The myth of software PS2 emulation on PS3

[noiseredux]

that is interesting!

But yeah I guess I just kind of figured that most collections like that would just be emulators built by the publisher. Hadn't really thought it through I guess.

[MrPopo]

The other thing with the Zelda collection is that the oldest titles in it couldn't be ported easily (compared to porting a PS2 game to PS3). They were written in NES assembly, so to port it would require essentially recreating the whole thing using GC calls. Much easier to just write an emulator (especially given the Wii VC that was upcoming). Now porting a PS2 game to the PS3, they're both written in some high level language, quite possibly C. If you coded it up decently the first time them you have the system specific stuff in one chunk and the regular math stuff in another chunk, so you'd just need to rewrite some of the graphics calls to do the port.

[noiseredux]

The other thing with the Zelda collection is that the oldest titles in it couldn't be ported easily (compared to porting a PS2 game to PS3). They were written in NES assembly, so to port it would require essentially recreating the whole thing using GC calls. Much easier to just write an emulator (especially given the Wii VC that was upcoming). Now porting a PS2 game to the PS3, they're both written in some high level language, quite possibly C. If you coded it up decently the first time them you have the system specific stuff in one chunk and the regular math stuff in another chunk, so you'd just need to rewrite some of the graphics calls to do the port.

it's obvious that you know a lot more than me here. So I guess my frustration with this whole issue is that I just don't understand -- can you give me baby terms as to why writing a PS2 emulator for the PS3 would be so difficult?

SIDEQUESTION, since you seem to be so knowledgeable here, what do you think of that rumored add-on piece of hardware that could allow PS2 BC? Is it real/possible/probable/etc?

[MrPopo]

The other thing with the Zelda collection is that the oldest titles in it couldn't be ported easily (compared to porting a PS2 game to PS3). They were written in NES assembly, so to port it would require essentially recreating the whole thing using GC calls. Much easier to just write an emulator (especially given the Wii VC that was upcoming). Now porting a PS2 game to the PS3, they're both written in some high level language, quite possibly C. If you coded it up decently the first time them you have the system specific stuff in one chunk and the regular math stuff in another chunk, so you'd just need to rewrite some of the graphics calls to do the port.

it's obvious that you know a lot more than me here. So I guess my frustration with this whole issue is that I just don't understand -- can you give me baby terms as to why writing a PS2 emulator for the PS3 would be so difficult?

SIDEQUESTION, since you seem to be so knowledgeable here, what do you think of that rumored add-on piece of hardware that could allow PS2 BC? Is it real/possible/probable/etc?

I think you can write a PS2 emulator for the PS3. You have all the necessary calls available. The trick is to write one that's fast enough. The way an emulator works is that it intercepts all the instructions that the program is sending to the old hardware and translate them into something understandable by the new hardware. However, there isn't a simple one-to-one translation for these kinds of calls. Sometimes you have an instruction that looks simple, but what it essentially does is tells a specialized processor "do some magic given these inputs". So your emulator has to recreate that magic. Plus, you have to account for things like different clock speeds between the old hardware and your new hardware. If you've ever played an old DOS game on a more modern PC just using DOS (not DOSBox) then you've probably seen the speed up effect. You can have similar problems. So it's not that they can't write a PS2 emulator. The question is whether or not they can write a fast enough emulator.

As for the rumored addon, the only way I can conceive of it working is that it would be a USB plugin where the PS3 reads from the PS2 disc, pipes that data straight to the addon (which is likely just a stripped down PS2), the addon does work, and then the data comes back over USB so that the PS3 can output it. There would also be two way communication for the disc access (the addon says to load from a certain section of the disc). I don't think the bandwidth of USB is high enough for it.