What About Saturn Emulation?

[Yrx]

I was under the impression that Saturn rendered in squares (as opposed to triangles), which is why the graphics looked blocky. You need a heck of a lot more squares to round out a shape.

But yeah, this entire graphics argument is kind of dumb. All I know is I want my Saturn exclusives. h34r:

 

[MarkoeZ]

That's pretty impressive. Why was it canceled?

as far as i can tell from the comments on youtube it was released for the ps2. but correct me if im wrong.

edit: hmm refresh after watching a vid, posts go fast here

 

[bustaballs]

I meant why was the Playstation project canceled. Shenmue was also released, just on the Dreamcast.

 

[x68000]

The likes of Labotomy's Saturn port of Exhumed was much more accomplished with a better engine than the PSX version. Just try both versions and see for yourself! Tomb Raider was superior on saturn too.

Obviously 2D titles were better on the saturn, eg capcom and snk fighters, konami shooters and technosoft/treasure games such as TF V & silhouette mirage.

Although the PSX did have a few great exclusive 2D titles such as Gradius Gaiden, Zanac x Zanac and the toaplan shooter collections.

 

[anexanhume]

I meant why was the Playstation project canceled. Shenmue was also released, just on the Dreamcast.

It wasn't. ICO was released on the PS2 to much acclaim.

 

[Rivroner]

The likes of Labotomy's Saturn port of Exhumed was much more accomplished with a better engine than the PSX version. Just try both versions and see for yourself! Tomb Raider was superior on saturn too.

Obviously 2D titles were better on the saturn, eg capcom and snk fighters, konami shooters and technosoft/treasure games such as TF V & silhouette mirage.

Although the PSX did have a few great exclusive 2D titles such as Gradius Gaiden, Zanac x Zanac and the toaplan shooter collections.

Totally agree with you.

I had fun with my PS not a Saturn but those titles had a better Saturn version.

 

[Pleng]

I meant why was the Playstation project canceled. Shenmue was also released, just on the Dreamcast.

It wasn't. ICO was released on the PS2 to much acclaim.


Im pretty sure that bustaballs was referring to the PS1 project being canceled.

ICO moves from PSX to PS2
Shenmue moves from Saturn to Dremcast

 

[Turnip]

Saturn is a console I never played on much so id love it to be emulated on pandora since all the great games exept the popular arcade ones like daytona will be new to me. From what I gather the mega cd was a pretty complicated piece of hardware and someone got the gp2x emulating that pretty well, perhaps this project needs the same guy.

 

[Firefox]

I've studied hardware for both in great depth and Saturn wins in every way. The 2x RISC on Saturn are superior to the 2x RISC on Jaguar (not just clock speed, Jaguar's RISC CPUs have serious bottlenecks), the 2D acceleration is superior, the 3D acceleration is superior, the Saturn has 2 DSPs in addition, real audio acceleration instead of just having a couple DACs - do you see where I'm going with this? If you want to substantiate what you said do so with a sound technical argument. I said Saturn was significantly more powerful, not "will squash Jaguar like a bug." But Jaguar has zero advantages IMO.

Hmmm... That's quite an interesting comparison to consider.

Both systems have a 68000 clocked at a similar speed. The Jag has two custom RISC processors, the Saturn has two SH2s, both also running at a similar clock speed. Both are two-address instruction set RISC processors.

I think the Jag's RISC processors are a bit more powerful, certainly for games programming. They have to run code from their 4kB and 8kB blocks of SRAM to get decent performance of course (usually reloaded by the blitter), whereas the Saturn's SH2s have a proper cache system with 4kB of cache in each - but have to run code in that cache to get decent performance. The SH2s will slow down a lot when they "run on" to the next little 4kB block of code. So I think both consoles are well matched in that department.

I think the Saturn's big advantage is its VDP1 graphics processors, which look a lot more powerful than the Jag's OP + blitter combo. And, as Exophase noted, the Saturn has two DSPs as well - one to do 3D geometry processing and one to do sound. That's a lot of extra power, but tons of extra complexity for both game and emulator developers.

