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Project Helix, the next XBOX console, is not expected to feature a disc drive
(news.instant-gaming.com)
This is a most excellent place for technology news and articles.
I've seen that case, where do the optical drives go? I didn't see a visible slot for them.
There's 2 ODD bays at the bottom. They're hidden by a plastic cover that pops on and off with magnets. It comes with a parts tray/drawer if you don't want drives in there.