Picodrive 1.31


notaz

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Joined
Aug 23, 2005
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Location
Lithuania
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notaz.gp2x.de
Edit: figured out what was wrong with Batman games and fixed Lunar 2 bug. Download 1.31 at the bottom of this post.

I am a bit tired right now so here is a list of major stuff:

All hardware is emulated now
I added emulation for scaling/rotation chip, slows down the BIOS screen to a crawl, but Sonic CD special state is playable. Disabled by default, because very few games use it.

new option: ReadAhead buffer
This is to deal with slow SD card access in GP2X. It just assumes that data is sequential and reads more than it really needs, and later uses already read data. Very useful for FMV games. Try various settings and see which suits you best (I use 2048K). The downside is longer load times.

wait loop detection
Gives nice speedup for some games, but has no effect on most others. Sonic CD can be run underclocked now (well except past stages with PCM sound special stages with gfx chip).

zipped ISOs
Saves a lot of space but causes insane (several minute long) load times.

detailed changelog
  • ISO files now can be zipped. Note that this causes VERY long loading times.
  • Added data pre-buffering support, this allows to reduce frequency of short pauses in FMV games (caused by SD access), but makes those pauses longer.
  • Fixed PCM DMA transfers (intro FMV in Popful Mail).
  • Properly implemented "decode" data transformation (Jaguar XJ220).
  • Integrated "better sync" code into cyclone code, what made this mode much faster.
  • Fixed a bug related to game specific config saving.
  • Frameskipper was skipping sound processing, what caused some audio desyncs. Fixed.
  • Fixed reset not working for some games.
  • New assembly optimized memory handlers for CD (gives at least a few fps). Also re-enabled all optimizations from 0.964 release.
  • New idle-loop detection code for sub-68k. Speeds up at least a few games.
final thoughts
Well this project matured pretty well and I feel pretty satisfied with it. It was my main project for some time now, eating most my free-time-for-deving. So I think I had enough of this, this will be one of the last releases. It is still far from perfect, there are some compatibility issues, but it is not easy to finish these. I will still fix the obvious bugs, but not those which need all day of debugging, like the broken Batman games, for example. Hope all of you also had some fun with this thing. Thanks to all who donated (and to those who will), supported me and kept me motivated.

download 1.30
download 1.31
 
Last edited by a moderator:
This is awesome news!!

Thanks for all your hard work notaz, you're truly one of the greatest devs in the scene! :D

Now to go and test out this new release...looks like I won't be getting much sleep this weekend...;)
 
Awesome. Now I can play Sonic CD with the special stages! They run with minimal frameskip at 250mhz for me. (Doesn't seem to be slow on the BIOS like you said, though. Full 60fps for me.) Excellent work. This is one of my most used emulators on my 2X, and it looks like it's staying that way because it's brilliant.
 
how I miss my gp2x so much :~
can anyone say if final fight cd is playing fullspeed?

notaz, would it be possible to create a zip seek cache table for every 2kb, thus speeding up seek time while trying to read from a zipped iso?
or perhaps splitting the image file in smaller zip files so you don't have to use same dictionary for the whole iso?
 
It would be cool if you released the new code, I have an idea...

Then again, if you haven't changed Cyclone since 16/10/2006, it doesn't matter to me.
 
i agree with an above poster, i wish emulation of all systems was as good as picodrive. i believe it to be the most compatible, fastest, and problem-free emu on gp2x

thankyou for all your hard work over time, notaz. what's next? ;)
 
Great release, notaz! Thunderstrike and Jaguar are working!

Thunder1.jpg
Thunder2.jpg


Jaguar1.jpg
Jaguar2.jpg


Many thanks for all the hard work. I will miss the PicoDrive updates all a few weeks.
Good luck for all your next projects...

Regards,
Stephan
 
I never thought this emulator would come this far so quickly, you are certainly a hard working and impressive coder on the GP2X scene. I am rediscovering the Sega CD games from my youtha nd I am loving it! I am tired and have no time to donate tonight but I will do so tomorrow, you certainly deserve it.

PS: I am curious, what types of projects are you planning to work on in the GP2X scene in the near future?
 
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