Genesis Games

[Squidge]

I've now figured out some details for my Genesis emulator, and how it will work, etc. It should allow for full speed emulation (no frameskip required) with full sound at 133mhz or possibly lower.

The problem is, the current design only allows 2mb (2,097,152 bytes) for the rom image, due to the 68k emulator taking up 4mb of ram, and the rest allocated to the video and z80 system.

Question is, would this be enough? Anyone know what kind of percentage of games are 2mb (bytes, not bits) and under?

I don't want to reduce the space allocated to the 68k emulator, as even reducing it to 2mb (to allow 4mb roms) would literally half the speed of the emulation.

 

[frolik]

I've been looking through a large list of roms in .smd format and the filesizes are all under 2Mb except two which are Sonic 3D Blast (2,606k) and Sonic Warrior (2,511k).

Many of these SMD files are only a few hundred kb. Hope this helps, I'm presuming that the file sizes reflect how much RAM they will consume.

edit: included filesizes

 

[frolik]

Just performed a search in a p2p prog on .smd files and it showed about 30 roms that were over 2mb, and about 60 roms that were listed as 2.00Mb - didn't give an exact filesize.

I'd say that they handful of games that you couldn't play on it would not matter too much, but I'm no megadrive games expert

 

[phoda]

Squidge,

Have a look on the roms database using Romcenter (www.romcenter.com) - you can dowload the datafiles also on the "Good" link, on the left side.
The most current "GoodGen" database mentions 4189 ROMS - several are bad dumps, overdumps etc. but a raw look over it says that 368 ROMS are over 2Mb - less than 9% of the database.

Later I'll try to filter out the "trash" roms - overdumps, pirates, etc. and see how this changes.

 

[TandeM]

I believe the largest ROM was Super Street Fighter II at 5MB (but the SNES version was better anyway), followed by the merged Sonic 3 + Sonic & Knuckles (and many others) at 4MB.

I believe Sonic 3 and Sonic & Knuckles are 3MB apiece; don't quote me on that.

 

[Drumaster]

I've now figured out some details for my Genesis emulator, and how it will work, etc. It should allow for full speed emulation (no frameskip required) with full sound at 133mhz or possibly lower.

The problem is, the current design only allows 2mb (2,097,152 bytes) for the rom image, due to the 68k emulator taking up 4mb of ram, and the rest allocated to the video and z80 system.

Question is, would this be enough? Anyone know what kind of percentage of games are 2mb (bytes, not bits) and under?

I don't want to reduce the space allocated to the 68k emulator, as even reducing it to 2mb (to allow 4mb roms) would literally half the speed of the emulation.

Full speed without frameskip, FULL sound and all that at 133 Mhz?!!!

If you perform that, you'll become my second god Squidge!

 

[phoda]

I fileterd out most of the duplicate roms - list went down to 1057 roms. Out of those, 82 roms are over 2Mb - a little under 8% of all roms.

The biggest one is Super Street Fighter 2, with 5Mb.

Since Darius 21, Raiden Trad and Sonic The Hedgehog are not over 2Mb I don't care

I believe it's definitely worth it leaving out 8% of the roms in exchange for twice the emulation speed. It's a no brainer.

 

[Samuel]

WHAT THE HELL ARE U SAYING? ARE U CRAZY? IT WILL SUPPORT ROMS TILL 4 mb i'VE JUST ASKED RLYEH! DON'T LIE AND GET INFORMED BEFORE SAYING STUPID THINGS

 

[lizard808uk]

From my experience many of the games that are over 16 megabit (2MB) are third party and have versions available for SNES. (where os9xgp can load up to 4mb / 32mbit roms).

Games you'd be missing out on would be stuff like Sonic 3D blast and Streets of Rage 3 - games that were released when the genesis was arguably on the way out. The real halcyon era for the genesis in my opinion was with games like streets of rage 2 and sonic 2/3 and codemasters games like pete sampras and micro machines.

I think the only "large" game I'd miss would be WWF Wrestlemania since the genesis version was streets ahead of the SNES version. Other than that I think people would be willing to leave these games in order to have full speed genesis emulation.

btw, sonic 3 and sonic/knuckles are both 2MB .smd files!

