Nes emulator written in go

by netbun • 11 years ago

108 55 11 years ago

sfeng• 11 years ago

Take a look at the code if you haven't: https://github.com/fogleman/nes/tree/master/nes

I don't know if it's a statement about fogleman or Go, but it seems so much more clean than other emulators I've looked at.

jmgrosen• 11 years ago

See also sprocketnes, an NES emulator written in Rust: https://github.com/pcwalton/sprocketnes

It was written by pcwalton, one of the main driving forces behind Rust. (Unfortunately, it hasn't been updated for a couple months, so it won't build with latest rust).

kibwen8• 11 years ago

NES emulators are a common and fun challenge for testing out languages. Here's one in Clojure that intends to be fully immutable, such that you can rewind and fast-forward through history at will: https://github.com/samfoo/clones

In the case of Sprocketnes, one of its goals is to serve as a demonstration of Rust's ability to run entirely without a runtime (see the long-outdated quote in the readme: "The Rust garbage collector is not used in this project"... we really need to get this updated for 1.0).

MetaCosm6• 11 years ago

It was written by pcwalton, one of the main driving forces behind Rust. (Unfortunately, it hasn't been updated for a couple months, so it won't build with latest rust).

Possibly the most telling sentence I have ever read about Rust. I am (well more honestly, was) excited by the language but until there is some sort of stability guarantee, it is a fun toy, a distraction.

The Rust community appears desperate to have continuous improvement at the core language level, and despite some hand-waving, it feels like they simply won't be pinned down. I will watch it with interested post the May 15th 1.0 deadline -- but since they shipped entirely new Path and IO in Feb -- added new language constructs and removed others (Alpha2)... I am worried...

4ydx• 11 years ago

The last time I checked this is a link about go? Or no?

shurcooL4• 11 years ago

If I may be so bolt to plug my tool, but would http://gotools.org/github.com/fogleman/nes/nes be a nicer way to look at the source of the entire Go package?

shurcooL4• 11 years ago

*bold, sorry about the typo.

hahainternet• 11 years ago

Line numbers should be linkable in the same way as a filename is. Perhaps they should be foldable.

oneeyedpigeon• 11 years ago

If you must force a target on links to other packages, can you at least use a static name (rather than _blank) so the same package doesn't keep opening in different tabs? E.g.

    <a href="/errors" target="errors">"errors"</a>

fogleman2• 11 years ago

Looks pretty good.

hello_moto5• 11 years ago

Where can I find newbie resources (books, or anything) to write NES (and potentially SEGA and SNES) emulator?

I wouldn't mind if I have to learn from zero (OS, hardware, etc). I think I might have found a side project that I can be passionate about!

UPDATE: Thanks for the replies. I'm having hard time to follow those links since I don't even know where to start. Is there another tutorial that can explain the fundamental of "emulator" first before the NES part kicks in?

PS: I'm planning to use Java for this side-project.

mjibson• 11 years ago

http://nesdev.com/

Is a fantastic resource. They are helpful and have lots of docs.

benbruscella• 11 years ago

Zophar's would be a good place to start

http://www.zophar.net/utilities/nesdev.html

astrange2• 11 years ago

You can read the source to existing projects (bsnes, SNES9X, gambatte etc.) The Gameboy would probably be the simplest hardware to work on.

PS: I'm planning to use Java for this side-project.

Emulators typically use repetitive code, less than int-sized math, 2d arrays and pointer manipulation. Java is not good at dealing with any of those, so you might want to find a more fun language. Then again, one thing at a time.

hello_moto5• 11 years ago

Exactly, one thing at a time. Once I get a good grasp and managed to deliver a working emulator, then I can start thinking about improving/optimize or even port it to another language.

Right now I'm just trying to figure out the basic fundamental concept of "emulation" (what is it, what does it take, how can I write a simple one :)).

edmccard• 11 years ago

Is there another tutorial that can explain the fundamental of "emulator" first before the NES part kicks in?
PS: I'm planning to use Java for this side-project.

One place to start might be to try and write an emulator for the DCPU-16. It's a simple made-up computer that Notch (creator of Minecraft) designed for the game 0x10c.

Although the game was never finished, many people wrote emulators based on the DCPU's specifications[1]; search Github for "DCPU Java" to see several examples in that language.

