To access to the interior, simply remove three thumbscrews, which will in turn allow you to slide the ISK 600's entire cover off. There are openings on both sides, so you can easily reach everything should the need arise. Every edge appears to be folded, which allows you to reach into the chassis without having to worry about incidental cuts.
While one side is a simple opening, the other may also hold a 3.5" hard drive. This toward the back of the chassis, in an area that would otherwise remain empty. While the inclusion of such a mounting possibility is nice, note that a large top-blow CPU cooler could get in the way of the slot.
Antec also included a tray for a second 3.5" drive in the top, so you have the flexibility to decide where to place such a unit. Use a tower cooler, though, and you will probably have to sacrifice the position in the top. A second tray in the front holds both the slimline ODD and two additional 2.5" drives. Both trays are lined with foam pads to ensure they stay in place, without passing on any vibrations.
To fit everything, Antec placed the PSU bay into the very front of the ISK 600. It is supposed to be installed with the fan facing toward the front, since the small air vents in the front panel allow for fresh air to be drawn into the PSU. There is ample foam lining as well to make sure the unit does not be cause any nasty vibrations. You can easily reach this position by removing the ODD tray above.
The aforementioned 120 mm fan comes with a firmly attached high/low switch. While the switch is a nice addition, you will have to remove the top cover to access the switch. An externally affixed switch would have been better. The ITX board's motherboard tray is nothing out of the ordinary, featuring the default stand-offs and a solid surface.
Before diving into the assembly process, let us take a quick look at the other cables inside. First off, there are the I/O leads. Oddly enough, the USB 3.0 plug, which only connects to the single connector in the front of the chassis, actually does come with a full 3.0 and 2.0 header. There is absolutely no reason for Antec not to offer two USB 3.0 ports instead of this mixture in generations since the proper cable to use either variant is there. Had Antec included two modern USB plugs, it would have even made one of these cables obsolete. The power, reset and LED cables are pretty standard, with the exception of the power LED cable. Here, Antec employed a fully sized Molex plug since the lighting element draws a lot of power and would otherwise cease working, while plugged straight into the motherboard's header. There is also the angled power plug - fairly compact, its only purpose is to route the connector from the font to the rear of the case.