EDIT: If Rlyeh can do 4MB - I think we're going to have a competition on our hands to see who can do the best genesis emulation!

 

[Horscht]

WHAT THE HELL ARE U SAYING? ARE U CRAZY? IT WILL SUPPORT ROMS TILL 4 mb i'VE JUST ASKED RLYEH! DON'T LIE AND GET INFORMED BEFORE SAYING STUPID THINGS

STFU!

He´s talking about HIS emulator, nor Rlyhe´s. So you better have a closer look before psoting stupid things.

 

[Vimacs]

squide if you can do that that would be realy amazing!

WHAT THE HELL ARE U SAYING? ARE U CRAZY? IT WILL SUPPORT ROMS TILL 4 mb i'VE JUST ASKED RLYEH! DON'T LIE AND GET INFORMED BEFORE SAYING STUPID THINGS

go to hell....

 

[Drumaster]

WHAT THE HELL ARE U SAYING? ARE U CRAZY? IT WILL SUPPORT ROMS TILL 4 mb i'VE JUST ASKED RLYEH! DON'T LIE AND GET INFORMED BEFORE SAYING STUPID THINGS

Squidge is not Rlyeh, ok?!

But it's true I didn't know Squidge were at work on this too!
So it's great 'cause competition gives better results!

 

[GPJosh]

Sonic the Hedgehog and Raiden are both over 2 megs! Ouch! I love them both.

 

[GPnator]

WHAT THE HELL ARE U SAYING? ARE U CRAZY? IT WILL SUPPORT ROMS TILL 4 mb i'VE JUST ASKED RLYEH! DON'T LIE AND GET INFORMED BEFORE SAYING STUPID THINGS

ur a bit stupid?!

 

[Huxley]

Yeah, I'd rather have full speed + sound for the majority of games rather than all games at a slower speed.

Great work if you can do it, Squidge

 

[Tobriand]

Unfortunately, included in those 30 or so games (or maybe more - you've checked more than I have) is Phantasy Star 4, the main RPG I'd want a Gen emu for lol - and Beyond Oasis, another similar thing. They're 3mb. Which is waaaay more, I suspect, than you could possibly manage to hack away (litterally ). And I *doubt* they're padded to meet the 3mb size; I don't even know if games from that era *were* padded.

However.

If you could manage a no frameskip 100% speed with sound emu for even a fair few things at 2mb or less, you'd have accomplished more than all the genesis emu authors to date have for Gp32. At least, in the way of emus I know about. And if it ran everything at 2mb or less, that's most of the games for Genesis, full stop. Which is nice. Or better than nice, even. Perhaps brilliant would be better - or sensational

Bearing in mind Rlyeh's announced an ASM core for fGen that won't work quite at this speed, but I suspect won't have the same problems size-wise, what may end up happening is people using your one for most games, and his for the very few that are somewhat too big - which certainly wouldn't be a bad situation to be in. Indeed, it'd actually be a pretty great situation to be in.

Just a quick question, though? What is the Z80 actually used for? I think I remember someone saying it managed the sound, so if that's the case, would I be right in thinking that, theoretically, it might be possible to play games without sound - or at least, without Z80 emulation - larger than 2MB?

Admittedly, the chances are that the very games larger than 2MB are the ones where Z80 emulation is essential, but it might get a few of them working... Though which ones, I don't know...

Even if that wouldn't work, though, like I say, using fGen for larger roms and yours for everything else would be a brilliant situation to be in.

The very best of luck on managing it

 

[Drumaster]

What not joigning your skills to have a full speed with sound and 4 MB rom size Genesis emulator?

 

[Samuel]

Please I am very dissapointed with me, i missread the post
I'd like to be forgiven by you. Sorry

 

[Dolfhin]

I have just listed the roms that are over 2 MB and most of them aren't 'must-play' title's.
I'm downloading a few over 2 MB rom's right now to see if i can 'trim' (remove the 00000 at the end of the rom) them down. I hope it works

btw : 133 MHZ with sound!!!! Wow that's even more amazing than your GPDrive we should raise a shrine for Squide

 

[Tobriand]

Or even a single emu that detects romsize and determines which cores to use based on that - could be interesting, though I suspect the filesize would be huge...