It's this really cool thing that Extrems added to mplayer-ce a long time ago, it lets you render more pixels, in this case more than 640 horizontally so Genesis games that use a color border can display without any blurry scaling. A few Virtual Console games do it too. I added it to RA as a setting only for a few cores a while back but it's a bit glitchy (no overlays/menu transparency.)
Thanks, I think I have read a Dolphin article about this technique being used by Genesis VC emulator to render the overscan area but didn't understood why back then since Genesis Plus GX emulator doesn't use it while still being able to render colored borders around the active screen. Never noticed it was blurry with left/right borders enabled in this emulator but now you made me interested in trying your modified Retroarch version to see the difference.
Thanks.
I didn't originally know that endianess was the reason it wasn't on the Wii. Would also be nice to
use this on my Rebug CFW PS3.
Yes, Picodrive was initially not portable on big endian platforms as the code was designed for little-endian CPUs exclusively but, looking at the libretro github repository, it looks like some talented and motivated individual has picked up notaz work last years, apparently fixing 32x emulation bugs and also improving overall emulation accuracy, and eventually he ended up adding support for big-endian spme months ago, first targetting some PowerPC MAC platform apparently, which kinda automatically leaded to working support for Wii platform, thanks to Picodrive already being a libretro core and Retroarch already working on Wii. Last but not least, he wrote a PowerPC dynamic recompiler for the 32x CPUs from scratch, which greatly helps getting decent performance on Wii relatively slow CPU.
- Im not positive how accurate it is. In minimal testing, all 32x started & seemed to play full speed with no graphic issues, 10-12 games tested. I tried half dozen SG-1000 games, they all booted, but no video, only audio working on my side. Game Gear booted for me but 5-6 games i tested all had major graphics problems.
Picodrive does not emulate SG-1000 video modes neither Game Gear hardware (mostly extended color palette and extra START button) and will treat those games as Master System games, which would explain the issues you noticed.
