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

Posted by rabahs 5 days ago

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.

Comments

Comment by gmerc 4 days ago

It's a completely new world. Random retro games I ported to modern webgl/webgpu in the last few months:

- The Adventures of Robin Hood - Opus 4.7/Sonnet https://robin.tooclever.org

- Syndicate - Sol/Luna 5.6/Opus ( https://this.os.isfine.org/blog/posts/modern-game-port-syndi... )

- Kaiser 2

- Populous Plus - Sol/Luna 5.6/Opus

- Dragon Strike - (Fable 5.1 almost one shot)

- War of the Lance - Qwnen-3.7-27B-dense (got stuck, finished with) Qwen-3.8-Flash-Next https://this.os.isfine.org/blog/posts/what-reverse-engineeri...

- Dungeon Keeper - Various

- Red Baron - Opus 4.8, DeepSeek 4

- Test Drive 3 (Qwen-3.8-Flash Next, DeepSeek-4-Flash-exp, GLM-5.3-Flash)

- In progress Ultima 6 ... to 3d (Fable, GLM-5.3) ( https://this.os.isfine.org/#ultima6-atlas )

Some straight source ports (Kaiser), some full RE jobs (Dragon Strike, Test Drive, WOTL)

Some a mix of available sources (Syndicate, Populous)

Some of the findings are documented here: https://this.os.isfine.org/blog/

Comment by iamflimflam1 4 days ago

Let me add my elite clone - https://harmless.atomic14.com

Comment by s-macke 4 days ago

I would like to see all of them :-)

One of the most difficult reverse-engineering projects from that era for me was Stunt Car Racer on the C64 (also ported to DOS). It features a highly optimized 8-bit 3D graphics and physics engine. Fable was the first one that was able to generate a complete port of the game.

Now I am trying of Flight Simulator 4 and Wing Commander 1. Then maybe Frontier Elite 2. So much fun ....

Comment by gmerc 4 days ago

Strike Commander is in the works. I tried a few months ago and got quite far asset wise but stalled on the flight model, I will probably see how Fable 5.1 does from zero after this weeks limit reset. I imagine it will be able to get quite far.

Comment by aidenn0 4 days ago

Strike Commander, a.k.a. the game that required QEMM386 to actually work. I do think it was the last game I got that came with a really nice manual though.

Comment by p0w3n3d 4 days ago

Please do not hesitate to share stunts, if you can

Comment by s-macke 4 days ago

Stunt Car Racer from Geoff Crammond published by MicroProse, not Stunts from Distinctive Software.

Comment by gilleain 4 days ago

Syndicate!! Actually, this one feels especially appropriate to use an LLM for.

Comment by shevy-java 4 days ago

Some old games have high re-playable value. Syndicate is one of them; UFO enemy unknown is another one, as is civilization or Masters of Orion 1. I can reply most of them quite fine. Populous was also quite decent but not quite replayable compared to the others mentioned IMO.

Comment by Steve16384 4 days ago

This is amazing. I'm trying to get a handle on how you're doing this, but I can't seem to find anything specific. e.g., is it a case of prompting "Please recreate Populous for the web"?

Comment by gmerc 4 days ago

This post has the actual prompt used for one of my ports and the stack, and there's more info below it under "further reading".

There's really nothing much to it, all the knowledge needed is in the weights of the model, so regardless of what you want to do, you can ask "if I wanted to do this, what would be the best way / best practices to get there with my machine"

https://georgzoeller.com/blog/posts/what-reverse-engineering...

Comment by s-macke 4 days ago

I use a step-by-step approach:

1. For each topic, write a result Markdown file in `spec/`.

2. Identify the file formats.

3. Reverse Engineer and extract all assets, followed by manual review. This works in 90% of the cases.

4. Determine the compression/packing used for the executable. Most binaries used one of roughly five common executable packers.

5. Unpack the executable manually.

6. Use an ancient free IDA-Pro for disassembly, or a modified DOSBox to determine all code/data blocks and the relevant segment-register values for the 8086 architecture. In the second case I use my vibe-coded disassembler.

