Masta-G: Keep dreaming...
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Masta-G: Keep dreaming...
Cast128 - 'Without sound' means there isn't as much to emulate for the Dreamcast. Afaik no one has yet found out how to communitate with the Dreamcast's ARM sound chip so all sound needs to be produced via the SH4 Main CPU and thus eats up a good bit of its power. Same goes for video btw: the only emus that make use of the Dreamcasts video power are GenesisPlusDC PVR Preview v3 & Bleem!cast (and some of Bero's FPS ports plus QuakeDC but that's been created with the WinCE dev kit) - everything else is generated by the SH4 and then send to the PVR.
The hardest things about SegaCD emulation to implement into GPDC would be the additional VDPs and custom FX video chips it has.
As far as my limited knowledge goes that's the reason why e.g. DreamSNES isn't fullspeed yet though the 2,5 MHz SNES CPU is emulated in SH4 assembly: The DC's SH4 has to generate SNES' sound + video - both are exactly what made the SNES as powerful as NeoGeo and MegaDrive/Genesis back in those days despite its incredibly weak 8bit CPU.
Masta-G, a Dreamcast won't ever emulate a P166 because SH assembly differs a lot from x86 and thus coding an emu like that would be a task that no one would like to attempt I guess.
You might as well get that illegal WinCE dev kit and port some Win games yourself before writing an emu for a whole bunch of games... Then again you could as well go with KOS and you even would be on the legal side.
fame is about 3-4x larger than c68k and at MOST 20% faster. It by no means blows it out of the water, and i'm sure that if someone were to, lets say re-write portions of c68k (the instructions themselves) in assembly it would probably get about the same speedup and maintain its size.Quote:
Originally Posted by SiZiOUS
I already ported a 386 emulator, not too far off =PQuote:
Masta-G, a Dreamcast won't ever emulate a P166 because SH assembly differs a lot from x86 and thus coding an emu like that would be a task that no one would like to attempt I guess.
I don't think that FAME is anywhere near finished. It works perfectly but it's not finished. If your suggestion would be something Fox68K could implement into FAME, I am sure he would do it. The Amiga emu that's been worked on should bring some optimizations and improvements for FAME with it.
Also what you write about FAME that "by no means blows it out of the water" is almost 100% caused by the Z80 cores that currently are beeing used. The Z80 is a hell of a CPU and its possibilities in C had been pretty much optimised with CZ80 I guess, but as there's no finished SH4 Z80 core. Let's give Fox68K the time he needs and have a look at things again. ;)
Fox has said that he no longer plans to work on fame and is going to go into making other cores instead.Quote:
Originally Posted by Christuserloeser
and that has nothing to do with z80 cores. fame vs c68k head on head gives about a 20% difference in speed. it has nothing to do with anything else, it's simply that fame is not significantly better than c68k. To me it gives an unacceptable tradeoff, almost a megabyte of space, for a minimal overall speed gain.
I see what you mean if you are aiming to gain as much RAM as possible for NeoDC's features.
Thing is I would never dare to say something like "Fame is not significantly better than C68K" because the DC specific SH4 68K core is "only" twenty percent faster than that as much as possible optimized C68K emulator =P
Though maybe you're correct. I'm sure Fox68K will eventually work on it again and would try to cut down its size plus gets a few percent here and there if he compares FAME with C68K...
20% in the m68k traslates to at most around 3% speed in the emulator. c68k isnt as optimized as possible too. Stef talked about a few more things he wanted to implement in it, if he did though I'm sure that it would get very very much closer to fame. Also, when I say twenty percent, that is the number that fox gives for his benchmarks, which are not only not real life, butwhen I compare the two I get c68k showing much better performance than stated.
This has all been discussed many times though, in the m68k thread and in other threads dealing with genesis or neo geo. People take neo4all and say, well it uses fame, so thats what makes it faster, when in fact it is almsot entirely the fact that fox re-wrote the renderer in asm (it isnt pvr hardware rendering like genesisplus, its just written in assembly). I would say that contributes almost entirely to the speed in neo4all over neodc, nothing to do with fame (oh, and the frameskipping and underclocking dont hurt either)
What Systems do i want emulated on DC? whatever the hell we get, cause these people put a lot into it. i wanted to say that the programmers, coders, porters, and all are really the people who choose what i play with, cause im such a fan of you all,and what you people do, i play with everything i get hold of. have a good one, cheers to site peoples, coders, play testers, and whatever it is that drives you all, thanks to you guys me n the wife can play our fave stuff again.
Wow!!!
You guys know a lot....How can i answer now...You *got* me i could say....
People love Dreamcast emulators.People all over the world comes to sites like that.
Lets consider that how many of them have the emulators burned!!!!
For example me.....I live some kilometers out of Athens(yea right iam Greek!!)
I visit this site everyday,a part of me, a part of my Dreamcast..........
Continoue your great work......A lot of nights my Dreamcast beged me to power it off because of you guys!!!!
Just for information, C68K's another core portable to DC ?Quote:
Though maybe you're correct. I'm sure Fox68K will eventually work on it again and would try to cut down its size plus gets a few percent here and there if he compares FAME with C68K...