Best Genesis/Mega Drive emulator for DC?

[Christuserloeser]

This doesn't sound like you'd have played around with the settings (C68K/FAME)...

M.U.S.H.A. worked but it was a bad rom since it wouldn't go past the sega screen

That's not an indicator for a bad ROM. The good dump does that too, but at least you can play it in SW (which is slow). You should use GoodTools to check your ROMS: http://www.allgoodthings.us/

[XxFilthEOnexX]

no, actually M.U.S.H.A. did the same thing on the preview 3 version so I think it was a bad rom.

[alb3530]

I have a Symbian S60 phone, and there's a Genesis emulator for this platform, called "PicoDrive".Comparing it with GPdc, of course the latest build of Genesis Plus is much better, cause it runs most games at full speed with sound enabled.
PicoDrive runs most games at full speed, but with sound disabled.But a thing i've noticed is the performance of both emulators in racing games.Let's take Out Run and Super Hang On as an example:
While Genesis Plus runs the games slow and with frame skipping when sound is enabled and SW mode is used (must be used to avoid problems with the track), PicoDrive runs almost at full speed.As in Genesis Plus, the sound is slow in both games.Picodrive plays all sound channels, sound is mono and sample rate is 16khz.

Now, if sound is disabled in both emulators, Genesis Plus will run prattically the same way, but PicoDrive runs at full speed, with no frame skipping.You can watch some videos recorded by cristfc while the emulator was running these games on my Nokia 6681.The videos quality isn't so good due to light factors, but it's possible to realize the games running at full speed.

http://www.yourfreespace.net/users/alb3 ... hangon.3gp

http://www.yourfreespace.net/users/alb3 ... outrun.3gp

http://www.yourfreespace.net/users/alb3 ... outrun.mp4

http://www.yourfreespace.net/users/alb3 ... _sf2ce.3gp


Of course, the phone doesn't deal with nothing like 320x224 pixels.It has a 176x208 screen, and considering i'm playing in landscape mode, we could say it's 208x176.In this mode, Genesis screen fits to the phone's screen, then some pixels aren't displayed.There's a interpolation option, that doesn't affect the performance.Plus, the phone has many tasks to deal with simultaneously, like Bluetooth server, Fax modem server, Calendar server, loggers, Watchers, Plugins, etc, etc.

I think the code of PicoDrive can't help Dreamcast developers cause in PicoDrive lots of C code were moved into optimized ASM.But what about the performance when running racing games?Is it fast due to the small screen only?Or is it phone's CPU architecture that makes it easier to have a Genesis emulator running racing games so well?

[Christuserloeser]

I think the difference in emulating 3d bitmap racing games like Out Run, etc. is because of the hardware renderer in Genesis Plus DC. The video renderer has been rewritten by BlackAura for the Dreamcast's PowerVRII (which required a lot of work and something that's very special in this emulator as about all other Dreamcast emulators like e.g. DreamSNES use the Dreamcast's main CPU for video emulation and only send the video output to the PowerVRII). I think that these games are using a feature of the Genesis' VDP that BlackAura's HW does not yet feature.


If the Symbian S60 (or any other device that has a Genesis/MegaDrive or SMS/GG emulator) would feature a Super Hitachi CPU then I assume that there actually could be some useful code for GenesisPlusDC.


Hm, that remembers me of something: A while back I found a 68k emu in ARM assembly: http://www.finalburn.com/mobile/index.html (The source code is also available)

Cyclone 68000 is an assembler 68000 emulator for low-powered ARM-based machines such as the Pocket PC and a number of mobile phones.

Now I wonder if the Dreamcast's ARM7 could be used for anything ?

I know it only has 24Mhz/32bit but what if there would be a Z80 emu in ARM assembly ? or what if CZ80 would be compiled for running on the ARM7 ? I remember reading that the Z80 could be underclocked to the lowest possible speed and still would work:

I wonder if FAZE (once it's finished) could provide at least a little speed boost...

Maybe, but it won't be very much.

If you remember back when the original GP/DC was released, it had an option to adjust the Z80 clock. Changing the clock to the lowest possible speed sped things up significantly. That option is no longer there, because it makes no noticeable difference anymore.

So maybe when CZ80 would be compiled for the ARM7, and then underclocked - would that... work ?


Hm, I also noticed that I haven't answered your entire reply at all:

It's the sound emulation that's slowing things down, right ?

Yep. Turn that off, and it's 100% full speed. Even the software rendering is fast enough in that case. Most games just aren't as enjoyable in total silence.

I haven't asked this yet, but would it be possible to enable some little auto-frameskip for the SW renderer too ? Atm SW seems to run without any frameskip and sound emulation isn't keeping up with it.

I mean it really would only make sense for the few games that are still broken in HW, but I thought to ask for it anyway ^^


(Hm, maybe if the auto-frameskip would aim at 50Hz it would be not be noticably at all ?)

I remember you have been working on the sound code back in 2004, do you think it would be worth trying again to get it working?

Actually, this version's sound code is very similar to PVR5's. The main differences are that it's slightly simpler, uses frameskipping to keep the audio and video in sync, and that it works properly.

There's a whole heap of optimisations that could be done on the sound code without radically altering it.

Ah, great to hear that: It's really good news!

[lbm5007]

Has anyone tried Stealth's Hack of Sonic the Hedgehog 1 with Sonic and Knuckles with the new Genplus. If you have did it work because when I tried it it froze for me.

