Patent ID: 7894193

Claim:
A mechanism for saving space in a desktop computer, used for allowing a computer mainframe to occupy a small space, sand computer mainframe comprising: a) a rack having a back plate having: i) a predetermined number of groove holes; and ii) a plurality of back plate holes; b) a motherboard located in an interior of the rack and having a predetermined number of interface card slots, each of the predetermined number of groove holes of the back plate corresponding to one of the predetermined number of interface card slots of the motherboard and being used for installing an interface card; the predetermined number of groove holes of the back plate being at least two less than the predetermined number of interface card slots of the motherboard allowing at least two alternative interface slots of the predetermined number of interface card slots of the motherboard to be unused; c) a power supply electrically connected to the motherboard and having a plurality of power supply holes, and an outer end of the power supply extending outwardly from the back plate; and d) a rear supporting frame located on an exterior of the back plate and surrounding the outer end of the power supply, the rear supporting frame having a plurality of first holes located on a front surface thereof and a plurality of second holes being located on a rear surface thereof, the rear supporting frame being connected to both the outer end of the power supply and the exterior of the back plate; wherein a corresponding one of the plurality of first holes of the rear supporting frame is connected to a corresponding one of the plurality of power supply holes of the power supply, and a corresponding one of the plurality of second holes of the rear supporting frame is connected to a corresponding one of the plurality of back plate holes of the back plate, wherein the back plate has a first groove hole, the power supply is inserted into the first groove hole; the power supply occupies a space in the rack to correspond to at least one of the unused alternative interface slots.