I wonder about that too. The fact that some 360 games are supported on newer consoles but not others suggests either they're doing game-specific hacks or they actually change the source code.

The 360 could also play original Xbox games without much exception, but it was noticeably slower than the original. Halo 2 on 360 has a shorter fov.

> The 360 could also play original Xbox games without much exception

I remember there being a list of what it could play but I was never too sure how comprehensive it was. I know it couldn't emulate Midtown Madness 3.

Oh. So it can't emulate the game I probably played the most.

I think the 360 backwards compatibility is a mix of emulation and certain parts being disassembled & recompiled for x86 with some black magic.

edit: Here's an interview with platform lead Bill Stillwell that goes into a lot more detail https://www.eurogamer.net/digitalfoundry-2017-xbox-one-x-bac...

Oh sweet, thanks for the link. It sounds like it was harder getting things running on the XB1's tiny CPU vs running an emulator on monster dev machines, no surprise there! :-D

I believe there is actually a recent userland project that disassembles and recompiles 360 games for x86...

Hands down my favorite thing about my time at microsoft as an intern was just a random brown bag lunch with the engineers who did the powerPC emulator for xbox360 games on xbox one. It was an incredible talk and they went deep and were happy to answer questions.

Oh damn, I was probably there at the time, working in the building, and was completely unaware of the talk!

That would've been awesome!

By that time though my org had spun out of Xbox to become the Microsoft Band team, so we didn't get any of the cool invites anymore. :(