[alb3530]

Has anyone tried Stealth's Hack of Sonic the Hedgehog 1 with Sonic and Knuckles with the new Genplus. If you have did it work because when I tried it it froze for me.

What about a checksum fix feature?Some sonic hacks don't work with the emu

checksum fix will be good feature...
it remember kgen fo windows which have checksum fix

[lbm5007]

Does this mean that the game will someday be playable if that checksum thing is added. I just think it would be cool to play with knuckles on sonic 1 on the DC

[Christuserloeser]

Sonic 1 + Sonic & Knuckles isn't Sonic 1 with Knuckles. You will get a good set of Sonic 3 bonus stages though.

[jessman]

But there's a hack out there {I have it} where you can play through Sonic 1 WITH Knuckles. You can even glide and spin-dash.

[Christuserloeser]

So maybe when CZ80 would be compiled for the ARM7, and then underclocked - would that... work ?

At Jeff Frohwein's GBA dev site, I found some ARM compilers:
http://www.devrs.com/gba/software.php


Even two ARM Z80 emulators:

2002/06/30 - Peter's Z80 Emulator - Posted by: Jeff Frohwein
This z80 core emulator was written to run on a StrongARM processor but it might can be adapted to the GBA's ARM7 processor. Here are some other CPU cores for ARM processors:
Foon - z80 core

[cristfc]

But there's a hack out there {I have it} where you can play through Sonic 1 WITH Knuckles. You can even glide and spin-dash.

like tails in sonic 1?
tails fly and executes spindash...

take a look in http://www.sws2b.com

this hack (tails in sonic 1) dont work in genesis plus, possible because checksum...

[BlackAura]

A lot of those ROM hacks don't work in the PC version either. Many of them have the checksum routines disabled. I have no idea what's wrong with them.

[alb3530]

I was thinking about that, cause i've noticed the hacks normally work even on those emulators that perform the checksum.
I mentioned the checksum thing just cause in my phone, Tails in Sonic 1 hack works without problems.
BlackAura, would this latest build of Genesis Plus refuse to run a ROM that has checksum routines enabled if one byte is changed in it?


I've noticed a bug that happens sometimes.You try to load a ROM, and after the ROM is loaded, what you get is a static image of a game that was already loaded.See this example: http://www.yourfreespace.net/users/alb3 ... lusBug.3gp
(121,27kb)
here i had already played Revenge of Shinobi.Then i tried to load another ROM (Sonic 3) and what came next is a frozen image of Revenge of Shinobi.It was happening only in SW mode with sound disabled.

By the way, would it be possible to allow switching between video modes (HW and SW) in the middle of the emulation, thus making it possible to overcome some problems, like the white menu that happens with FIFA '95 in HW mode?Or is it completely impossible to implement?

[lbm5007]

O well thats too bad thanx for the help though

[cristfc]

I was thinking about that, cause i've noticed the hacks normally work even on those emulators that perform the checksum.
I mentioned the checksum thing just cause in my phone, Tails in Sonic 1 hack works without problems.
BlackAura, would this latest build of Genesis Plus refuse to run a ROM that has checksum routines enabled if one byte is changed in it?


I've noticed a bug that happens sometimes.You try to load a ROM, and after the ROM is loaded, what you get is a static image of a game that was already loaded.See this example: http://www.yourfreespace.net/users/alb3 ... lusBug.3gp
(121,27kb)
here i had already played Revenge of Shinobi.Then i tried to load another ROM (Sonic 3) and what came next is a frozen image of Revenge of Shinobi.It was happening only in SW mode with sound disabled.

By the way, would it be possible to allow switching between video modes (HW and SW) in the middle of the emulation, thus making it possible to overcome some problems, like the white menu that happens with FIFA '95 in HW mode?Or is it completely impossible to implement?

what about the 6button map for play street figher?? could be different i think..

[Juan]

I've noticed a bug that happens sometimes.You try to load a ROM, and after the ROM is loaded, what you get is a static image of a game that was already loaded.See this example: http://www.yourfreespace.net/users/alb3 ... lusBug.3gp
(121,27kb)
here i had already played Revenge of Shinobi.Then i tried to load another ROM (Sonic 3) and what came next is a frozen image of Revenge of Shinobi.It was happening only in SW mode with sound disabled.

C68K breaks when sound is disabled.

[SACEONE]

i have been trying to burn the gens plus emu for dc to no avail i have followed the instrutions on here to the letter. it wont load up it keeps going to the cd player i have already wasted a whole pack of 25 cd's just went and bought a new pack i refuse to even try plz sum one tell me what i am doing wrong i am doing that sbi thing etc i read hot to very carefully did what it says and nothing.

[SACEONE]

ok all i finally got it to work but now when i press start to play a game nothing happens can som one help me with this plz really want to see this emu play lol.

[lbm5007]

ok all i finally got it to work but now when i press start to play a game nothing happens can som one help me with this plz really want to see this emu play lol.

I had the same problem. The problem with mine was that my roms had different names than what the romlist program had listed. It took all the spaces and other symbols and listed them as underscores, so I just copied all the filenames from the roms.txt to the actual file names of the roms. I know that seems like a lot of work, but it will be worth it in the end and maybe someone else knows a better way. I am pretty new with this stuff.

[Juan]

Monster World IV (at least the english translation) hangs when entering the ice pyramid