[fiskfiskfisk]

There's a pretty good list of backwards compatible 360 games that can be played on the modern Xbox consoles. Microsoft did the work in this case.

Since it's different architectures there's a bit of work involved in making sure the compatibility layer works as expected. It's a technical achievement that they've been able to do it as good as this.

There's also OG Xbox games available with a compatibility layer as well.

https://www.eurogamer.net/articles/xbox-backwards-compatibil...

[nailer]

It's actually amazing that Microsoft:

- Paid developers to emulate a Pentium III (original xbox) on a PowerPC (360) in the first place

- Subsequently paid developers to do the effective opposite - emulate PowerPC (360) on x86 (one, series)

Also consider it's far easier to emulate an original xbox on a one/series than it was on a 360

[danbolt]

I can imagine reworking the x86 processor should be straightforward, but I'd be curious about the cost of emulating the proprietary hardware inside the Original Xbox (eg: render pipeline, memory architecture, I/O, etc.).

An example of this sort of thing can be well-observed emulating the Nintendo 64. The CPU is a plain-standard MIPS III, but emulating the console's graphics chip hasn't always been accurate for a long time. Disney-released games on the Nintendo Wii would toy with the write-back cache to prevent emulators from booting their games.[1]

I can imagine the largest amounts of difficulty are outside the CPU for a polished-enough project.

[1] https://dolphin-emu.org/blog/2017/02/01/dolphin-progress-rep...

[nix23]

Yeah amazing (me playing a DOS game on a FreeBSD PowerPC machine), Thanks anyway Microsoft ;)

[bartread]

For supported games this works incredibly well, and I imagine there's probably no technical reason it couldn't be made to work for all 360 and Xbox OG games.

However, it doesn't appear to come for free in terms of effort: I don't believe there's a kind of universal emulation layer that supports every game. When you put in a game disc for a support Xbox or 360 game the console doesn't install the game direct from the disc but rather downloads a compatible version from Microsoft. The disc simply proves that you own the game (and you still have to insert it every time you want to play the game).

This has some advantages and disadvantages. The obvious advantage is that the downloaded version could include enhancements like better visuals, sound effects, bug fixes, etc., and plenty of games on the backwards compatibility list do include some level of enhancement.

The obvious disadvantage is that you can't just play any old game you might own. I don't know why Microsoft haven't implemented some sort of universal backwards compatibility directly into the consoles but obviously they have their reasons.

The fact that the games are downloaded rather than installed from disc throws up another issue: licensing. It will never be the case that all games are supported through backwards compatibility due to content licensing issues (effectively Microsoft are redistributing content because of the way compatibility works).

Similarly, some games ship with altered content due to licensing issues. One fairly well know example here is GTA: San Andreas, where the soundtrack differs quite significantly from the version on the disc. The best way to play GTA: San Andreas on a console if you want to experience it as originally intended still remains original PS2 or Xbox hardware or, if you have one that works still, earlier models of PS3 that included PS2 backwards compatibility (this was removed in later revisions).

[easton]

I think the reason is that the Xbox 360 had a PowerPC chip/architecture vs the x86 of the current Xboxes, and the developers often wrote close to the metal optimizations that may not be feel good when put through a normal emulator (if they could even get it up to speed). This way, they know it'll work perfectly and can sell the game in the Xbox Store if you have never played it. (And can stop games that will never work, like Kinect games).

[Jerrrry]

The months before rolling this out, they modified an internal API "reserve-gamertag" and introduced a small chance of a race condition.

This race condition allowed anyone spamming (3k+ req/sec) this one specific public API to eventually (2 minutes) take any unbanned inactive Xbox360 gamertag that hadn't been migrated to the XboxOne platform.

Xbox has no bug bounty program; ironically this means the finder of this exploit made 10x what Microsoft would had given him, even by a generous estimate.