Hacking Sega Genesis/CD emulator for DSTWO?

[uberpubert69]

Does anybody know of any efforts to improve Sega Genesis emulation on the DS? Or if there would be any substantial improvement in Genesis emulation using the DSTWO? Theres been lots of love for nintendo emulators lately, and was just wondering if anybody was planning on using the DSTWO SDK to make a better Genesis emulator than JenesisDS. Would love to play some Genesis/CD on my DSTWO.

 

[TheTitan]

That would be great indeed... don't know if DS could emulate Sega CD properly though...

 

[Rydian]

There's nothing specific for the DSTwo, and I've seen no plans.

Yes there could be improvement (including things like the ability to load those couple of largest-size ROMs), but the DS is ARM while the DSTwo is MIPS, so many programs cannot be ported easily without re-writing.

 

[uberpubert69]

There's nothing specific for the DSTwo, and I've seen no plans.

Yes there could be improvement (including things like the ability to load those couple of largest-size ROMs), but the DS is ARM while the DSTwo is MIPS, so many programs cannot be ported easily without re-writing.

I was hoping for a better version of picodrive like the one on the PSP. I understand theres difficulties with porting stuff, just wanted to throw the question out there to spark up conversation about the topic.

 

[2ndApex]

The DS has more than enough firepower to emulate the Sega Genesis, not sure why it would have to be DSTWO specific unless you wanted to port a PSP emulator or something.

 

[Rydian]

The DS has more than enough firepower to emulate the Sega Genesis, not sure why it would have to be DSTWO specific unless you wanted to port a PSP emulator or something.

The current emulator isn't full-FPS, and can't load some games like Sonic 3 + Knuckles.

 

[uberpubert69]

The DS has more than enough firepower to emulate the Sega Genesis, not sure why it would have to be DSTWO specific unless you wanted to port a PSP emulator or something.

I'm not sure if Sega CD emulation would be possible with the DS alone.

 

[granville]

The current emulator isn't full-FPS, and can't load some games like Sonic 3 + Knuckles.

I think it's probably fair to say that further improvements likely would have been made to JenesisDS had the author stuck with it. The author Lordus (AKA Stephen Dittrich) disappeared off the net years ago. Turned out he had been hired by Sega themselves to create their official Sonic collection on the DS, Sonic Classics Collection. It looks like it actually uses a modified version of JenesisDS with some tweaks and fixes here and there. Either way his name is in the credits but he never appeared online since then.

The speed I don't know about, though I could possibly imagine it being improved. A lot of the games actually run quite well already, fullspeed or close to it (there are exceptions here and there as well as slowdowns in some games). But besides just not ever getting around to it before being recruited by Sega, implementing support for games over 3MB in size likely wouldn't have been impossible to do. It has been done in other emulators that I didn't really notice any significant speed or compatibility reductions.

The rest of my post is directed more towards the topic creator and others as i'm sure Rydian knows these things already-

The reason Genesis emulation on DS is so fast is because it's a hardware based emulator as opposed to software. There was actually an earlier version of JenesisDS that came in a software variety (well before sound was implemented), its compatibility was apparently better and it didn't suffer from as many graphical glitches (it also supported scaling the sides of the image and not just the top and bottom). Because it was software-based, it ran quite slow, much slower than later versions of JenesisDS that eventually supported sound. It required a frameskip of at least 2 or 3 to get running at full speed. There was a port of Picodrive to the DS that was a similar situation regarding the speed. JenesisDS is a very good emulator considering the DS' limitations and i'd definitely say it's a very nice effort on Lordus' part, but there are reasons it happens to run so well and there exist issues that likely can't be corrected so easily (or perhaps at all) due to the methods by which it was programmed.

It's similar to the situation behind SnemulDS. That emulator is fairly fast and has sound, but the compatibility is even worse than JenesisDS and so are the graphical glitches. The DSTWO emulators are considerably slower despite the much faster processor, because they are far more compatible emulators. I believe they're ports of the very compatible and much more accurate SNES9x emulator.

