Saturn Emulator?

Ian Micheal · Post by **Ian Micheal** » Sat Jun 19, 2004 12:02 am

You can change it via a flag to compile little or big On the real sh4 chip is my point. You can change it software and for the sh4 chip. Dreamcast you need to write a layer inbetween.

Post by **BlueCrab** » Sat Jun 19, 2004 12:24 am

The SH2 interpreter that I'm writing for the emulator in SuperH asm is about the closest we'll get to that.

BTW, A pin on the dreamcast's mainboard would have to be changed in order to get the sh4 to run in big-endian mode.

Ian Micheal · Post by **Ian Micheal** » Sat Jun 19, 2004 12:41 am

Sounds intresting. If you can take the load of i forget the name of this type of emulation. Were you take the same cpu or compatable to emulate on the same machine. It's got a name just cant remember it . Simulating it I guess would be the best anwser.

BlackAura · Post by **BlackAura** » Sat Jun 19, 2004 12:49 am

Virtualization? Like VMWare does?

The catch is that just wouldn't work, because of the endien thing. You'd end up having to write a binary translator anyway, and they tend to be pretty fast (much faster than interpreters anyway).

Ian Micheal · Post by **Ian Micheal** » Sat Jun 19, 2004 2:49 am

Yeah thats it

.

It would work if we changed it like blue crab said on the mboard there is a pin to change the endien ness . Who would do this and risk the damage.

Binary translator he is going to have to code. Serous work and time and effort this is going to take. I dont thing sh4 asm well help that much.

q_006 · Post by **q_006** » Sat Jun 19, 2004 3:14 am

honestly the best way it seems now is to:

1) write the functions header in C and the body in SH-4 asm
2) when that works.... convert the functions headers to asm also.

that way the entire program is in 100% asm.

but anyway i hope Bluecrab and MetaFox are able to get over these hurdles

Post by **Christuserloeser** » Sat Jun 19, 2004 3:25 am

I guess they will, since they'd not start the attempt if they don't think it would be possible

Greets and best wishes to all of you,

Chris

Post by **Christuserloeser** » Sun Jun 20, 2004 3:57 am

MetaFox wrote:For those who don't know, Saturation is a Saturn emulator I set out to make sometime around 1997 for PC, at which point I learned I was way over my head. Chuck Mason (of Gleam! fame) offered to help - and Semu was born from that.

Is Chuck Mason still active with this project too?

Chris

MetaFox · Post by **MetaFox** » Sun Jun 20, 2004 12:54 pm

BlueCrab wrote:
MetaFox wrote:
Warmachine wrote:yea Meta, just team up with with BlueCrab.
They're two different projects. I'm sure we'll share with each other like with the Genesis emulators, but I'm not going to stop my project just because his is coming out.
I'd be glad to accept any help, that you're willing to give. Also, I'd be willing to help out you too.

But, of course. Saturn emulation is going to be a tricky one to get working on Dreamcast, and open sharing is the only way to get it done.

BlueCrab wrote:By the way, Project L started as a saturn emulator from scratch for me too.... I got lost when working on something or another though.... I'm gonna try to incorporate some parts of the original project L code into this emulator though, mainly the Assembler CPU interpreter that I got about 70% done.

I didn't mean any offense, or to seem like I was implying my emulator was superior due to yours being ported - on the contrary. Yabause is an emulator in it's very preliminary stages, and it will take a lot of work to improve. Once you add more to it, it will become less like a port and more like a project of it's own once it becomes more advanced. Even LASER started out as an update to SinVader - but there is very little left to show that fact. I'm sure Yabause-DC will become the same some day.

Christuserloeser wrote:Is Chuck Mason still active with this project too?

Sadly, no. The last I've heard from Mr. Mason is when he offered to be a newsposter on Laseremu.com.

Post by **BlueCrab** » Sun Jun 20, 2004 7:40 pm

MetaFox wrote:I didn't mean any offense, or to seem like I was implying my emulator was superior due to yours being ported - on the contrary. Yabause is an emulator in it's very preliminary stages, and it will take a lot of work to improve. Once you add more to it, it will become less like a port and more like a project of it's own once it becomes more advanced. Even LASER started out as an update to SinVader - but there is very little left to show that fact. I'm sure Yabause-DC will become the same some day.

I didn't think you did, I was just stating it in a matter of fact type statement

bender · Post by **bender** » Mon Jun 21, 2004 12:29 pm

I don'?t know ... what about rewriting all asm ops with the bytes in the inverse order for the endianess matter and use only the new ones for your emulator? for example, to make an add_b and use it instead the normal add.

My asm level it's very limited, and i don't know anything about emulation. I think that even with the endianess problem, a sh4 it's more similar to a sh2 that a x86 cpu is. You can't compare both CPUs speaking about frequencies needed when emulating on a x86(this is even CISC

), both are very different and the sh4 should have an important advantage in the case of the sh2s

uncleben · Post by **uncleben** » Mon Jun 21, 2004 12:42 pm

Every modern CPU is RISC. Even x86 CPUs have an internal RISC core.
I think the Sh4 has a lot of advantage over the x86 to emulate a Sh2, so let's hope that it can be done

Alexvrb · Post by **Alexvrb** » Mon Jun 21, 2004 7:19 pm

uncleben wrote:Every modern CPU is RISC. Even x86 CPUs have an internal RISC core.

This is true, but on a hardware level. I wouldn't think x86 code is really all that different from what it used to be, just MORE, right? So from that point of view it is still CISC and very different from SHx.

Does anyone know if the Yamaha FH1 has anything in common with the Yamaha DSP in the DC, something that could be of use?

Orange_Ribbon · Post by **Orange_Ribbon** » Mon Jun 21, 2004 10:12 pm

You mean we might have Nights on DC. That is utterly amazing, and I wish you two the BEST of luck.

Ian Micheal · Post by **Ian Micheal** » Tue Jun 22, 2004 4:28 am

Hmm games running at all will be a task.

Post by **Christuserloeser** » Tue Jun 22, 2004 4:56 am

Yes, but it could be possible I guess

We just don't need to expect it in the near future. And it might be slow and low res the first time anyway but maybe the PowerVR2 allows to add hires without too much speed loss like it did that nice filtering on NeoCD or the VBA32 port or Bleem!cast too.
Would be to fantastic to be true I guess

Chris

Alexvrb · Post by **Alexvrb** » Tue Jun 22, 2004 1:09 pm

Resolution isn't the big issue here. The big issue is trying to emulate all the chips needed to run some games at something approaching playable. Mask and some others were throwing around ideas over at SX, as BlueCrab is probably aware.

Post by **Christuserloeser** » Tue Jun 22, 2004 1:12 pm

I know that the res isn't the prob - I was just dreaming

Chris

q_006 · Post by **q_006** » Tue Jun 22, 2004 1:30 pm

if anyone wanted to know the specs of the Saturn offhand here's a link.
http://darkwatcher.psxfanatics.com/cons ... aturn.html
http://www.sega-saturn.com/hardware.htm

abydos1000 · Post by **abydos1000** » Tue Jun 22, 2004 3:40 pm

That second link is a great one (miss Dragon Warrior). I guess the first site answers my long standing questions of why both processors could never really be used at the same time and parallel processing could only be used in a very limited capacity. Must have been an after thought and marketing ploy.

Thing is, wasn't there one or two games that made very limited use of both processors (maybe it was the sonic game that was never released)? That would be painful to emulate.