Under the cover
Pull the cover, and you get a look at the P series' almost completely tool-free guts. There are custom tool-free drive rails, tool-free fasteners, and clever tool-free latching mechanisms to hold everything together.

At the top of the case are two internal 3.5" drive bays, complete with neatly pre-routed Serial ATA power and I/O connectors. These drives fit into drive rails that snap securely into place.

Drives living here, in one of the SB81P's three cooling zones, are cooled by the two upper fans at the rear of the case.

Here's a shot of the snap-in doohickey that secures the tray for external drives. Actually this fastener is a part of the 5.25" drive rails. Again, no screws are required.

The drive cage pops out for easy accessibility. The lower 3.5" bay will house either an external drive, like a floppy, or a 3.5" internal hard drive, but they mount different. Shuttle supplies rails for the floppy, while hard drives just snap into the bottom of the tray via a tension-based mechanism. This is the only location where an ATA/100 drive can live in the SB81P. The motherboard's single ATA port will serve both the 3.5" drive and the optical drive, as master and slave devices.