7. Identify the major functional domains in the disassembly and split the files accordingly.

...

Comment by muro 4 days ago

you are awesome. I'm doing one such port and it's not that simple :)

Comment by LordDefender 4 days ago

Red Baron! Wait, how, where, from Amiga? Tell me more please!

Comment by gmerc 4 days ago

https://redbaron.tooclever.org Demo, requires WebGPU - PC version but with modern upgrades (can be disabled), Opus redid the plane models and turned everything proper 3d, plus added ww1 frigates, flak searchlights, etc.

Comment by mt_ 4 days ago

ai slop port is not a port, re-creating the full game engine to run in natively a modern cpu architecture that is the challenge

Comment by gmerc 4 days ago

Using a car is not a way to travel, the real way is to take a horse.

Comment by hippietrail 3 days ago

Writing without uppercase letters or full stops is not writing. Low-effort is low-effort. Slop is slop.

Comment by jdw64 4 days ago

wow really nice!!

Comment by mattjoyce 5 days ago

A few weeks ago I downloaded a memory dump of a zx81 game, and ask Claude to build it in Go. It nailed it. Converted the binary back to basic and then to go. My idea was that the game would be unknown to llm training and perhaps a nice bench.

What a crazy thing it is to be first at the advent of personal computing, and then in the inflection point where AI treats that first experience as archeology.

Comment by EagnaIonat 4 days ago

I tried this as an experiment with the hobbit tape file to Godot. Worked, and I was quite impressed in how it deconstructed the binary. At one point it did cheat by looking up the zx81 Hobbit online to find pieces that were missing.

Comment by rabahs 4 days ago

Curious if you had to do any follow up prompts. How large was the binary and which model did you use?

Comment by btbuildem 5 days 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

Comment by rabahs 5 days 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.

Comment by anonzzzies 5 days ago

Ah! How many times I played that game. I missed it on the Amiga after and never unfortunately saw your game. Those old MSX games just had good ideas.

Comment by larodi 4 days ago

"Gods: Into the Wonderful" is perhaps the most amazing and inspiring game of the early 90s that literally blew my mind the first time I played it. Been playing it on and off for more than 15 years afterwards. It is a shame that publisher went down, they also released some other good games, but GODs is the legend among them.

Besides, if it wasn't for BBSs and pirated software, we'd never be ever able to put hands on it, as my country was going through regime change in 1989 and in 1992 the economy was completely mashed down and the game's price was half my mother's salary at the time. What a time to be alive. Of course it was not dad, but a friend who dug it from some BBS or perhaps the eraly tucows archive.

Comment by parlortricks 4 days ago

I remember playing Gods, was a great looking platformer.

Comment by dannyobrien 5 days ago

I just wanted to add how much in awe I am at you creating this game in '93 in assembly. Around the same time I was trying to write a game on the Atari ST, and the dedication to the project -- especially when documentation was so thin on the ground, pre-Internet -- is extraordinary. Do you have any stories from debugging the game? I always found that the most dispiriting part, after the endless hope of handcrafting the code that I was sure would work first time...

Comment by rabahs 5 days ago

Thank you for sharing your experience. It can be hard to remember all the details of debugging in assembly, but the main aspect I recall was managing game performance to ensure all rendering and processing stayed within 1/50 of a second. My technique was drawing a white line using the Amiga Copper, starting at the beginning of the top vertical blanking period. As I added more game objects, logic, and rendering, I had to make sure the line does not drop below the beginning of the active display area. If it went below that point, a frame would be dropped, resulting the game to flicker. I had to use many techniques to split the processing of the game objects in batches across multiple frames. Fun time.

Comment by TacticalCoder 5 days ago

> 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.

Sooooo cool! I did something similar a few months ago: had the old source code (and executable files) of a game I wrote in 1991 (PC DOS) and a few notes in source code and, well, my old memories of how things worked. I didn't know how to compile it anymore but with the help of LLMs I managed to get it compiling again.

Since then I found about 8 pages of handwritten notes I took back in the days and I did immediately scan them and I added them to the repo.

