[adamrezich]

It's not that they're porting over games individually, it's that they have to get express permission from the publisher of each individual game. Something about the terms of the contract between the publishers and Microsoft being such that a user is only able to play the game on that specific platform (Xbox 360) unless the publisher says otherwise. One could somewhat cynically look at this and say that this is because publishers love to rerelease games for the new platforms; already we've seen a bunch of rereleases and "HD Editions" (even though last generation was also HD) for the PS4 and Xbox One.

[dogma1138]

Hmm sorry but they are porting games, once you insert the disk your Xbox One will download a huge chunk of data of the internet were talking 5GB+ for each game.

Microsoft also isn't hiding it: "The digital titles that you own and are part of the Back Compat game catalog will automatically show up in the “Ready to Install” section on your Xbox One. For disc-based games that are a part of the Back Compat game catalog, simply insert the disc and the console will begin downloading the game to your hard drive. After the game has finished downloading, you will still need to keep the game disc in the drive to play."

http://www.xbox.com/en-US/xbox-one/backward-compatibility

Sure they might be downloading the 360 version and then doing the emulation but it's much much more likely that they've actually simply ported the game.

[UberMouse]

They are not porting, they have built an emulator that runs the 360 OS and then they boot the games inside of that.

>Delving deeper, Spencer explained exactly how the emulator packages the Xbox 360 games, and how it compares to Xbox 360's emulation of original Xbox games.

>"You download a kind of manifest of wrapper for the 360 game, so we can say 'hey, this is actually Banjo, or this is Mass Effect. The emulator runs exactly the same for all the games.

">I was around when we did the original Xbox [backwards compatibility] for Xbox 360 where we had a shim for every game and it just didn't scale very well. This is actually the same emulator running for all of the games. Different games do different things, as we're rolling them out we'll say 'oh maybe we have to tweak the emulator.' But in the end, the emulator is emulating the 360, so it's for everybody."

>Asked about whether Microsoft would require permission from game publishers to adjust game code, Spencer clarified it would not be interfering with code.

>"The bits are not touched," he said. "There's some caveats, and as always I like to be as transparent as I can be on this: Kinect games won't work from the 360, because translating between the Kinect sensors is almost impossible."

http://www.gamespot.com/articles/revealed-how-xbox-one-can-p...

I also remember watching a video where they talked about it, it had some more details. I can't remember what it's called though and I couldn't find it with a cursory search.

[jayrox]

they are not porting. microsoft has explicitly said they are emulating.

"We have to do packaging and validation work on each title to make it available through Xbox One backward compatibility," explains a Microsoft spokesperson.

Xbox One Backward Compatibility is an Xbox 360 emulator that runs on Xbox One and is used to play Xbox 360 games," says a Microsoft spokesperson in a statement to The Verge.

http://www.theverge.com/2015/6/15/8785955/microsoft-xbox-one...

[rasz_pl]

they LIED, not the first time, not even the first time this month

[voltagex_]

If they have ported the game they've also ported a large part of the 360 dashboard - chat and the guide button look pretty much identical. The early info coming out around E3 seemed to suggest full system emulation.

[dogma1138]

Why then do you have to download every game even if you have the disk?

[jayrox]

Because it comes with the emulator, compatibility modules and anything else specifically the game may need to be able to run in the emulator.

[dogma1138]

That's weird because the 360 emulation played it from the disk just fine ;)

It downloads the entire game for each disk game you put in, seems to me that the could've found a more efficient way to actually do that since you know both the 360 and the XboxOne support installing games from disk so they got the ability to create a disk image.

If all they needed to download is an emulator and a compatibility config file that would've been a much smaller download package..

[bitmapbrother]

This is incorrect. Although, they do need to get permission from the original publisher, they are porting the games. How can you tell? Just have a look at the filename of the file downloaded. It has x64 attached to it.

[jayrox]

this is incorrect. according to microsoft they are running emulation.

Behind the scenes, Microsoft has built a full Xbox 360 emulator for its Xbox One console. "Xbox One Backward Compatibility is an Xbox 360 emulator that runs on Xbox One and is used to play Xbox 360 games," says a Microsoft spokesperson in a statement to The Verge.

http://www.theverge.com/2015/6/15/8785955/microsoft-xbox-one...

the package they are sending when you insert the disc is a container that contains the xbox emulator, any media assets, the game and compatibility stuff that is needed.

[nitrogen]

You keep quoting that same Verge quote of a spokesman. Do you have a more technical or independent source? Spokespeople are rarely accurate on a technical level.

[izacus]

Do you have any source that they're actually recompiling everything?

For example running original Xbox games on Xbox 360 also required a download of a binary which was an emulation / compatibility wrapper around the binary on the DVD that shimmed out and hotpatched code so the games worked properly.

[nitrogen]

The download sizes reported by other commenters seem to suggest a bit more than simple shims.

[chc]

The download sizes do suggest you're downloading a whole game, or at least most of one. This does not, however, imply that the game is ported -- just that they pull the game from the server rather than the disc. This makes sense even if they're emulating, because most Xbox 360 games will have received a lot of updates compared to what's on the disc, and Microsoft have probably only tested the emulation against one specific version.