I'd wager a Genesis emulator is perfectly possible on the DSTWO, especially since PSP has some. Though again it would likely follow the trend of the other DSTWO emulators for SNES and GBA. While it would probably be considerably more accurate and glitch-free with better compatibility, it is also likely to be much slower than JenesisDS and require a frameskip to run full speed.

 

[uberpubert69]

I think it's probably fair to say that further improvements likely would have been made to JenesisDS had the author stuck with it. The author Lordus (AKA Stephen Dittrich) disappeared off the net years ago. Turned out he had been hired by Sega themselves to create their official Sonic collection on the DS, Sonic Classics Collection. It looks like it actually uses a modified version of JenesisDS with some tweaks and fixes here and there. Either way his name is in the credits but he never appeared online since then.

The speed I don't know about, though I could possibly imagine it being improved. A lot of the games actually run quite well already, fullspeed or close to it (there are exceptions here and there as well as slowdowns in some games). But besides just not ever getting around to it before being recruited by Sega, implementing support for games over 3MB in size likely wouldn't have been impossible to do. It has been done in other emulators that I didn't really notice any significant speed or compatibility reductions.

The rest of my post is directed more towards the topic creator and others as i'm sure Rydian knows these things already-

The reason Genesis emulation on DS is so fast is because it's a hardware based emulator as opposed to software. There was actually an earlier version of JenesisDS that came in a software variety (well before sound was implemented), its compatibility was apparently better and it didn't suffer from as many graphical glitches (it also supported scaling the sides of the image and not just the top and bottom). Because it was software-based, it ran quite slow, much slower than later versions of JenesisDS that eventually supported sound. It required a frameskip of at least 2 or 3 to get running at full speed. There was a port of Picodrive to the DS that was a similar situation regarding the speed. JenesisDS is a very good emulator considering the DS' limitations and i'd definitely say it's a very nice effort on Lordus' part, but there are reasons it happens to run so well and there exist issues that likely can't be corrected so easily (or perhaps at all) due to the methods by which it was programmed.

It's similar to the situation behind SnemulDS. That emulator is fairly fast and has sound, but the compatibility is even worse than JenesisDS and so are the graphical glitches. The DSTWO emulators are considerably slower despite the much faster processor, because they are far more compatible emulators. I believe they're ports of the very compatible and much more accurate SNES9x emulator.

I'd wager a Genesis emulator is perfectly possible on the DSTWO, especially since PSP has some. Though again it would likely follow the trend of the other DSTWO emulators for SNES and GBA. While it would probably be considerably more accurate and glitch-free with better compatibility, it is also likely to be much slower than JenesisDS and require a frameskip to run full speed.

I wasn't bashing the developer for jenesisds or the emulator itself. I was just wondering how much better Genesis emulation could be with the DSTWO like if Sega CD emulation would be possible.

 

[granville]

I wasn't bashing the developer for jenesisds or the emulator itself. I was just wondering how much better Genesis emulation could be with the DSTWO like if Sega CD emulation would be possible.

I know you weren't. My post was simply an overall explanation on why Genesis emulation on DS is the way it is (for better and for worse). And also explaining the differences as well as some of the pros and cons you'd be dealing with in creating a "better" one for DSTWO. A DSTWO specific Genesis emulator (such as a port of PSP's Picodrive for example) would almost certainly sport drastically better compatibility and fewer glitches overall i'm sure. Though probably with the tradeoff of being substantially slower and requiring some frameskipping.

I really don't know about Sega CD support though. Has that happened on the PSP in any playable form? I gather the Sega CD had some hardware enhancements over the normal Genesis apart from just the addition of CD media. Like another dedicated and faster clocked CPU, and likely other similar hardware upgrades that compounded the Genesis' power (I also know it was capable of Mode7-like rotation and scaling of graphics that the Genesis wasn't capable of doing on its own).

 

[uberpubert69]

I know you weren't. My post was simply an overall explanation on why Genesis emulation on DS is the way it is (for better and for worse). And also explaining the differences as well as some of the pros and cons you'd be dealing with in creating a "better" one for DSTWO. A DSTWO specific Genesis emulator (such as a port of PSP's Picodrive for example) would almost certainly sport drastically better compatibility and fewer glitches overall i'm sure. Though probably with the tradeoff of being substantially slower and requiring some frameskipping.