Now my PC DOS from 1991/1992 does compile again and, well, I really should blog post about it one of these days (if only I had a blog...).

Comment by rabahs 5 days ago

Thanks for sharing. It is truly an amazing feeling when AI helps us excavate the past. I never thought I would be able to do so. I'm so glad I kept all my files over the past 33 years.

Comment by rererereferred 4 days ago

You can pout it on itch.io and write a devlog there.

Comment by rabahs 4 days ago

It is already on itch. Check the babyloninantwins.com for all the links

Comment by cesaref 4 days ago

I noticed he mentioned that his game was running at 50hz - that's true if an Amiga is running on PAL, but if it's a US machine it'll be 60hz when running with NTSC.

Back in the day, most Amiga games were made in Europe, so were tuned for 50Hz refresh, and played 'normally' over here. At 60hz, they would feel wrong, and likewise, US games could feel sluggish and unsatisfying.

Locking the machine to the monitor refresh rate in this way was a curse but also a blessing. It allowed the machines to drive a standard television in various regions, although the image was somewhat blurry, but also the use of dedicated monitors once you started taking it seriously. This reduced the price point and allowed lots of kids to convince their parents to get one :) The higher resolution modes just didn't work out though, so lots of stuff targeted the 320x256 resolution.

The surprise benefit was also that the amiga could genlock to a TV signal and used to overlay onto a video feed, leading to many interesting cheap graphics overlay capabilities which were otherwise totally unobtainable by small TV channels or enthusiasts.

Those were happy days.

Comment by Gamemaster1379 4 days ago

Neat project.I've been experimenting with making reusable console porting frameworks since last October. Opus 4.6 was my first success with the NES 6502.

Since then I've done static/native ecosystems for the Super NES, GBA. Nintendo DS, Playstation (most popular) and even Sega Genesis, such also uses the 68k.

https://github.com/mstan/segagenesisrecomp

I even extracted the 68k decoder to its own repo because I wanted to reuse it for the Phillips CDI.

Sega does Sonic 1 2 and 3&K. Also Rocket Knight adventures. Still early yet though. CD-I does the BIOS. Didn't get a game running end to end yet though.

Comment by pixelpoet 4 days ago

Rocket Knight Adventures!!! Immediately I can hear the music in my head, and I haven't thought about this game in a long, looooong time! Thank you for mentioning it, I'm off to get a Mega Drive emulator :)

Comment by rabahs 4 days ago

Cool. I wonder how much additional harnesses would improve the porting process. In my case, I gave more freedom to Fable 5. The model was able to figure things out. I am hearing that the latest models works better with less restrictions. Curious to know the progress on the above.

Comment by Gamemaster1379 4 days ago

If you want to see a bit more in depth, some shameless plugs but here's a few articles I've written as I've made progress:

https://1379.tech/building-enhancing-recomps-ecosystem-updat... https://1379.tech/recomp-ai-5-months-later/

Ultimately, Sega Genesis has been low priority. I've been focusing mostly on community feedback for my existing ones. Playstation is by far the most popular and the one I get the most PRs on. SNES is second. And right now Nintendo DS is newer, but has a very popular Metroid Prime Hunters I've been working a ton on.

NES and Sega Genesis get little attention. CDI and VirtualBoy [understandably] get no real attention.

I have an early original Xbox LLE prototype. Hoping to do more with it soon, but I'm all tapped out of usage at the moment. I got a lot done during all the crazy resets with OpenAI there for a while.

Comment by hedgehog 5 days 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.

Comment by rabahs 5 days 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!

Comment by sedawkgrep 5 days 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.

Comment by rabahs 5 days 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.

Comment by WarcrimeActual 4 days ago

So by old ROM files, you mean still PC games or MSX, Sega, NES, SNES? And when you have them in place what do you specifically ask Claude? This is interesting and I'd love to see if it can get me porting old games with zero coding knowledge.

Comment by rabahs 4 days ago

Yes, you can try your game out. I tried with old msx rom files and it worked.

