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."
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.
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."
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.
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.
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.
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..
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.