PSPSOne (Playstation Emulator for PSP) WIP Update

[wraggster]

PacManFan posted this update concerning his Playstation Emulator for PSP Project.

<blockquote>Hey eveyone,

I want to let you all know the current status of PSPSOne. After I got my dyanmic recompiler(mostly) working, I realized that I just wasn't seein the speed increase I was hoping for. The actual CPU emulation was running 3-5X faster, but the screen updates were still very slow (2-4 fps).

Well, I took the plunge, and converted my project to use the latest version of the PSPSDK, and the HW accelerated graphic functions (ge functions). With this, there is good and bad news. The bad news is that I'll no longer be able to run my project under the PSPE emulator, the good news is now PSPOne has the ability to run much faster with ge functions,than with the previous SW-based rendering.

I found an open-source OpenGL graphics plugin for PCSX, and converted it to work with the PSP GL framework. The PSP GL functions take advantage of HW-based acceleration, instead of software based rendering that I was doing before.

I was amazed by the speed improvement immediatley. I am now getting 8-10fps, and that is running with the interpreted (not dynamically recompiled) version of the CPU core.

So, In short, PSPSOne is now running at 8-10fps using hardware accelerated functions through OpenGL.

Because the PSP OpenGL port is not 100% complete. My rendering has some issues. Most noticably, the textures are not in the correct format. I'm working today to manually change the code that specifies the texture pixel format.

I'm very excited by this huge jump in speed. This will be even faster once I work out some issues with my dynamic recompiler running on the PSP with OpenGL

-PMF</blockquote>

[danknugz]

woohoo! finally!~ this is what ive been waitng for, a huge library of games to play! may i say again, WOOHOO!
so, uh, where can i get it?
that was the one thing the gp2x has ( suposedly....) that psp lacked! i cant wait till i can try it out!
thanks guys!

[r00t]

WOW! Can't wait till this gets closer to release on the GPX or PSP :D Thanks for the excellent news, Good work Dev's!

[ace 18]

its almost here!!!!!!! YAY!!! keep the updates coming and of course the release!!!! And good job on this project i give you props for this great emulation..! ^.^

[Psphreak]

Nice! Can't wait to play the SF 2 port on my psp

[bottlecap]

wooo! i really really cant wait for this! actually, i can and will because i'm sure its a ton of work.

wraggster, you said it was posted, but where? where is the link??? i have some questions i want to ask him!

[geise69]

The best news for emulators I've heard in months...MONTHS! I just love when news just comes out of nowhere. Especially like this. This would be very fun to mess around with even with the speed limitation at the moment.

[PsPmAsTeR]

Hi,

What I meant was than PS1 is really easier to emulate.
To my understanding, it is just a "digital sample player" : or it plays the sounds from the CD,
or it plays audio sample directly to the DAC.
So it is FAR EASIER and less costly to emulate the sound of the PS1 than the Snes.

Now when it comes to the ps1 cpu... SURPRISE : A MIPS CPU TOO.
Which means that basically if you a program access the working ram, it just need a remapping of the code : no emulation to do.
Of course access to adress must "filtered" somehow by the emulator.
Basically a kind of hybrid between a cpu emulation and a JIT.(just in time compiler)

Theorytically, I would believe that the 33Mhz CPU of the PS1 could be emulated with only two or three time the CPU clock.
Which would basically mean as an example, that the ME chipset in the PSP could emulate the complete CPU of the PS1 to me (166 Mhz).

For the audio features of the ps1, except if you want to play mp3 instead of the cd track (well no cd drive on PSP right ? It should be pretty easy and not that costly to emulate.

Now for the graphic chipset of the ps1 -> VRAM structure may be causing some issue as the PSP and PS1 may have different format (=lot of work by cpu of the PSP to do conversion).

When it comes to rendering, the PS1 graphics system call could be translated to PSP graphic system call... I feel it would be rather simple. From my understanding the PS1 just has a display list that you transfer to the graphic chip which does the rendering for you.
In this case the emulator would just need to parse the renderlist and convert it to calls to the PSP render list... I bet with 5% or less CPU on the PSP all these calls could be translated to the PSP graphic chipset instruction format.

Until now the ps1 emu has been slow because they dont use ONE IMPORTANT FEATURE WHICH IS : THE CPU OF THE PS1 IS COMPATIBLE WITH THE PSP CPU.
In this case, they "emulate" completly the chip, which is very costly...
(33Mhz CPU cant be emulated on a 333Mhz cpu unlikely)
I heard also that the RENDERING was done in software, which is really a shame actually because translating the calls to PSP system call shouldnt be THAT difficult.

Of course, the reason for that is time and energy : using already existing C source of emu is easy, porting time is not that much... Writing a JIT and validate such technology would require many month man of work I believe.

Update : I read the site of PSPSOne, it seems that he implemented such technique but it didnt work as excepted (I tought register would be an issue but...)

I really believe that he should switch to hardware graphic acceleration. His first attempt gave him a 7x increase in cpu emulation performance. Even he can do may be x15 with a full JIT. I would have switched to the graphic emulation... Software is just TOO slow spending your time with for-loop to draw pixel.

[rosac]

waooo what a nice day for PSP ! I cant wait for this , good work dev's !! Thanks a lot

[lilvietquoc]

This is great news
GOOD WORK!
cant wait for the release
and maybe a posibility at playing FF7

[Acrodin]

Same here .... FF7 ... here we come! And with the 4gb HD, let the psx games roll in!
Also, cant wait to play Castlevania Symphony of the Night either! :)

[tryqus]

~Huggzorz to the Maxxzorz~

Yeah that about covers it.

[Joe88]

Go to psp updates. They have a beat release demo.

[Valiant]

err well it is more like a demo to check the speed...it doesnt play games. And I MUST SAY..the speed is very impressive (it exceeded my expectations). I love the crispness though...so beautiful. However, it is not really fast enough to play too much games, but I trust Pacman's effort for this is ery impressive.

[Voltron]

This is great indeed. Hopefully this will at some point play at full or nearly full speed with sound. With 4GB and 8GB PRO Duo cards to show up this year, complimented by the great homebrew scene, I look forward to enjoying the amazing PSP more and more.

[lilvietquoc]

Same here .... FF7 ... here we come! And with the 4gb HD, let the psx games roll in!
Also, cant wait to play Castlevania Symphony of the Night either! :)

AGH! Casltevania SOTN was one of the best 2D games i've ever played! =)
yet....i cheated alot in that...

but great job man
i really hope this turns out great

(metal slug..YAY)

[phucdup]

PSPSONE query. I noticed that the GP2X already has a PSX emulator working incase i am mistaken.
Can that be ported onto the psp rather than creating a new emul8r.
Also, windows 95 (and mac) can be emulated on a psp with bochs...can windows 95 run a pc PSX emulator, therfore, you could run a PSX emulator through the windws95 bochs port. Sorry if this sounds daft, i'm only 16 :eek: [B]