Comment by ericd 5 days ago

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

Comment by asimovDev 4 days ago

https://github.com/harshilmathur/openra2

this is the closest thing I could find. do you have a link to the reverse engineered RA2? I am surprised I do not get any recent repositories or forum posts about this, you'd think it would be more talked about

Comment by hnlmorg 5 days 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?

Comment by rabahs 5 days ago

With Claude Code command line, you can point to any directory you have in your file system. In this case, Claude Code was working across three directories: the original game in assembly, the 2010 port in C++, and the new Godot port.

Comment by Steve16384 4 days ago

This is amazing. How long did that process take? Was it almost just a case of giving Claude the binary files and then prompting "please recreate this in Godot"?

Comment by rabahs 4 days ago

I tried it with 16k roms. It does take less than 1 hour but if you want to tweak and make playable, you will need half day

Comment by ecliptik 5 days ago

I'm doing something similar for DOS SDL ports. Repo isn't public yet, but idea is to have a repo with a knowledge base, skills and patches agents can use when porting to avoid having to bootstrap everything from scratch.

Comment by 1313ed01 4 days ago

Porting to DOS sounds like a great plan for retro games, to only have to do the port once and know there are stable emulators to run it in, as opposed to porting to some modern OS and then have to port the game again and again to keep up with API changes.

Comment by ndiddy 4 days ago

I'm assuming they mean SDL ports of DOS games. SDL is actually one of the most stable libraries that a native game can use. They make breaking changes to the API once every 10-15 years, and they write a compatibility layer that implements the previous version's API using the current version's API as a backend. This has happened twice so far, so there's an SDL 1.2 implementation that uses SDL 2 and an SDL 2 implementation that uses SDL 3. These can be chained together, so for example you can run an SDL 1.2 game from the early 2000s on a modern Linux system and it'll have native Wayland and Pipewire support thanks to using SDL 3 behind the scenes.

Comment by asimovDev 5 days 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

Comment by rabahs 5 days 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

Comment by asimovDev 5 days ago

sessions are stored in the home folder somewhere but are deleted after 30 days by default. it won't be stored in the bash history, at least it does not for me on macOS with zsh + omz

Comment by b112 5 days ago

Of course is one does nightly, off site backups, all is well! A friendly note to all, always have backups!

Comment by robviren 5 days 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.

Comment by seobotaicom 4 days ago

Do you think AI could actually help us discover techniques from old games that were never documented by their original developers?

Comment by kschiffer 4 days ago

I did Moonbase Commander, in JS and HTML canvas. Currently building an AI opponent that doesn't suck as much as in the original.

It's amazing that this is possible. I took quite a bit of steering and was definitely not a one prompt endeavor but having a lot of fun with it.

Comment by ericd 5 days ago

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

Comment by efficax 5 days 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.

Comment by ericd 5 days ago

Yeah, my cousin had one, was like a computer from a parallel evolution chain, kind of weird, but kind of awesome.

Comment by nnevatie 4 days ago

Looks like a pretty de-facto Amiga game of the era, to be honest.

Amiga 500 (and 1000 prior to it) supported smooth scrolling by simply setting the screen-visible pointer in memory.

Comment by snvzz 4 days ago

From the article:

move.l #$dff000,a0 ;Base for hardware registers

lea save(pc),a1 ;Get the system

move.w #$4000,intena(A0) ;from the AMIGA

Crude, although perfectly fine in practice. The system-friendly way is to call the function exec.library has for the purpose, Disable()[0].

0. http://amigadev.elowar.com/read/ADCD_2.1/Includes_and_Autodo...

Comment by rabahs 4 days ago

Thanks. I wonder if that was documented in the Amiga Hardware Reference Manual :) that was the only book I had back then. I remember it was mostly registers and assembly language.

Comment by snvzz 2 days ago

You're welcome.

It's all in the NDKs, which I didn't have at the time, either. I only got my hands on the AHRM once I started university, and that was after 2000.

Having very belated fun with Amiga development today. It's never been easier to get into, with all the archived tools and books, and the modern ones.

Comment by coder-pm 5 days ago

Hmm did you ever run the game port against the original one in UAE? With the same inputs? Or is it just "it plays right when I play it"? That 108 byte delta is puzzling...

