me plan Sim Theme Park. I can't seem to run it on Crossover on my mac.

[lqs_]

Sim Theme Park is probably too modern and complex for the current state of RetroTick, unfortunately.

[ale42]

Funny project...

Tried to run SHELL from QBASIC, but it crashes:

  D:\qbasic.exe has encountered a problem and needs to close.
  
  Reason:  illegal instruction
  Address: 0x00002fee

[lqs_]

DOS interrupt support is still limited. Running SHELL would essentially require implementing a full MS-DOS COMMAND.COM, which is a significant undertaking.

[stuaxo]

Oh, I did exactly the same :D

[b3lvedere]

Aww. The FreeCell cheats don't work, except for -1 and -2 :)

[lqs_]

Just added keyboard shortcut support. Ctrl+Shift+F10 should work now!

[haonnoah]

Pretty cool. The pipes program doesn't seem to have color. Thoughts on making programs launch from a URL parameter? IE Launching a screensaver or game?

[lqs_]

The missing colors are likely due to some texture bugs in the OpenGL implementation. As for URL-based launching, that's definitely on the roadmap, but I want to reach broader EXE compatibility first.

[stuaxo]

Not sure shift is working. I tried using QBASIC but couldn't type : only ; because of that.

Then I tried running the program SHELL and it crashed.

[ddgflorida]

Nice. QBASIC FOR i = 1 to 5: PRINT i: NEXT hung up after 4. The shift key didn't work in the Qbasic Editor.

[itintheory]

Seems like the .scr files trigger CrowdStrike Falcon. Not clear where the executables run here come from...

[cluckindan]

Probably because .scr is not meant to be run directly, but malware regularly does that.

[Dwedit]

Not enough Shell32 to run Winfile or Notepad.

Also the command prompt won't list directories for some reason.

[lqs_]

Notepad from Windows 2000 should launch now, though it's rendered as a simple textarea without full functionality. The file system API still needs a lot of work.

[em3rgent0rdr]

Impressive. Noting however that double-clicking is not working in Minesweeper. :)

[ThrowawayTestr]

Can it run doom?

[tty456]

Winamp 2.x would be great to add if allowed!

[alfiedotwtf]

Whoa, this is pretty sick!!

[KellyCriterion]

they even have SSMAZE.SCR, that 2.5D rendering screensaver! :D

[cluckindan]

Now where’s that Screen Antics Johnny Castaway floppy disk…

[wertyu123]

Nice