Libgodc: Write Go Programs for Sega Dreamcast

[drpaneas]

I built a Go runtime that runs on the Sega Dreamcast, the 1999 console with 16MB RAM and a 200MHz SH4 CPU.

You can write games in Go with goroutines, channels, garbage collection, and all the language features you'd expect. It compiles using gccgo and runs on real hardware or emulators.

The project includes 3 game examples Pong, Breakout and Platformer, input handling, audio support, and integrates with KallistiOS (the Dreamcast homebrew SDK).

* Star Here: https://github.com/drpaneas/godc * Documentation: https://drpaneas.github.io/libgodc/ * Video Tutorial: https://youtu.be/ahMl0fUvzVA

Happy to answer any questions about the implementation!

[danhau]

I just wanted to say how impressive your documentation is. I expected an average readme.md, but not only is your readme great (the performance table is wonderful), but the full documentation is awesome. It pretty much answers all questions I had. Nice job! I wish all projects were like this.

I also dig the documentation / book styling.

[clktmr]

Hey panos! I only had a short look at this for now, and it looks impressive! I'll have to dust off my Dreamcast and get this running.

I looked at gccgo when porting the runtime to n64, but at the time it wasn't updated since go1.18. Can we use Go Generics on the Dreamcast? I see that gccgo is obviously needed to support SH4.

[simonw]

This is a beautiful thing to exist. Much respect for building this.

[lagniappe]

You've made my entire WEEK! Thank you!

[pjmlp]

This is kind of cool, kudos for the effort.

[phantasmish]

> Replaces the standard Go runtime with one designed for the Dreamcast's constraints: memory 16MB RAM, CPU single-core SH-4, no operating system.

24 total megabytes, with an M, of memory between system and video (another 8 there), single core 200mhz CPU, graphics chip runs at 100mhz. Shenmue runs on it.

Glares at Teams.

[pjmlp]

I really don't get how Teams gets developed, not even the worst offshoring projects I have been part of, have reached so low in quality.

[giancarlostoro]

It baffles me that Microsoft can build an entire OS, and build and rebuild GUI stacks, and they couldn't build the Teams UI using C#???

[bttf]

Would happily take work chat, video conferencing in network-enabled Shenmue over Teams, Slack any day

[perching_aix]

Could implement a custom Teams client on top of that. My biggest concern would be TLS and media decoding, but could just proxy the traffic and roll a text only client.

I mucked about with Microsoft Graph a bit before, didn't seem too bad.

[gethly]

> CPU single-core

This does not fare well for Go though.

[donatj]

The "Effective Dreamcast Go" docs on this are fantastically well written. I've read much worse docs from major corporations.

[drpaneas]

Many thanks @dontaj much appreciated, indeed documenting the process felt like another project of its own, so I am very happy to hear that! The effective dreamcast Go was inspired from the old time classic https://go.dev/doc/effective_go :D

[Imustaskforhelp]

If someone is interested in running golang projects on niche hardware perhaps, one pro tip I can suggest but there is way to convert golang 100% into wasm (no js shim or anything required) and the only thing you would need is a wasm library

You have to use golang from source (see the stackoverflow page https://stackoverflow.com/questions/76087007/golang-to-wasm-... )

go install golang.org/dl/gotip@latest gotip download GOOS=wasip1 GOARCH=wasm gotip build -o main.wasm

Although the way I did it is going into the gotip folder and then the binary folder which would contain the go compiler binary and then just use that path with

GOOS=wasip1 GOARCH=wasm ~/sdk/gotip/bin/go build -o main.wasm

Note that I forgot the exact path but it was similar to this but the point being that its super easy and simple :)

I tried to do it and I can tell you that it works and it works for even the most latest versions of golang, all you need is a wasmengine which I suppose can be ubiquitous.

I have built a solution where golang code gets converted to wasm and then we run a ssh server which then runs that wasm all in sandbox to create sandboxed mini golang servers :p I really love it although its a more so prototype than anything

[gothink]

Looks like this is available (since Go 1.21 [0]), so no need to build from source anymore. Just did a quick 'hello world' test to verify and it worked:

    GOOS=wasip1 GOARCH=wasm go build -o main.wasm main.go
    wasmtime main.wasm

If you're interested in wasm/wasi and niche hardware with Go, you should check out TinyGo [1] if you haven't already.

[0] https://go.dev/blog/wasi

[1] https://tinygo.org/docs/guides/webassembly/wasi/

[nasretdinov]

Nice project! Having just 16Mb of RAM does indeed sound like a real challenge for stock Go (not the TinyGo variant)! Even hello world is a couple megs, although I imagine Dreamcast isn't 64-bit, so the instructions are probably much shorter. Interesting to see anything written in it :)

[drpaneas]

Thanks :D How about porting Diablo? https://x.com/PanosGeorgiadis/status/2005692695402955143

[AdmiralAsshat]

> Who is this for? > ... > Anyone who enjoys the challenge of severe constraints

Remembering what a powerhouse the Dreamcast was when it came out, and how amazing games like Soul Caliber and Shenmue looked, it's hard to think of the Dreamcast hardware as "severely contained".

[jerf]

I find it a bit weird that I find it intuitive how things like the Super Nintendo did their work, and how modern games and systems work, but comparing the hardware specs of the Dreamcast/PS2/XBox/Gamecube era to the best of their output is where my intuition struggles the most. Not that the games of the era stand up to modern stuff, even when upscaled and texture-packed etc. in an emulator, but how they did it with so little oomph still amazes me.

[drpaneas]

yeah, been there, nostalgia hits hard. Dreamcast was a beast of its era, it even had Ethernet! Even the VMU was something extraordinary! Too bad SEGA had to cancel it :(

[RestartKernel]

This is incredibly cool! How do you think these modern language features would have affected Dreamcast development back in the day? (I have no idea of how difficult the console was to develop.)

[aj_hackman]

It was a dream relative to anything else on the market (until 2001, when the Xbox and GameCube were released), made even easier for some titles due to the optional Windows CE SDK. You still needed to do a fair bit of SuperH assembly programming to get reasonable graphics performance, but it was nothing like the nightmarish complexity of the PS2, despite having half the RAM. It's still one of the more popular homebrew targets.

[drpaneas]

I think Lua (yes you can code Dreamcast games with it) would be really awesome for kids, being able to make their own games, given the language is simple, like Python. But in general, for serious stuff C/C++ is still the preferred way.

[XajniN]

This is awesome, but it’s even more amazing that it even exists. How many people actually make software for Dreamcast? Why?

[rpastuszak]

I love this. The documentation is great and I've even learned a thing or two about golang from it! The logo makes me want to port Icy Tower to DC.

[drpaneas]

thanks @rpastuszak, much appreciated :D

[karel-3d]

I thought that gccgo supports only some old go version? Or subset of features? I will need to refresh my memory for sure

[drpaneas]

I am using sh-elf-gccgo (GCC) 15.1.0 which is ok-ish I guess. But in general gccgo tries to be close to Go, but they do not implement all the features. e.g. generics are still missing for example.

[tasa1969]

amazing work! The "book" documentation is better than most of the books I have read and paid this year! Kudos!

[drpaneas]

glad to hear that tasa

[kostas73]

Great stuff!

[drpaneas]

Thanks Kosta <3

[steeve]

this is incredible

[drpaneas]

thanks @steeve :D