I really don't know about Sega CD support though. Has that happened on the PSP in any playable form? I gather the Sega CD had some hardware enhancements over the normal Genesis apart from just the addition of CD media. Like another dedicated and faster clocked CPU, and likely other similar hardware upgrades that compounded the Genesis' power (I also know it was capable of Mode7-like rotation and scaling of graphics that the Genesis wasn't capable of doing on its own).

If I recall correctly (its been years since I used my PSP because its analog stick is F*$?!ed) Picodrive on the PSP was able to play Sega CD games just fine, but I do remember it taking forever for it to load the ISO files.

 

[VatoLoco]

gawd I wish the source for DSTwo Linux was available, so we could get some proper scaling for 256x192.
So, yeah, just sayin' there is a Picodrive for Dingoo that runs on the DStwo's Dingux port, but scaling looks like garbage, or you lose the video edges by zooming to 320x240.
Just tried out Sonic & Knuckles. Booted and plays fine enough.

edit: played a couple of cd games, and Earthworm Jim and Robo Aleste both run, albeit a bit choppy- tho i didnt mess with any setting to optimize.

 

[Rydian]

Just tried out Sonic & Knuckles. Booted and plays fine enough.

It was Sonic 3 & Knuckles that was too large.

 

[VatoLoco]

certainly sir, but irregardless, its PicoDrive on the DS(two).
To be specific (i didnt know there was any variations of the game) Sonic3 & Knuckles boots and runs
fine=P

 

[KoopaHax35000vr]

CD would most likely lag a lot.

 

[granville]

I didn't even think about using the Linux port on DSTWO to gain access to another Genesis emulator. I haven't tried Linux on it myself and now i'm curious as to how well it runs Picodrive. Interesting to note that Sega CD games work as well.

@VatoLoco
When you say games are choppy, can it be compared to the choppiness in the SNES and GBA emulators on DSTWO? Or is it better or worse? And is it just CD games that are choppy, or are regular non-CD Genesis games choppy as well?

 

[2ndApex]

gawd I wish the source for DSTwo Linux was available, so we could get some proper scaling for 256x192.
So, yeah, just sayin' there is a Picodrive for Dingoo that runs on the DStwo's Dingux port, but scaling looks like garbage, or you lose the video edges by zooming to 320x240.
Just tried out Sonic & Knuckles. Booted and plays fine enough.

edit: played a couple of cd games, and Earthworm Jim and Robo Aleste both run, albeit a bit choppy- tho i didnt mess with any setting to optimize.

Gah don't remind me. Cave Story, The Zelda ROTH fan game series, and select PSX games all run great but the way it's scaled makes them all look so darn ugly and unappealing.

 

[VatoLoco]

@ 2ndApex, true enough about scaling, but zoom(L+start) isnt so bad, i just liken it to the scaling in dsx86/ds2x86, the stuff wasnt really meant for 192x256, but it pretty darn close.
@granville, just the cd games were choppy, earthworm jim was not even enjoyable. But, like i said, i havent messed with any of the emu settings (frameskip/audio/etc). i'll dick around with some settings this evening and see if i cant get Jim to groove smoover.

 

[Another World]

I really don't know about Sega CD support though. Has that happened on the PSP in any playable form?

i believe that the sega cd emulation found on the psp is a port of the engine from GENs. it runs rather well. i've tossed a few isos at it and haven't had any issues. at one point alekmaul was working on a port of heart of the alien for the ds. he had told me that it was running and he only needed to work on the sound. i've no idea if it ran at full speed or what glitches i could have debugged, he never released it and eventually moved on to his SNES library and the GCW Zero.

About homebrew scene : Hota works with sound, update of Flashbask and Anotherworld are also OK. I just need time to prepare them for release.

-another world

 

[gusmento01]

If you don't have a PSP and have some extra money laying around, I would suggest you to buy a PSP and use Picodrive, I doubt DSTWO will have Sega Genesis emulator as decent as Picodrive for PSP, you could also get a PSP Sega Genesis Collection for a very cheap price(I paid $4,99 at Amazon).