Xbox backwards comparability emu question

[SquirlKiller]

I remember bungie (creators of Halo series) said that when you play Halo 2 on a 360, it applies 4x MSAA to it and upscales it nicely, which makes it look better than OG xbox (which it does). My question is, since each game has an emulation profile, does that mean different levels of anti aliasing are applied to a different game depending on the speed they run at? (or none at all?)

Also, i found that if an orig. xbox game is 720p native, the 360 emulates the 720p mode when set at 720p or higher, and applies no anti aliasing.

[professor_jonny]

i think that was rockstar with the gta game on the xbox that said that?

some games use different profiles as they are based off different game engines.
certain engines use certain tequinues to do stuff so they optimise the emulation to make the games run better as simular games use simular engines and repititive code.

it was a way of grouping them to make it an easier job of making them work with out making optimised profiles for all games or one big cycle exzact emulation.

from what i have read if you use an xbox game in a hd mode on the 360 the console up scales to native resolution but cant proform frame rate conversion from the original game and applys a 4x multi-sample anti-aliasing filter but because of this they can take a frame rate hit at times.

some games wont work in specific screen modes as the original game does not sync with the xbox360.
ie top spin only works in pal 50 and no vga etc....

[SquirlKiller]

It was bungie http://www.bungie.net/news/content.aspx ... s&cid=7139

I always thought since it was software emulation, it only relied on the CPU to process and render everything much like several emulators for PC and xbox. I thought this because on the surreal64 emu for xbox, you can run it in 720p and have 4x AA and still have it running at the same speed it ran in without 720p or AA.

What strikes me odd is when comparing True Crime: Streets of LA on the orig xbox and xbo 360 emulation, the orig xbox had a little bit low framerate when shooting while aiming (in native 720p), but the 360 has smooth/no drop framerate which is better(also in native 720p). However, in driving, the 360 frameskips alot of frames and the orig. xbox is mostly smooth.

Its a shame MS stopped releasing emulation profiles, I would love to play Def Jam FFNY and Metal Gear Solid on the 360. Metal Gear Solid 2 runs fine on the 360 with the hacked xbox emulator according to one user. IMO they should just "unlock" the emulator to play unsupported games, while keeping the already made profiles

[professor_jonny]

IMO they should just "unlock" the emulator to play unsupported games, while keeping the already made profiles

you can do this your self if you patch the title id of the game to another game on the compatibility list you can make some of them run manually.

there was a front end for the hacked emulator that was never releaced into circulation that allowed you to set the profile and the authour killed it after someone leaked the hacked files against his wishes.

a new zealand dude made the hacked files he was also the authour of the 360 shortcut maker tool.

eg if you patch the title id of nba live 2k3 with the halo title id you can make the game run (but it is slow).

i think there is 9 profiles with the nov 2007 hacked devkit files and if you patch it with a title id of another game the game may run better or worse, the problem is there is no way to tell which game uses whitch profile unless you have a devkit with the access to the protected memory to see what emulation code is loaded in ram.

with the advent of team xecuter fusion it is possible that you could do this with a retail console and dump it to debug and find out what game uses what profile then you could try each profile for best results on a piticular game ?

at the end of the day it is just easier to play them on the old xbox and have no issuies .

[professor_jonny]

I always thought since it was software emulation, it only relied on the CPU to process and render everything much like several emulators for PC and xbox.

i really dont know how it all works but it is not that simple the actual 360 software/os runs in a own sort of emulation profile with a hardware offoad controlled by the hypovioser so in reguards to the xbox emulation it is sort of emulation with in emulation but not really.

the xbox and ps3 are really a techinical fusion of software and hardware to make them work.

i guess every thing has to sync up and being thet the processors have different achetures (x86/ppc) instructions on one that take only cycle on the x86 may take several cycles on the 360 as a instruction to do that task may not be in the ppc processor and may have to do several things to do the same task.

this is just hpoththetical but in assembler the instruction move in the x86 wil move a value from one place to another in one cycle ie:

MOV X, Y

but

in the ppc it might require you to shift the vaule x in to a cpu register before it is moved into its location in a second step taking two cycles:

MOV x, register
MOV register, y

when it comes to the mmx instructions in the x86 they can do several things in paralell in one or two cycles and in the other processor may take 20 cycles to do the same thing.