At the rear of the ATG D620 is a single, heavy duty rubber flap which protects some of the ports. Behind the flap is a serial port, a D-SUB port, two USB 2.0 ports, a modem socket and an Ethernet port. Curiously the power socket isn't covered by the flap - I'm not sure if Dell thinks that it will somehow be exempt from dust ingress, but I'm fairly certain that it won't be.
On the right are two more USB 2.0 ports, which are also covered by a rubber flap. Bizarrely, the rubber cover for these two ports is not attached to the chassis and comes off completely. Why Dell has taken this approach is beyond me, since this small square of rubber is bound to be misplaced, especially if you're using the ATG outdoors.
Also on the right is a DVD-ROM/CD-RW combo drive. This is a removable unit and can be replaced with a DVD writer if needs be, or even with a second battery for maximum "on the go" time. Unfortunately, the drive supplied is a standard Dell model, with no additional protection, making it another point for dust and dirt to get into the machine.
On the left there are headphone and microphone sockets, which are curiously not protected in any way. Here you'll also find the PC Card and SmartCard slots, both of which are occupied by removable spacers.
Now, I appreciate that Dell is marketing the ATG D620 as a semi-rugged notebook, so there is an argument for ports not being covered, as well as the standard optical drive. However, when the company has gone to such lengths to cover (most) of the ports at the rear, it seems strange that other ports and connectors are left unprotected.
Dell provides two batteries with the ATG, one standard six cell and an extended nine cell. As with the standard D620, the extended battery sticks out at the front of the notebook creating an extension to the wrist wrest. Although I wasn't sure about this design when I first saw it last year, after extended use I warmed to it and now feel that it's a better solution to having the extended battery sticking out at the rear.