Porting my 1993 Amiga game to Godot, with an LLM reading the 68000 assembly

rrabahs about 5 hours ago 28 commentsRead Article on babyloniantwins.com

ES version is available. Content is displayed in original English for accuracy.

These are my notes from porting my Amiga game, which I originally built in Baghdad in 1993 in MC68000 assembly, to Godot, using Claude Fable 5 during last July holiday. It took an evening! Getting the feel right and shipping it took a few more weekends and evenings.

I spent the last few weeks analyzing what Claude did, feeding it my 33 years of memory of how I built the game, my notes and the git repos. It wrote the first draft of the article, and I edited line by line over a week. The screenshots of my 1993 map editor is the first I have run it since then. The one thing I never verified myself is the 108-byte explanation.

"Before starting everything, the model assembled the code using vasm on my Mac, and kept going till the binary is byte-identical to the binaries I had in my original game. Even after that, the there was mismatch of about 108 bytes. I originally used AsmOne which assembles into memory, and the game saved into the disk by saving that memory after running the game. So the original shipped files are a snapshot of the game that had already been running, not clean asm-one output."

Please post any questions. I am also releasing the original game for free.

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Discussion (28 Comments)Read Original on HackerNews

btbuildem•about 1 hour ago

> one copy of the Amiga Hardware Reference Manual

aka The Book... my, this brings back dusty memories

Babylonian Twins has such strong "Gods: Into the Wonderful" vibes, I wonder if that game was an inspiration for you

https://www.lemonamiga.com/game/gods-into-the-wonderful

https://www.youtube.com/watch?v=1kAXGjUwHyA

rabahs•13 minutes ago

The main inspiration for Babylonian Twins that nobody mentioned or even thought about was https://en.wikipedia.org/wiki/The_Maze_of_Galious it predates them all.

robviren•about 1 hour ago

I'm actually glad to see it stumbled in a few areas. Always surprised to see how much it gets right though. I had always hoped the rather obscure parts of computer history and games would be this incredibly difficult area for Agents to mine.

The amount of non standard hackish and obtuse things that had to be done to implement things in the past feel impossibly complicated to touch today. Lots of people made it up as they went along and used the hardware in ways no one expected. Reminds me of Tim Follin doing the audio for Plock on SNES and Miamoto being shocked the audio was real. It would be so interesting to see what we could learn about development of the past from agentic insights into how code was constructed. I love stuff like this an appreciate the in depth post.

ericd•about 1 hour ago

Wow, that's gorgeous for something written in assembly, running in 512k, nice work!

efficax•30 minutes ago

amigas were way ahead of their time. We had an Amiga 500 and then got a 386 and it was such a downgrade, but the Amiga was clearly a dying system.

hedgehog•about 5 hours ago

This is fantastic. It would be interesting to have Claude Code export an engineering guide for doing similar ports, including descriptions of the tooling it built to do it. I've done some reversing from binary but never with results this good.

rabahs•about 5 hours ago

This is a great idea. It could be a generic game porting skill to make the porting experience smoother. After my experience above. I have actually tried giving Claude binary files of games and it was able to reverse engineer to GoDot!

hnlmorg•3 minutes ago

Dumb question this, but how do you load it into Claude? I’ve only seen APIs for text and image uploads. Not random files. Or maybe that’s a limitation of the SDK I’m using?

sedawkgrep•about 1 hour ago

> I have actually tried giving Claude binary files of games and it was able to reverse engineer to GoDot!

