
Left side open

Right side open

Drive bays

PSU Mounting location
Once you open the case up you can see why there is a PSU vent on the front of the case. The PSU is mounted on the front facing backwards instead of the rear of the case as tower cases tend to mount. There is an extension cord that leads out to the rear Power connector. This means that the power supply will blow air out of the front of the case instead of the rear of the case, hence the vent.

Rear fan

PSU extension

PSU cord

HDD bay
Next to the PSU position is where the drives are installed. There is the two 5.25" drive bays, the FDD drive bay and a 3.5" drive bay that is on the side of the 5.25" drive bays. This is where the internal HDD is installed. Note, that if you want, you can install another 3.5" hard drive in the FDD position instead of a FDD, as there is little use for FDDs today.
The motherboard tray can fit any micro-ATX or Full sized ATX motherboards. The IO area is below the PSU extension cord. Above the IO area is the space for two 80mm fans. There are seven full-height PCI slots to install expansion cards onto the motherboard. Note I have concerns on fitting any but the most basic cards in there as the space will be tight. It is a very elegant compromise that Cooler Master took in designing this case for both the desktop and Tower configuration.