Using the partslist below I would build a computer inside of an original nintendo entertainment system case. the start and reset buttons on the front of the case could be connected to standard case switches, the power and HDD led could be assigned to a single multi-colored LED mounted in the original LED socket. The motherboard is mounted on the inside of the case by using a dremel tool to carve grooves into 4 of the 6 struts that hold the case closed. The harddrive is mounted on a plexiglass structure built under the motherboard mounts and secured using the original screw mounts for the original electronics. The motherboard is then slid into place over the harddrive and mounted using another custom built plexiglass plate that secures the edge of the motherboard against the left side of the NES case and is screwed down to the original mounting posts. the left side of the NES case will have I/O port holes drilled to allow for access to the rear motherboard I/O ports. To allow space for the DVD drive the original heatsinks for the processor and chipset will be replaced with the ones listed in the parts list. The DVD drive (a slimline slot loading drive) will be mounted on the top half of the case and positioned so that the disks will eject through the original cartridge slot. The DVD drive will need to be mounted using a combination of plexiglass structure and JB Weld industrial adhesive. There will be an 80mm fan positioned on the right side of the case pointed to the left to provide airflow for the motherboard and HDD. All of these parts will be supplied power by a PicoPSU 120W Power supply mounted on top of the 24pin ATX connector.
With a 2.5" HDD I will be able to place the motherboard much lower in the case, to be able to fit he DVD drive properly.
ZOTAC IONITX-D-E Intel Atom N330 Dual Core 1.6 GHz
VIZO VIZO-NBC-101-CPR Copper Sleet Chipset Cooler
ZEROtherm ATOM 30H Low-Profile cooler for ITX, MATX, HTPC
2 x Kingston 2GB DDR2 667Desktop Memory Model KVR667D2/2GR (low profile)
LITE-ON Slot Load Slim CD/DVD Burner Black SATA Model DL-8ATS
1ST PC CORP. Slimline SATA Cable with 24" Serial ATA Female and 12" molex Power Connector
SILVERSTONE RL-FM81 80mm Case Fan
HITACHI Travelstar 7K320 320GB 7200 RPM 2.5" SATAII HDD
PicoPSU-120 12V DC-DC ATX power supply