[1] https://raw.githubusercontent.com/gatesphere/demi-16/master/...

gatesphere• 11 years ago

Hah! That's my repo!

Also, the only emulator for anything written in Io, as far as I know :p

Not that it was good, mind you. But I do highly recommend DCPU-16 as an emulation launching point. It's a really easy to understand system :)

hello_moto5• 11 years ago

Thanks a lot for pointing me at this. While NES is the goal, I definitely need to take baby steps first!

Spittie• 11 years ago

The usual place to start to start an emulator is the CHIP-8 (https://en.wikipedia.org/wiki/CHIP-8), because it's a very easy platform that don't have a lot of the "complicated" stuff that's in more complex hardware.

The overall logic is very simple (read a program into ram, read an opcode from the starting location, do whatever that opcode is supposed to do, go to the next opcode... rinse and repeat) and you can find tons of tutorial online (I liked this one: http://www.multigesture.net/articles/how-to-write-an-emulato...)

It should set your mind on the fact that writing a simple emulator is just doing a fetch/decode/execute (https://en.wikipedia.org/wiki/Instruction_cycle) on some code.

For the documentation, I've found that EmuTalk (www.emutalk.net/forums/30-Emulator-Programming) has tons of interesting links.

hello_moto5• 11 years ago

Thank you very much!!!!

tibbon• 11 years ago

While not NES, one of my students at General Assembly made a Chip-8 emulator/interpreter in JavaScript for their final project.

Chip-8 has 30-something instructions and is relatively simple to implement, and test driving it is pretty easy too. I thought it was a really wonderful first emulation exercise.

http://en.wikipedia.org/wiki/CHIP-8

fogleman2• 11 years ago

This PDF gives a good high level overview of the NES: http://nesdev.com/NESDoc.pdf

hello_moto5• 11 years ago

Thanks a lot! I really appreciate this!

atesti• 11 years ago

Here's a very clean and clever NES emulator in C++ by Bisqwit of TAS fame: https://www.youtube.com/watch?v=y71lli8MS8s

He presents the code in the style of a tool assisted run, typing it in in high speed. I never saw templates used like that to create the unrolled CPU dispatcher

kibwen8• 11 years ago

The code for the CPU dispatcher begins at 1:26 in the linked video, for those not willing to watch the whole thing.

A comment elsewhere in the thread mentions Sprocketnes, written in Rust, which takes a different tack here: it uses a hygienic macro to implement opcode dispatching, which allows the giant block of dispatching logic to be reused for both the emulator and the disassembler: https://github.com/pcwalton/sprocketnes/blob/master/cpu.rs#L...

dtech• 11 years ago

Another ${things that exists} in ${current trendy programming language} submission, why does this get upvoted?

ncza• 11 years ago

Because programming is fun, new languages too and hacking is what this site is about.

le_lenny_face• 11 years ago

Because this is Hacker News.

Because doing ${things that exists} in ${current trendy programming language} is somehow gauged as a Good Thing™ in your portfolio by the startup mindset.

Because posting this Good Thing™ on Hacker News is basically the SF startup scene's own LinkedIn equivalent.

Because other people who has bee doing this Good Thing™ want their own Good Things™ to be validated as well, so they continue this tradition.

alenmilk• 11 years ago

Because Conservatives are always on the wrong side of history. And new things replace the old, and there is a reason C is the biggest language of them all.

dagw• 11 years ago

Because comparing the same thing done the 'new' way and the 'old' way is one of the best ways to see the differences between the two ways and find out if and when the new way is better.

0xdeadbeefbabe• 11 years ago

I take it as a sign of intelligent life in an otherwise web dominated world.

BasDirks• 11 years ago

Look at how deeply nested the code is. Hint: it isn't. Super clean code.

nwidger• 11 years ago

I also wrote an NES emulator in Go https://github.com/nwidger/nintengo

AaronM• 11 years ago

This one is very easy to read. I wish the emulator I am working on was this clean. Looks like I may need to do some refactoring!

anonbanker• 11 years ago

Thanks for posting the SMB3 screenshot. now I know how (in)accurate the emulator is.

for those that don't know, the title screen, above the checkerboard, has a very thick black line. compare to a proper NES (or Nestopia) to see.

Nes emulator written in go

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