Comment by Lerc 5 days ago

There are a few instructions that are functionally equivalent. It is possible that one of the assemblers has the ability to auto convert equivalent behaviour instructions into smaller instructions that do the exactly the same thing. That is fairly common in assemblers. If one of the assemblers had a normalisation phase where they treat multiple forms of the same instruction as the same thing prior to checking if a more compact encoding is possible then that normalisation phase could be generating a same size instruction with same behaviour but with a different encoding. A small number of bytes different with same behaviour is what I would expect from a reassembly like this.

The proof of the pudding would be to have a look at what the differing bytes were encoding.

Comment by coder-pm 4 days ago

Ok but if assembler normalises encoding then a byte diff won’t prove anything. Behaviour check is the way.

Comment by rabahs 5 days ago

You mean run them side by side ? No, I did not do that. I played the ported game on my Mac only. The movement feels right based on my thousands of hours playing the original. There was only small tweak I had to make the trampoline jump, but everything else ported so smooth. I think the decision that Claude made not to use Godot physics and just port everything as as, made the gameplay feels right without much tweaks.

Comment by coder-pm 4 days ago

Nice, so it works quite good! So it’s a port, not a re-implementation. Good job on that, I like it that way:) do you have an idea why the trampoline jump didn’t come across?

Comment by rabahs 3 days ago

The trampoline jump physics was correct. The issues was that the 2010 c++ version ignored a held button because of an Apple TV workaround I implemented when I enabled support of tvOS 10 years ago. Godot port read it as pressed, so you get high bounce without a fresh press: https://babyloniantwins.com/blog/porting-a-1993-amiga-game-t...

Comment by coder-pm 3 days ago

Oh so it’s about the platform where it lives, not about the logic, fair enough. Porting logic as is looks like the best approach, the one thing that broke wasn’t really logic:)

Comment by Lerc 5 days ago

Have you been following the videos on Youtube of the Amiga port of Sonic?

Their approach to replicating the behaviour is to run the original game logic. The display has to be totally rewritten but they had the advantage of 68k for both machines.

I don't know of any games that used the blitter for calculation like some programs did for MFM decoding, that might have presented quite the porting challenge.

Comment by rabahs 5 days ago

No, I have not. I will definitely check before releasing the Amiga port inside the Steam. I think that would be the right approach, especially if you are porting a game you have not played enough. I did use blitter for all graphics. Now you mentioned MFM, I remember I wrote some disk copy protection code back in the day that leverages MFM encoding. I will check if that code is still around.

Comment by abrookewood 4 days ago

Must be incredibly rewarding seeing your game rebuilt. Fantastic bit of history too - I had no idea games were being made for the Amiga in Baghdad!

Comment by rabahs 4 days ago

The game website link to some articles description the game dev scene back then.

Comment by Sharlin 5 days ago

What I'm interested in is performance and memory use. How many times less efficient is the 2010 port compared to the original? What about this new one?

Comment by rabahs 5 days ago

Are you interested in comparing the 2010 remake (C++) to the original (Assembly)? They are quite different games, so hard to compare, but both run at peak frame rate for their respective platforms (60fps vs 50fps).

I have not compared the 2010 port to the current Godot port. However, I felt the Godot port was smoother. I think that was because Godot uses the latest graphics frameworks (e.g Metal) vs old Opengl ES 1. It would also be interesting to compare the godot port of the original game vs the original in assembly. Curious how I can achieve that. A good question to ask Claude.

Comment by Sharlin 4 days ago

> They are quite different games, so hard to compare

Yeah, that's fair. I was just wondering what the performance of a modern version as close to the original would be, if written with Godot or another vastly higher-level framework than handwritten assembly. Given the 3+ orders of magnitude difference in processing power and memory.

Comment by rabahs 4 days ago

The fair comparison is between the assembly version and its godot port. I didn't actually notice any performance difference since th game is capped by its 50 frame per second.

