As you can see, here I have installed a 3½" hard drive into the left 5¼" bay, with the optical drive mounted on the right. A floppy drive can be installed below the optical bay but the blank insert must be carefully cut out of the front plastic bezel with a sharp knife or razor. There are three different screw holes to allow for different mounting depths of the optical drive, so that the stealth eject button in the bezel will correctly come in contact with the actual drive. The door is spring loaded and will automatically open and shut with the movement of the tray.
Depending on the placement of some of the motherboard components, you may run into an interference issue with the overhang from the rear of the drives. Almost certainly you'll need to leave the drive cage out until you have everything else installed. The main ATX power connector is a 20+4 pin design with tabs to hold the optional 4-pin section in place. There is also a 4-pin +12v power for the CPU, and two other cables for the drives. The two SATA connectors are thoughtfully on separate cables, allowing one side for the floppy and optical and the other for a hard drive. There is no PCIe power connector, but most likely you won't find any half-height video cards that require one.
Even a micro-ATX AMD board with stock processor heatsink and cooling fan is a tight fit for this case. You'll need to be careful with cable routing to avoid getting pinched under the drive cage or stuck in a fan blade, and keeping the wires as neat as possible will ensure optimal cooling capability. Although I'm just using the onboard graphics in this install, users may want an add-in card for the extra video processing capability, particularly if you plan on doing any gaming or watching high definition video.
Although the vented section over the CPU fan isn't precisely centered, with the variance in motherboard socket placement it would be impossible to account for all possibilities. It is sufficient to provide a path for cooler air to enter the case, drawn in by the fan and then expelled either by the power supply or out the rear vents of the case. If using an add-in video card I would definitely suggest placing a 60mm intake fan in the left side to draw in cool air for it as well, particularly if the card uses a passive heatsink, as many half-height cards do.