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Mega Drive - Known Compatibility Issues

Posted: Tue May 05, 2015 6:17 am
by Nemesis
The list of known compatibility issues with Mega Drive games in Exodus is available here: ... lter=10200

If you've found a game that doesn't work in Exodus, check to see if it's already listed, and if it isn't, please make a post here and let me know, that way I can ensure it's tested and fixed in a later release. Thanks for any time you invest testing and reporting issues here, it's an essential step in improving emulation.

Posted: Tue May 05, 2015 6:19 am
by Nemesis
The following reports have been posted in another thread already, I'm listing them here for my reference as I still need to investigate them.
Shadow wrote:Killing game show: Black screen.

Mega-lo-Mania: Black screen.

Speedy Gonzales - Cheeze Cat-astrophe: no sound.

Strider II: no collision with enemies, immortality.

Shadow of the Beast: no collision with enemies.

The Lawnmower Man: flashing vertical stripes on 3d levels.
MetalliC wrote:I've noticed "Mr.Nutz Hoppin' Mad" won't work, both original and "fixed" versions hang at very start, sometimes after showing Sega logo.

Posted: Wed May 06, 2015 12:36 am
by Nemesis
Shadow wrote:Another World: minor problems with control on the title screen (Start \ Password)

Barkley Shut Up and Jam 2: shaking vertical stripes on the character select screen.

Barkley Shut Up and Jam: goes into a loop of resets on SEGA logo. (probably SRAM\EEPROM issue)

Battlemaster: run slowly (incorrect clearing of Z80 registers on a reset) Fixed in 8b374cd build.

Bugs Bunny in Double Trouble: hangs on the title screen.

Chess [Unl]: run slowly (incorrect clearing of Z80 registers on a reset) Fixed in 8b374cd build.

Decap Attack: run slowly (incorrect clearing of Z80 registers on a reset) Fixed in 8b374cd build.

Metal Sonic HYPERDRIVE: run slowly at title screen (48-60fps) and gameplay in fullspeed (incorrect clearing of Z80 registers on a reset?) Not fixed.

Talmit's Adventure: hangs in pause mode

Posted: Sat May 09, 2015 5:49 am
by 90s Gamer
Thanks Nemesis for the efforts you've put into the Exodus platform. Your accuracy-focused philosophy is greatly appreciated!

Here's a list of things I've found, using the No-Intro set:
*Monster World IV (Japan) // (USA, Europe) (En,Ja) (Virtual Console) - Crashes during the introduction.

*Wonder Boy in Monster World (USA, Europe) - Crashes after pressing start at title (I assume this has to do with SRAM).

*Kid Chameleon (USA, Europe) - Big framedrop.

*Sonic The Hedgehog 3 (USA) - Graphical glitches with Stage 1's water.

*Ayrton Senna's Super Monaco GP II (USA) (En,Ja) - Z80 (loop?) slows game significantly down. Disabling the Z80 results in lack of SFX.
I must add that I've encountered no problems with "Rockman - Mega World (Japan)".

"Mega Man - The Wily Wars (Europe)" and "Rockman - Mega World (Japan) (Alt 1)" do indeed crash as reported.

Re: Mega Drive - Known Compatibility Issues

Posted: Fri Nov 06, 2015 2:20 am
by ehw
For consistency, I noticed some of the compilation games won't load with Exodus. I tested Mega Games 10 in 1, and it seems that Sonic 1 and some other games won't run but games like Hang On will for some reason.

Re: Mega Drive - Known Compatibility Issues

Posted: Mon Mar 04, 2019 3:23 am
by mrcity
Great work on the emulator! This provides so many insightful tools into how Genesis games behave.

I did have one issue though: Pac-Man 2 would not load beyond the splash screen where Pac-Man winks at you. I'm not sure if this is due to some interrupts it throws that aren't being handled, or maybe some weird disassembly. I did notice that a lot of frames begin with "JMP 202" in the stack trace. Well, the disassembler shows an instruction it picked up on at 0x200 in ROM that's a lot longer than 2 bytes. :? Maybe that in & of itself doesn't cause a problem, but it could be getting confused elsewhere in some code running sequentially later on.

Re: Mega Drive - Known Compatibility Issues

Posted: Mon Mar 11, 2019 11:35 am
by Nemesis
Thanks for your feedback. Unfortunately there are more than a few games that have problems like this right now. Most of them that I've traced to date come back to the same thing, which is a lack of sub-opcode timing emulation. Without that, timing events in the system often appear from the CPU perspective to happen with the wrong timing, and therefore games which are sensitive to timing issues can malfunction. Rather than offset all the external timing events to make them appear to happen more closely to the correct timing, I want to properly support cycle-accurate sub-opcode timing in the 68000 CPU core. That's the next big thing I want to tackle with Exodus, but it's a big job, and there are bunch more hardware tests I need to do to confirm some timing behaviour before I add support for it.

If you only need to play the games, BlastEm is a very good recent emulator that has great support for a lot of precise timing cases and obscure VDP bugs and features. If you need the power of the Exodus debugging features though, you'll have to wait a bit longer until I can dedicate more time to get this known issue solved. After that, I'll hunt down and fix remaining game-specific issues, but at this point I'm not looking at them too closely anymore until I can address this big known issue.