(04-21-2012, 10:55 PM)Gir Wrote: Xbox 1 use a Pentium III X86 CPU you could execute its code on a Core i7 pretty fast, i guess the DirectX of the Xbox is the problem.
If they cant emulate the Xbox1 why bother thinking about Xbox360
The developer of cxbx had said that emulating the CPU isn't as easy as most people would think:
Quote:2. Emulating an x86 CPU is a lot harder than it sounds. I don't know where this mindless assumption comes from. Yes, there's loads of documentation on how the x86 processor works, but that doesn't exactly make it easy. First of all, the x86 instruction set is M-A-S-S-I-V-E! There can be at least 20 different versions of one instruction (i.e. There are many different versions of the MOV instruction, as well as INC, DEC, ADD, SUB, SHR, SHL, AND, OR, XOR etc.) and it takes time to implement them all. Of course, that's not exactly difficult. The real problem is that any modern x86 processor including the Pentium III can execute multiple instructions at once. So it's not like emulating a Z80 doing one instruction at a time. The actual algorithm and how x86 does this is undocumented and still unknown. In short, the Xbox's CPU can be emulated, but not accurately.
There are numerous other complications, such as lack of documentation. The Xbox itself happens to be a fairly complex machine to begin with, so of course emulation's going to be difficult for those seeking to emulate the system. The 360 technically has the best Xbox emulation, but even it doesn't have 100% compatibility.