Comment by Sharlin 4 days ago

Yep, at equal resolution the game should presumably run at at least 10000fps uncapped on a modern machine. Of course that's not how it works in practice due to bottlenecks in the input stack and elsewhere.

I also doubt the Godot version fits in 512kB of RAM ;)

Comment by glimshe 5 days ago

Great work! I'm planning to do that to another forgotten game (not mine) and it's great to see that this is now quite possible.

Comment by rabahs 5 days ago

Thanks! Yes, this was not possible last year, and probably even a few months ago. Amazing times to revive forgotten games and software. Let me know if you have questions on my process.

Comment by saulpw 5 days ago

Which game are you planning to do? We all should coordinate so we're not doing the same games repeatedly.

Comment by glimshe 4 days ago

Ah, it's not going to be Amiga. The shortlist has two PC and two C64 games.

Comment by saulpw 4 days ago

Yeah I'm working on a C64 game myself (Below The Root). Are yours a secret?

Comment by glimshe 3 days ago

Not at all - I'm just not mentioning names because I don't want to discourage anyone to get started before I decide that I'm ready to work on ANY game. If I do it, I'll ping you here :).

Comment by byako 5 days 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

Comment by ropable 4 days ago

Thank you to the effort of building this game in the first place (I'm sorry that I never got to try it then), and thank you for re-introducing it to us today. I'll give it a proper play in my leisure time.

Comment by rabahs 4 days ago

Thanks! would love to hear your feedback.

Comment by appstorelottery 4 days ago

Anyone that uses "Claude Fable 5 running in Claude Code"? Can you speculate that plan or cost might have been involved in doing this (given that it seems approximately 5 hours or so of continuous operation for both C++ and Assembly ports, along with the shipping / marketing functions where it's not clear how much compute was used". Thanks in advance (I'm thinking of trying US based models, however I'm penny pinching using DeepSeek Flash etc. ATM).

Comment by gmerc 4 days ago

I just did a one shot port of Dragon Strike (1990) and it got to about 85% playable from zero. Cost: About half a Claude Max 200 Weekly Limit, whatever that means. Details: https://www.linkedin.com/posts/georgzoeller_fable-51-is-a-si...

Comment by rabahs 4 days ago

I have the Max subscription. I use mostly weekends and some evenings. I never hit a limit.

Comment by larodi 4 days ago

Love the GFX and the whole idea that s.o. under sanctions can create this game in 1993 while outside is 50' is itself amazing.

Comment by sgt 5 days ago

Very cool! Wish you had released it back then

Comment by rabahs 5 days 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!

Comment by sgt 5 days ago

How was Baghdad like in 1993? All I remember from that time was the Gulf war, Saddam and much conflict. I can only imagine how it would be finding hardware, books and resources such a time. That was hard enough even in parts of Europe.

Comment by rabahs 5 days ago

Yes, it was a tough time after the war, but the main difficulty was the economic sanctions, which hit us hard. There are a few interviews and news articles published after I launched the mobile version back in 2010 that discuss our experience in the 90s. You can read more about it here: https://babyloniantwins.com/story/ I am happy to go into more detail on any aspect. I will be watching this thread regularly.

Comment by pkilgore 4 days ago

This was an interesting read, in that it was obvious both that Claude was used in part for the prose but that a human had definitely edited some of the worst claudish out of it (but not enough for me to be able to tell).

Confirmed in that last paragraph. Just interesting to me I can detect gradations of AI speak at this point.

Comment by smilbandit 4 days ago

I've been wanting to do some ports of old games i liked on the atari 400 i had as a kid. some of them I want to see if they would translate to a mobile web game. couple i'm looking to translate are Archon, lode runner, balderdash and maybe some of the ultima games, I really liked ultima 4.

Comment by shevy-java 4 days ago

> The same twin, the same six frames: 1993 above, 2026 below.

But why is the 2026 twin facing right when the original faced left?

It's only a minor detail, but IMO it would be easier for comparison if they both would point in the same direction.

Comment by rabahs 3 days ago

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Comment by deterministic 3 days ago

What an excellent read. This is why I read HN. Thanks!

