Moving to the top of the HC6800, there's nothing to look at but the curves of the molded case. From the back, just below the top, you'll see the two indicator lights (Power and Status) on the back center edge. This is due to the control panel being hidden behind a hinged door on the top that lifts from the back. The control panel will be discussed immediately below.
The inputs and outputs are located in the back, but are nicely recessed, and the projector comes with a cable cover, to help hide cabling. More on the inputs and outputs below.
The fan intake and exhaust are on the sides. Also, the left side (looking from the front) has the lamp door, to change out the lamp, and that means you don't have to unmount a ceiling mounted HC6800 to change it. My best guess is that more than half the home theater projectors still have to be unmounted because their lamp doors are on the bottom, where they get hidden by the ceiling mount.
The control panel is the usual affair. The larger power button (once for "on", press twice for "off"), is on the left. There is the typical four navigation arrow keys in a diamond configuration, with the Enter button in the center. In the upper right is the Lens Shift button, and a button that toggles between power zoom and power focus controls is in the lower right. The Menu button is on the bottom left.