E3 2015: Xbox One backwards compatibility explained

Exactly how will Xbox One be able to run Xbox 360 games, especially when it was such a contentious idea just a few years ago? Shacknews visited with Microsoft during E3 2015 to find out.

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For years, there's been a hesitation to trade in previous generation consoles, since the next generation would not support backwards compatibility. The folks at Microsoft have heard the outcry from fans, so the company began looking into how to make this idea possible, a tall task given that the Xbox One and Xbox 360 are essentially built on different architecture. Now it appears that a breakthrough is at hand, with Microsoft announcing on Monday that a future Xbox One update will enable backwards compatibility with most Xbox 360 games. Shacknews endeavored to find out how this process would work.

As some may have surmised, the solution is in software emulation. The Xbox One will get the ability to emulate any Xbox 360 software and run it with the Xbox One hardware. In order to do so, users will need to jump online to download the necessary packaging pieces and essentially run through an installation process. Think of it as a mandatory install, just as with any other Xbox One game, so users will want to retain hard drive space.

The install process will allow Xbox 360 discs to be usable on Xbox One. As for digital games, those will sync to the user's library automatically, where they can simply be downloaded and installed. Theoretically, all Xbox 360 games are capable of working on Xbox One, but individual game support will ultimately depend on a title's publisher.

While this may sound like something of a cumbersome process, software emulation has its advantages. The biggest one of which is that it completely opens the door for Xbox 360 games to utilize certain Xbox One features. Features like snap, in-game screenshots, taking game clips, and sharing are fully supported for Xbox 360 games. The Xbox One button will function for Xbox 360 games as it would anywhere else, returning players to the home screen. Certain Xbox 360 functions will also be retained, most notably the Xbox Guide, which can be accessed by holding down the View and Menu buttons. In fact, players using an Xbox 360 game on Xbox One will be able to play online with friends using that same game on their Xbox 360.

The last thing to note is that this is backwards compatibility for software only. So while a game like Rock Band 3 or Guitar Hero World Tour would certainly be playable on an Xbox One, the instruments will not be supported. Sorry, music game fans.

Microsoft is aiming for the holiday season to deploy the backwards compatability update, but members of the Xbox One Preview program can take advantage of this feature right now.

Senior Editor

Ozzie has been playing video games since picking up his first NES controller at age 5. He has been into games ever since, only briefly stepping away during his college years. But he was pulled back in after spending years in QA circles for both THQ and Activision, mostly spending time helping to push forward the Guitar Hero series at its peak. Ozzie has become a big fan of platformers, puzzle games, shooters, and RPGs, just to name a few genres, but he’s also a huge sucker for anything with a good, compelling narrative behind it. Because what are video games if you can't enjoy a good story with a fresh Cherry Coke?

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  • reply
    June 18, 2015 6:00 AM

    Ozzie Mejia posted a new article, E3 2015: Xbox One backwards compatibility explained

    • reply
      June 18, 2015 6:25 AM

      It's interesting that I keep hearing it called emulation, but in the GB interview Phil Spencer said it was a VM of the 360 running on the Xbone. I wonder if it's just marketing speak because they know that emulation is the term people will probably understand. I want more technical details. Hopefully they will be forthcoming with them in the future.

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        June 18, 2015 6:38 AM

        [deleted]

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        June 18, 2015 6:43 AM

        They've GOT to be doing some sort of recompilation I have no fucking idea, that sounded good though

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          June 18, 2015 6:47 AM

          I don't think so. When you launch a title it launches a 360 VM that shows the 360 boot screen then jumps you right into the game. Complete with the 360 style Xbox toasts and everything.

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            June 18, 2015 6:52 AM

            Yeah but nobody has done PPC -> x86 on the fly translation well yet

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              June 18, 2015 10:42 AM

              Rosetta was decent; certainly had its flaws but worked more often than now.

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        June 18, 2015 7:05 AM

        honestly i think you can figure out most of the details yourself. dollars to donuts, it will turn out to be pretty much the same as Apple's Rosetta, which allowed OSX PPC applications to be run on an Intel OSX system without needing the original developer to do anything. this is how a Rosetta-style system works:

        - they translate the compiled code from the PPC ISA to x86 directly. it's not recompiling -- I don't think microsoft expects every xbox 360 publisher to send them the full source code to all of their xbox 360 games. this is a solved problem; Rosetta demonstrated that this is complete possible and works great. you only have to translate the game code, not any of the libraries that it calls, because...

        - they aren't translating the xbox 360 system code itself. they have the source code for this, so they port it to run natively on the xbox one and use the xbox one hardware. this includes the blade interface and other xbox 360 subsystems.

        - system calls in the original PPC code are rerouted by the translator to the new native libraries, which have the same APIs available.

        - this newly produced x86 game, translated from the original PPC game, then runs under a virtual machine which contains the translated game and the ported 360 libraries and subsystems and the 360 blade interface.

        thus the only part running under instruction translation is the game code itself. as soon as the game calls into the system, you're back into native territory. thus performance should be fine, because it's not emulating a PPC chip. it's translating the game's specific PPC code to x86 and then running it. it's possible they're even doing the translation offline and then shipping the result as a download rather than having the XB1 itself do the translation.

        i would be shocked if it worked differently than this, because how else could it work?

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          June 18, 2015 8:18 AM

          Looks like there might be a slight performance increase at least in this Mass Effect comparison video:

          https://www.youtube.com/watch?v=kjblk1ADq9k

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            June 18, 2015 8:20 AM

            the xb1 is way faster than the 360 and the translation should have minimal performance impact, so i'm not surprised. short of actually shipping the 360 hardware inside the XB1, this is pretty much the best way to implement BC. it should work really well

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            June 18, 2015 8:21 AM

            I really can't wait to play Lost Odyssey again.

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              June 18, 2015 8:26 AM

              f that. Shadow Complex here I come!

              I knew I should have kept that save :(

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                June 18, 2015 8:54 AM

                Luckily I have all my 360 save games still. Need to get them moved from the 360 they are on to the cloud though.

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                  June 18, 2015 8:58 AM

                  thinking about it I might actually still have them. I'll have to pull out the 360 I didnt trade in and check. But I dont think I wiped that one. Need to find my old VGA cable for it.

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                    June 18, 2015 9:12 AM

                    If you can't I still have a component block for them that you can borrow. Had to get a new elite for the kids because the old one wouldn't eject the cd tray anymore and the front usb ports were all fucked up.

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              June 18, 2015 8:54 AM

              Isn't Lost Odyssey multi-disc? I think they're still working on how to implement multi-disc titles.

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              June 18, 2015 9:45 AM

              I haven't seen it (or Blue Dragon, or Tales of Vesperia) on any of the list of current or upcoming BC games.

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      June 18, 2015 6:56 PM

      Will x-box one users have access to purchase the games from the ms store if they don't own them already?

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