Yep, Moose, Starfox is 3D. The perspective-corrected triangles are placed and sized on the 2D screen based on a third co-ordinate (Z). Once you add that Z dimension to X and Y, it becomes 3D. (Graphically at least.)
If you're at 200,200,100 (X,Y,Z) and there's a missile at 200,200,300... You and that missile are still 200 units apart thanks to that third dimension.
Back on topic, I don't really see any way the CF, SD, etc slots could manage an effective bandwidth to be of assistance in gaming. 240x320x2 = 153,600 bytes per screen. Take that times 30fps and you'd need to pump 4,608,000 bytes per second from the card to the device, unless it was transmitted in a digital format. But then you still have all of the overhead of performing processing on the device's CPU and communicating information upstream to the card before it can send anything back. Possibly if the card acted like an ultra-smart game cartridge, doing all of the processing, and only needing to receive the input from the D-Pad, buttons and stylus to use for calculations... All the device would have to do then would be to draw the data on the screen and send those inputs. But to create such a card couldn't be cost effective.
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