MathewWi / wii-mednafen

Automatically exported from code.google.com/p/wii-mednafen
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Rewind support for Sega Genesis (v0.2) #21

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago
I was hoping you would include Sega Genesis with 0.1's rewind feature,but as 
you said rewinding is still in developement I did not expect it.

I know it is possible considering that there is an emulator called 
"Gens PLUS! Rewind" that provides quite a long amount of smooth rewind frames.

In closing,I hope you consider later on enabling rewind support for the Sega 
Genesis emulation.

Original issue reported on code.google.com by bennay...@gmail.com on 14 Jan 2012 at 2:42

GoogleCodeExporter commented 9 years ago
Clearly it is possible, as Mednafen does support rewind. However, as stated in 
the release notes:

"Due to the amount of memory and processing required, rewind support is
currently limited to the following emulators (GameBoy/GameBoy Color, Game Gear, 
Lynx, 
 Nintendo Entertainment System (excludes FDS games), Neo Geo Pocket, PC Engine/TurboGrafx 16 (excludes CD games), Sega Master System, WonderSwan (excludes large SRAM sizes: Dicing Knight, Judgment Silversword))"

Rewind takes a lot of overhead in terms of memory and processing. For each 
frame, it has to compress the state and store it. For emulators that are 
consuming close to all the resources (of the Wii) just to support emulation, 
there is not enough left to do the compression without interfering with the 
game's performance. Thus, the games run very choppy with frame skipping and 
slowdown. So, unless there is a major increase in the speed of Genesis 
emulation, rewind won't be enabled for the publicly released versions.

However, you are free to build it yourself and see how it performs. I added a 
flag so all you need to do is compile with ENABLE_MD_REWIND defined (in the 
Makefile). 

Original comment by raz0...@gmail.com on 14 Jan 2012 at 4:07

GoogleCodeExporter commented 9 years ago

Original comment by raz0...@gmail.com on 5 Feb 2012 at 4:20