Comment by rabahs 3 days ago

Thanks!

Comment by jeanmichelselli 4 days ago

This is a really cool project! Amazing!

Comment by Jach 4 days ago

It's kind of a fun, albeit also kind of a pointless, thing to do, huh? This week I took a student project game I made with 3 others back in 2010 and made it live again. I'm cheap, I only have the $20 plan for this month (likely to pause again for next month) and used Opus 5, and I'm visibly hamstringing it by running claude code in a firejail and not using yolo mode on permissions. Still, without much effort/oversight, it took the old C game that only ran in windows' cmd.exe terminal (a class constraint -- we still made a side scrolling shoot-em-up rather than a text adventure like many others), wrote the new version in Common Lisp as I asked (somewhat following the style of some other Lisp code I've written), implemented both a simple SDL2 "software" renderer along with an even faster OpenGL renderer, and didn't touch the original assets which were in a quirky binary format with a bug on one level in the C code. And now it runs great on Linux (and Windows, though only briefly tested it, building it with wine). Having its own graphics window lets it run at thousands of FPS when we were struggling to hit 30 back then. Last night on a whim I had it take a crack at porting to Android, and it did that as well. Still using SBCL, just one little C file shim for some things, no Java code was needed. Now I can easily show it to a few people in person. And it was kind of fun to play it again after so many years in an archives folder.

Your game looks cool. It's a full, real game! And while I now think that there's no longer strong "platform convenience" reasons to choose any tech stack if these AIs can just bulldoze their way through difficulties, I'm sure running in Godot still made a lot of things easier for it.

Comment by Steve16384 4 days ago

Why pointless?

Comment by Jach 4 days ago

Only kind of pointless. A few reasons come to mind. For one, they're games. (I say as an avid lifelong gamer.) For another, it's indulging nostalgia. (I say as an indulger.) To be clear, I think both things are fine, but of course to all things moderation, even moderation. When trying to rank things by pointlessness, many specific forms of entertainment and nostalgia are higher up than other activities or categories. Not as high as watching paint dry. And the more general category of, say, "having fun" is lower; some might even claim that to be the least pointless thing of all. I'd caution with "Amusing Ourselves to Death".

More reasons come from trying to predict where AIs and our interactions with them will be in 6 months, 1 year, 2 years, 5 years. Will we even be alive? Other reasons from wondering about alternative actions: is asking the magic box to do this particular thing, rather than some other particular thing, the thing that will actually bring you (or others) joy right now? Or money? Satisfaction? Fame? Upvotes? Some other things you want to feel or experience or do? (And in the OP's case, I think there's actually quite a good case of actions matching motivations, given the full history, and especially as earlier pre-AI-tooling ports were well-received enough to get a couple million downloads. Still, what about something new?) For my own small efforts this week, the main things I got out of it, besides the nostalgia (which is quite valuable to me), were similar to what I've been getting out of any AI-using projects this year, which is a strange mix of satisfaction, a bit of fun, a bit more awe at these magic boxes (even the dumber ones like Opus and Sonnet), anticipation of showing/telling a few people in person about this particular kind of pointless adventure, and a bit more melancholy about a few things, like the makeup of some of my online hangouts, or that my programming skills have been rapidly decreasing in their having a point to exist, or that my revealed preferences in this case are that I'm happier to let the AI do all the coding for this project and barely look at the code myself (there's a bit of disgust/gross feelings here too). I last thought of doing this work in 2019/2020, never got very far, now it's suddenly done, and even more than I thought of doing. (I still keep the AI out of some other projects, as programming the old fashioned way is in general still pretty fun to me at least.) Now it's on to the next project, when I decide that will be more fun than playing a game (I have such a backlog after all), and I'm sure it'll also be relatively pointless. More the honor to people doing bigger things impacting the world, with or without these tools.

This whole comment is also kind of pointless, I'd rank it as probably more so than the other mentioned things (except I guess watching paint dry), and yet it's here.

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Comment by caruasdo 5 days ago

It's interesting to know this.

Comment by a2ff6eeb0 5 days ago

> Please post any questions.

