Hi,
I opened near every model of Sega consoles (Megadrive,Saturn,Dreamcast,etc...), and on all there are some chips with the code that begins by 315-...
What does it means?
This means that's a Sega manufactured? or what else?
Because I also saw some IC's with this kind of code, didn't knew that some IC's could be "especially made for sega console".
Sega has always had good relationships with manufacturers of electronic components. JVC, NEC, Hitachi, and Sharp are among the companies who not only provide stock components like lenses and connectors, but customized integrated circuits as well. The chips you've identified are indeed custom components that do not generally appear in any other systems.
Other game companies also use custom chips. Sony has fabrication facilities that allow them to make chips to spec. Atari famously commissioned customized graphics chips for the Lynx and the Jaguar. And Nintendo's famous region lockout chips weren't exactly off-the-shelf technology either.
Ok thanks a lot :)