PS2 Emulation Under PSP (Yes, seriously...)?

[AkumaATR]

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)?"

and

"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

"-mips3
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..."

[AkumaATR]

ps1 emulation is completely realistic i think btw for the same reasons... i think that guy's emulator or others are going to see decent framerates as soon as more people start pursuing this more

[streak]

I seriously doubt we will ever have PS2 emulation on a PSP, maybe PS2P but no way on the PSP we can't even get N64 to run on the PSP at 10FPS.

[danzel]

Originally Posted by UberNoob

PS2 - MIPS R5900 CPU core, 64 bit, 294 MHz
PSP - MIPS R4000 CPU core, 32 bit, <= 333 Mhz

Theres the first problem right there.
You have 64bit instructions on the PS2, that means a single instruction is 64bits big.
PSP has 32bit instructions.
You can't translate the PS2s instruction set down this much (into single instructions atleast), so you are going to definately need more cpu power on the psp.
Yes I know this argument is potentially wrong if the PS2 doesn't actually use its 64bits worth of instructions, im certain it does though.
The PS2 also has multiple processors that need to be synchronized, emulating this is cpu intensive.

Originally Posted by UberNoob

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).

This is a huge problem, generally on psp you only have 24MB of memory to work with. You have to store your emulators code in memory somewhere too, so you are going to have even less memory.

Is this possible?
Yeah, you might be able to get one or two homebrew ps2 demos running on the psp, but you won't ever get a proper ps2 emulator on psp ever.

Originally Posted by UberNoob

ps1 emulation is completely realistic i think btw for the same reasons

Correct-ish.
Having about 10times as much cpu speed and 10 times as much memory helps a bit too

[enterman]

Originally Posted by streak

I seriously doubt we will ever have PS2 emulation on a PSP, maybe PS2P but no way on the PSP we can't even get N64 to run on the PSP at 10FPS.

PS2P
PS2P Homepage

[Cronos1388]

Originally Posted by enterman

PS2P
PS2P Homepage

That is cool. If you mass produce and make them affordable i would totally buy one.


I think the problem with N64 emulation is that we don't know how to use Virtual Memory so we have to put the entire game into RAM and run it from there. With a CD system the game runs from the folder so it's not a problem. When you have a small GBA, SNES, NES, and Genesis it's not a big deal either since the games are smaller.

I just want to say not only can we not get perfect PS1 or N64 emulation but we can't even get perfect SNEs emulation. PS2 is not really feasible at the moment. Maybe if we had full access to every aspect of the PSP that SONY devs have we could make a low scale one that runs some of the older games.


Since you seem to be interested in porting systems over. I don't know there specs but if you could somehow port a Dreamcast emulator you would be my god.

[AkumaATR]

cool thanks for the replies. i never even thought for a moment that the ps2 had 64-bit instructions... even though i did mention it was a 64-bit core (unless that info. is wrong). the ps2 really was a friggin' beast, if you consider its lifespan and the fact that it is still making visually compelling/competitive games today... it's simply amazing

[AkumaATR]

Originally Posted by Cronos1388

Since you seem to be interested in porting systems over. I don't know there specs but if you could somehow port a Dreamcast emulator you would be my god.

Honestly I think those are still poor (Dreamcast emulators) even on the PC. Doesn't it use some custom Hitachi chipset or something? I forgot. Either way I think the gap between the tech. of a Dreamcast and a PSP make it near the bottom of the likeliness list (even less likely than a PS2 emulator considering what we've been discussing).

In response to the SNES stuff... I dunno. I don't know why it's not perfect yet. It's not that it can't be... it most certainly can be IMO... not sure what their hurdles are...

[AkumaATR]

Originally Posted by Cronos1388

I think the problem with N64 emulation is that we don't know how to use Virtual Memory

We could implement a virtual memory subsytem on the memory card but it would prob. perform awfully bad. But you are right about cards, fast access over the entire memory-mapped area of the ROM... cd systems def. do things differently.

[Cronos1388]

Originally Posted by UberNoob

We could implement a virtual memory subsytem on the memory card but it would prob. perform awfully bad. But you are right about cards, fast access over the entire memory-mapped area of the ROM... cd systems def. do things differently.

I thought that we didn't know how to use virtual memory at all. Like we just don't know how to stream it from the memory stick and thats why the GBA emulator is having so much trouble with playing files over 16 mb.

[Kotsos]

Originally Posted by enterman

PS2P
PS2P Homepage

I prefer the heckendorn ps2 portable much better I should say:

http://www.benheck.com/Games/Sony_pr...p/PS2p%201.htm

[Angelus3K]

NO NO AND NO!!!

How can the PSP emulate the PS2 EE (Emotion Engine) let alone the PS2 processor.

This is why n00bs need to go and.... do something else rather that ask stupid questions!

[AkumaATR]

this n00b accomplished something on the psp a while back you could only dream of... actually you couldn't even understand it enough to dream about it... sorry

i'd rather try for something until insurmountable hurdles are determined then run around screaming that something can't be done, just how i am

[Trigun]

yeah if you did something so cool then why don't you tell us mister uber n00b

[AkumaATR]

nah, i have my reasons for keeping my mouth shut to some degree

[Trigun]

because you really didn't DO anything at all

[AkumaATR]

e x a c t l y. :icon_smil

[mstrhelix]

PS2 emu will not run on PSP.

[tave]

If we cant do n64 or even ps1 then how the fsck doo you expect to do ps2

[Trigun]

hell if we can't get a decent gba emu how in the freaking hell would we get a ps2 emu?

[cwirsing]

The hardware settings are alike so itmay be possible. But i am not a dev and i do not know if it is possible.

[AkumaATR]

I was merely brainstorming guys. I am very excited about PS1 emulation possibilities now though...

[nexis2600]

ps1 is ungodly posible if properly writen (its a 32bit mips cpu with no floating point). GBA emu is just a straight port of Visual boy advance. My god my n64 emu runs demo's faster then it.

If I did a straight port of mupen64 or pj64. You can bet your ass the demo's i am running now would be much slower. Hell Nincest that I ported (which is less complex then monkey64 now) only did n64 stars (incorrectly) at 1.5fps. I now get 5.5-7.5fps on n64 stars.

What am I trying to prove? A straight port of a pc emu will result in poor emulation speeds since its not well optimised (on a p4 1ghz pc, who cares about optimising that much).

Anyays ps2 is just too far out of reach. The most you could except is running an extreamly simplified demo that only uses the cpu and nothing else.

[Trigun]

w0w you know nexis that actually makes ALOT of sense!

[Anon]

Sounds interesting, I really want PS1 Emu, since I want the Tenchu games on my PSP. The PS2 never interested me. Are the PS1 specs similar to the PSP's at all? The PS3 however *drools* Location Free, SPEX!!