Since Claude did the port, wrote the article, 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?

It's marvelous that software can be written with minimal human input, but I guess I'm confused about why I would talk to the human that prompted the AI, rather than the AI that did the work.

Comment by rabahs 5 days 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

Comment by rmunn 4 days ago

> ... confused about why I would talk to the human that prompted the AI, rather than the AI that did the work.

One reason is because you can't talk to the AI that did the work, not unless the human who prompted it is able to hand you a file with the complete session and/or context data. (And I'm not at all certain whether Anthropic would allow users to obtain that kind of thing, since it would probably be extremely useful to people trying to distill their models. It's possible they might allow user A to say "Hey, allow user B" (or anyone with the link) "to access my session with GUID ba5eba11-1234-5678-abcd-0decafc0ffee", but I doubt they'd ever allow context data to be downloaded and passed around).

Without the context, you're talking to a different instance of the AI that doesn't have the memory of the instance that ported the code, so the answers you get won't be nearly as useful.

Comment by actionfromafar 4 days ago

Not to mention, the model has very little if any self insight.

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Comment by mattbruv 5 days 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.

Comment by dang 5 days ago

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

Comment by tomcam 5 days ago

I couldn't detect it from my casual read. English is almost certainly OP's second language so it seems much more forgivable.

Comment by dang 5 days ago

Yes, and that is unfortunately the worst of the fuzzy areas. We get a lot of emails from non-native English speakers asking why their posts are getting killed. This is what I usually say these days:

We understand that our non-native English speaking users are in a special position with all of this, and we sympathize - but we don't have an easy way to treat posts differently on that basis. What we're telling such users is to please write in your own voice and don't worry about any mistakes, because those are rapidly becoming signs of authenticity at this point (https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...).

To judge by how the AI classifiers react, translation tools are leaving a ton of LLM imprints on text which are not strictly about translation. As many of us have been learning, it's hard to restrict what these systems do. They are overeager on every level.

Comment by IshKebab 5 days ago

Yeah I think it's not 100% AI but my vomit senses started tingling at

> The test was deliberate.

> Step one, the safe ask

> Step two, the unfair ask

My guess "AI write a blog post about this" and then he edited it, but didn't quite eliminate the stench. Pretty close though to be fair.

Comment by abrookewood 4 days ago

You made the right call. Very interesting article and great to hear about the history of game development that isn't focussed on the US market.

Comment by khazhoux 5 days 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.

Comment by rabahs 5 days 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

Comment by sitkack 5 days ago

Tics, tropes are worn out predictable plot devices

Comment by khazhoux 4 days ago

Too late

https://tropes.fyi/

Comment by aenis 5 days 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 :-)

Comment by rabahs 5 days ago

I hear you. However I wrote that assembly code 33+ ago :) Again, I mentioned elsewhere on this post and in the article, I had to review and/or edit every line in this post. AI biggest help in writing was referencing the right source / graphics..etc. Thanks

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Comment by deterministic 3 days ago

I judge articles by the value delivered. Not the writing style. And this article is very much high value compared with the a-simple-idea-explained-with-a-wall-of-text low value/noise most HN stuff has become.

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Comment by lstodd 5 days 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.

Comment by cstrahan 5 days ago

Suppose there are two options: remaster the game with AI assistance, or don’t remaster the game at all (because that would entail porting 72,758 lines of assembly by hand, and the time-to-reward ratio would be deemed to low for most people).

Why complain about the outcome? The old game remains available, and you can play it for free. This isn’t some zero sum situation where the existence of the remastered game sets the world back in some way. I could see being more interested (or only interested) in playing the original, but I don’t see what motivates the negativity.

Comment by rabahs 5 days 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.

Comment by mickeyp 4 days ago

You don't have to apologise for anything. Your blog post, post-mortem, and detailed walked through is fantastic. This is a great use for AI.

I miss my Amiga 500 and all those days spent playing wonderful games so much. Thank you for the hit of nostalgia.

Comment by tomcam 5 days ago

You handled GP's post much better than I would have.

Comment by urbnspacecowboy 5 days 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

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