Oh wow...I hadn't even thought of trying something like this. There are soooo many games from that era that I'd love to play again without the hackery of emulation.

rabahs•38 minutes ago

Just grab any game, especially old rom files form the 80s (I tried TimePilot and Road Fighter from MSX era). The model extracted the graphics, the sounds and then built the whole game. It takes less than 1 hour to port a 16kb rom file, in one shot. You will get a playable game, but you need a few follow up prompts to get it back to its original form. Usually some sprites or sounds issues, but very easy to fix, if you have played the original game.

ericd•about 1 hour ago

Yeah, someone reverse engineered Red Alert 2 recently. Took Fable cranking for almost a month, but it's pretty amazing to see.

asimovDev•about 1 hour ago

session stored on the drive would also contain all of the tool calls , right? unless op changed the default settings it would've expired though by now, since the run was in July

rabahs•11 minutes ago

That's a good point. I looked at the git history for my analysis. What is the best way to analyze claude sessions history? I definitely check if I still have them stored. Thanks

sgt•about 1 hour ago

Very cool! Wish you had released it back then

rabahs•2 minutes ago

Thanks. I know the Amiga version took a long time. It was very hard to even look at the assembly code I wrote after so many years. AI was the hero that explained everything and helped me to package it for releasee. Enjoy!

byako•about 1 hour ago

porting a 93 game with an llm reading 68k assembly while i'm over here struggling to refactor last month's javascript. we are not the same. seriously cool project though

a2ff6eeb0•about 1 hour ago

> Please post any questions.

Since Claude did the port and apparently understands it better than you do at this point, can we ask Claude? Is there a git repo we can point Claude at to interrogate it on the way things were done? Maybe you can share the transcripts you used to port it?

rabahs•about 1 hour ago

This is actually what I did to understand what happened during the port. I did analysis weeks after the game was ready.

While doing the analysis, I came to know about this 108 byte delta. I didn't quite understand the explanation Claude gave me. I added more details about this in the post above. It could be the difference in the assembler used, the environment used (Amiga 500 vs M5 Macbook), or how the binary was saved from memory 33 years ago

mattbruv•about 2 hours ago

I really tried to start reading this because I am interested in the idea, but the obvious AI writing prose is just so off-putting that I can't force myself to continue reading it without my eyes rolling into the back of my head. I'm not against using AI to code, but if you're actually passionate about the project and want to share it with others, you should use your own words.

dang•about 1 hour ago

I mentioned the same thing to OP by email, but this story is too good to block on that.

aenis•about 1 hour ago

To me, someone with interest in amiga games and low level assembly ports, having that write up being done by hand wasn't load bearing.

Though I'd admit that using claude for a few hours every day this year desensitivized me to its prose :-)

khazhoux•about 2 hours ago

There were a couple of AI tropes but not overly so. This is a great story, especially if you’ve programmed the Amiga before.

Think of it as: this is a story that quite possibly would not be told without AI to help with the writeup.

rabahs•28 minutes ago

Your last point is exactly right. I wouldn't have had the time to do this port and write-up without the help of AI. Having said that, the AI wrote this based on my own notes and I edited and reviewed every line over a week. AI also helped with extracting screenshots and code snippets which would have taking me more time. I don't like to read AI writing either, but I thought that the fact that this is based on my own notes and experience and using original code and screenshots from the 90s would be of interest to the community. Thanks

sitkack•30 minutes ago

Tics, tropes are worn out predictable plot devices

lstodd•about 1 hour ago

What's the point though? If you got the stuff it's better run in UAE. If you have none I don't trust you and therefore think the Amiga name is misleading. To gain trust here show some code running in UAE.

There is no point in "porting to Godot" because either you port Amiga stuff to UAE-likes or FPGAs or you in fact advertise "AN AI REWROTE MY CRAP GWBASIC GAME FROM 93 LOL". Lol. Which is riduculous.

and people will just laugh.

also 68k asm is actually human-readable compared to x86.

urbnspacecowboy•25 minutes ago

This is inordinately harsh, though I agree with wanting to just play the original Amiga game. It's available at the following link from all the way at the bottom of the article: https://bithunch.itch.io/babylonian-twins

lstodd•19 minutes ago

It's not harsh.

It's the talk one should receive when they fuck up. It is how people learn.

rabahs•22 minutes ago

Thanks for the feedback. If you have read the article, I also mentioned that I have released the Amiga version for free to the Amiga community. AI actually helped addressing a few bugs and get it ready. You can download the ADF and play the full Amiga game for the first time since 33 years ago. This post was more about my experience using AI and interacting with assembly code from the 90s.