 

[Rivroner]

Firefox, what do you think about possible Saturn emulation? It is possible at decent gameplay speeds? Thank you

 

[Exophase]

Both systems have a 68000 clocked at a similar speed. The Jag has two custom RISC processors, the Saturn has two SH2s, both also running at a similar clock speed. Both are two-address instruction set RISC processors.

The 68k on Jaguar steals massive main bus cycles if you have it do anything but halt out entirely. It's dead weight.

I think the Jag's RISC processors are a bit more powerful, certainly for games programming. They have to run code from their 4kB and 8kB blocks of SRAM to get decent performance of course (usually reloaded by the blitter), whereas the Saturn's SH2s have a proper cache system with 4kB of cache in each - but have to run code in that cache to get decent performance. The SH2s will slow down a lot when they "run on" to the next little 4kB block of code. So I think both consoles are well matched in that department.

I disagree - I think the SH2s on Jaguar are a lot better because they don't have the kind of register/pipeline stalls that the JRISCs do. Even Atari claims that you'll only get 75% efficiency from well optimized code. As far as cache is concerned, it doesn't work in the way you described. It'll be constantly reloading for every cache line, not 4KB at once. Cache tends to do much better than scratchpad because it's transparent, so you don't have to waste cycles and code space on routines to load what you want, and because it's more burst friendly (since it loads entire cache-lines sequentially). It's also possible to employ decent replacement strategies and mark what is and isn't dirty for retirement, something that can't really be managed with scratchpad. Of course, you can also configure half of the cache to act as scratchpad on Saturn as well.

The Jaguar's second JRISC (DSP with 8KB of scratchpad) is brought up a lot as a good source of power, but the way I see it, if you want audio that greatly surpasses NES level then you're going to have to spend a good amount of space on mixer code and possibly samples (although loading them from main memory probably won't hurt that much). Scratchpad is not good for general purpose code since it can't quickly move from one region to another - by not putting dedicated audio hardware aside from DSPs in the Jaguar Atari was fully intending for you to use the DSP for audio and nothing more. If you use it for general purpose computation then you're probably going to short change the audio quality, especially if you want to try to match Saturn level. Saturn doesn't have this problem since it has a lot of dedicated hardware for audio.

I think the Saturn's big advantage is its VDP1 graphics processors, which look a lot more powerful than the Jag's OP + blitter combo. And, as Exophase noted, the Saturn has two DSPs as well - one to do 3D geometry processing and one to do sound. That's a lot of extra power, but tons of extra complexity for both game and emulator developers.

Also VDP2, but yeah, with what you said ^_^

Incidentally, I also think that the DSP used for geometry calculation in Saturn is a lot weaker than the GTE in PS1, meaning that PS1 should have a lot more geometry potential (but raw triangle capacity might limit even things out for both).

 

[jbr]

Thanks for the analysis, Exophase, but I think this discussion is pointless.
Arguing that we shouldn't port a perfectly good open source saturn emu because the playstation was better is like saying "why bother with a SNES emulator? The gamecube was so much more powerful!"

I for one just want to play my saturn exclusive games. If you like other games better, (like ones for the playstation), don't use the saturn emulator. If you're a dev, the above still applies. If you like the satrun, port yabause. Of you don't, work on a project you do like.

I think it would be great if we had a playstaion, saturn, and jaguar emulator, becuase at least then everybody would be happy (although I do agree that the jag had virtually no good games).

 

[Exophase]

You shouldn't port a Saturn emulator with any decent expectations because it'll be too slow. If you think that a simple port of Yabause is going to have good results then you're kidding yourself. That argument should have been over a long time ago. No one has been arguing that anything shouldn't be emulated (except Zor Prime, but that was pretty summarily dismissed).

