No one able to provide decent feedback reads the Speculation forum. PLEASE don't reply with a nonsense post about how a system must be [some number here] times powerful to emulate another. One of the largest costs in emulation performance is from instruction translation (I think). That cost might be drastically reduced because of what I'm asking about. Also please don't be a post-whore and just post to see yourself speak. I've come to this site a few times with serious questions (PS2 controller adapter ideas for the PSP that are prob. pretty feasable, etc., they always vanish without serious response under worthless commentary)... I am a coder but I am too busy right now to pursue this... (as I was the other thing I spoke of)...
From my first post over there from the thread I'm talking about:
"Also, I've been wondering lately... I've heard a lot about the PSP being very similar in terms of the chips etc. to the PS2, I don't know how accurate this is, but maybe if they are very similar a PS2 emulator for the PSP would actually be easier to implement (and it might actually run games at a decent speed)?"
"Obviously I don't have a lot of insight into this, just posting it because I've been thinking about it lately. It would make sense that Sony would want the PSP to be very similar to the PS2 to facilitate porting successful PS2 games/software components and so that it would be easy for people to develop games for both platforms simultaneously. Certain apps I'm sure are not maxing out the PS2 that are for PS2... like the old Tekken arcade games that come with Tekken 5, presumably running under emulation. I want to run those puppies on my PSP, you know? Hehe."
From my second post over there from the thead I'm talking about:
"More info. I found tonight:
"MIPS instruction set architectures are backwards compatible, ie a MIPS IV processor can still run MIPS I code."
PS2 - MIPS R5900 CPU core, 64 bit, 294 MHz
PSP - MIPS R4000 CPU core, 32 bit, <= 333 Mhz
So, the PSP CPU core is actually an older model? Let me now look into that.
More PS2 info., from http://www.bringyou.to/games/PS2Basics.pdf
"MIPS R5900 CPUThe R5900 is a RISC chip based on a MIPS architecture (http://www.mips.com). It implements the full MIPS III ISA, some MIPS IV instructions, and a proprietary set of multimedia instructions. (TODO: Sure it's not a full MIPS4?)"
Let's see what instruction set architecture the PSP's R4000 CPU uses. MIPS III ISA. From http://gcc.gnu.org/onlinedocs/gcc-3...PS-Options.html
Issue instructions from level 3 of the MIPS ISA (64-bit instructions). r4000 is the default cpu-type at this ISA level."
So, at first glance, it would look like the only CPU instructions that would require translation would be those which made the PS2's R5900 CPU not a standard R5000 (see the reference to the additional multimedia instructions above -- I believe the R5900 name implies it's a variant CPU). Maybe the extra 333 MHz - 294 MHz (39 MHz) horespower of the PSP could handle the minimal instruction translation...
Obviously the CPU is only one component (of many, I realize that this is still a long shot!) of the PS2. Let's see if they have any other blatant similarities...
Both systems appear to have 32 MB of primary working RAM, although maybe the PSP OS/modules are always taking up some of this (I hope not too much, but any at all during games might prove challenging since I doubt there are many PS2 games out there that don't use nearly all of the system memory).
Emulation of the vector units is pretty much where I begin to have no clue about the feasability of this. Here's some info. semi-related:
"Unlike Sony's PlayStation 2 console, the GPU (PS2 Vector Unit equivalent) is not programmable, meaning that many effects that the PS2 can resolve in hardware must be implemented in software on the PSP."
Yikes. That would prob. be costly, especially since the graphical power of the PS2 is greater than the PS2's to begin with. So let's assume that these effects are translated on the PSP's media engine CPU (identical to it's other primary CPU according to http://us.codejunkies.com/news_revi...&p=1&i=6073&s=1) and handled by the PSP's graphics cores -- who knows what kind of performance we might see (yes, probably bad, but I'm not smart enough or experienced enough to accurately guesstimate this).
This whole business of the last quote I have above doesn't seem completely legit. The last source I listed (http://us.codejunkies.com/news_revi...&p=1&i=6073&s=1, which I admit is very old) lists that the PSP does have some sort of vector units.
Time for a conspiracy theory. I know that this is highly unlikely/prob. not possible. But can you imagine the greatness of the following business plan (which I highly doubt has any truth!)?
1. Release PSP
2. Ship relatively few quality titles for X amount of time, X being as long as it takes to get the system secured
3. Release lightweight PS2 emulator with firmware revision Y
4. Completely dominate handheld market by instantly making available on the PSP what's prob. the largest and one of the most successful back catalog of games ever -- the PS2's. PS2 games are signed (we've all come to find how well this works -- no sarcasm here) and downloaded to the PSP (funny how all of this talk is coming about Sony wanting larger memory cards or PSP/PSP2 drive attachments, eh? Why should Sony care about giving you more space for your media -- as a company they tend to not go out of their way to do favors for the consumer -- unless it benefits them).
Maybe they will come up with an emulator that somehow reduces model complexity on the fly or slightly early (I doubt it, I can't think of a way to do this, that's for sure) and renders to the PSPs native resolution.
Yeah, probably not, but it was fun to think about... admit it..."