 

[jbr]

Ugh, I just realized how stupid I sounded.
I don't expect anything more than the Yabause port for the wii. Let's leave it at that.
Actaully, I'm not sure how much it matters, but the Yabause team has asked that people contribute to their trunk rather than make their own independent forks.
Like I said, I'm just hoping a developer that is in to the saturn will decide to work on improving Yabause, etc. for the pandora for the enjoyment of anyone who actually likes the saturn.

 

[polkunus]

Nights? radiant silvergun? poof! i think im going to cry

 

[CyruzDraxs]

I don't really expect anything either...but my offer still stands. I hope someday I'll be able to play my Saturn games without having to have access to a TV.

 

[Exophase]

I don't really expect anything either...but my offer still stands. I hope someday I'll be able to play my Saturn games without having to have access to a TV.

What's wrong with SSF? Or did you mean on something portable? Take it laptops don't count?

 

[Kyo]

I don't really expect anything either...but my offer still stands. I hope someday I'll be able to play my Saturn games without having to have access to a TV.

What's wrong with SSF? Or did you mean on something portable? Take it laptops don't count?

I don't know about him, but for me that's the case. I've never been much of a console gamer, The only thing I really play on is my homebrew enabled DS

 

[Firefox]

The 68k on Jaguar steals massive main bus cycles if you have it do anything but halt out entirely. It's dead weight.

Surely if the RISC processors are running from their scratchpad SRAM there will be main memory bandwidth to spare? (Although the RISC processors will obviously have to use some bandwidth to produce useful output.)

I disagree - I think the SH2s on Saturn are a lot better because they don't have the kind of register/pipeline stalls that the JRISCs do. Even Atari claims that you'll only get 75% efficiency from well optimized code.

Is this the register scoreboarding bug you're talking about, or something else?

As far as cache is concerned, it doesn't work in the way you described. It'll be constantly reloading for every cache line, not 4KB at once. Cache tends to do much better than scratchpad because it's transparent, so you don't have to waste cycles and code space on routines to load what you want, and because it's more burst friendly (since it loads entire cache-lines sequentially). It's also possible to employ decent replacement strategies and mark what is and isn't dirty for retirement, something that can't really be managed with scratchpad. Of course, you can also configure half of the cache to act as scratchpad on Saturn as well.

I know how cache works, but I'd imagined that Saturn games developers would aim for working sets that come to about 4kB to avoid cache misses as much as possible. I suppose they could have lots of fun analysing and optimising their code to interact with the cache in a more sophisticated manner, though strangely a lot of programmers facing deadlines somehow don't see that as "fun".

The Jaguar's second JRISC (DSP with 8KB of scratchpad) is brought up a lot as a good source of power, but the way I see it, if you want audio that greatly surpasses NES level then you're going to have to spend a good amount of space on mixer code and possibly samples (although loading them from main memory probably won't hurt that much). Scratchpad is not good for general purpose code since it can't quickly move from one region to another - by not putting dedicated audio hardware aside from DSPs in the Jaguar Atari was fully intending for you to use the DSP for audio and nothing more. If you use it for general purpose computation then you're probably going to short change the audio quality, especially if you want to try to match Saturn level. Saturn doesn't have this problem since it has a lot of dedicated hardware for audio.

That's a fair point.

I think the Saturn's big advantage is its VDP1 graphics processors, which look a lot more powerful than the Jag's OP + blitter combo. And, as Exophase noted, the Saturn has two DSPs as well - one to do 3D geometry processing and one to do sound. That's a lot of extra power, but tons of extra complexity for both game and emulator developers.

Also VDP2, but yeah, with what you said ^_^

Ah, I thought the Saturn had two identical chips called "VDP1". But now I read up on it a bit I see that they are quite different. It's been a while since we last discussed the Saturn.

Thanks for the analysis, Exophase, but I think this discussion is pointless.

Some of us enjoy these types of discussion just for the sheer technical interest.

 

[PokeParadox]

I also find the discussion interesting, even though I would be a little out of my depth trying to contribute to it.