referring to the fig3 the motherboard 100 includes a six pci slot pinhole layout 10 a ˜ 10 f and a two cnr slot pinhole layout 12 a and 12 b . however , since the size of the motherboard is fixed and also in light of the corresponding problems between the interface cards on the slots and motherboards , the positioning of slot placement is limited . since there are only 7 slots available for placement ( excluding the agp slot ), therefore , the number of slots used on the motherboard cannot be extended limitlessly . when forcing the pci slot pinhole layout 10 f and the cnr slot pinhole layout 12 b to co - function in the same slot position , an electrical shortage would thus result due to the overlap and connection between pinholes . fig4 is a magnified view illustrating a portion 400 of motherboard 100 , from which we can see the conflicts or connections between the pinhole rows 121 , 122 of cnr slot pinhole layout 12 b and the pinhole rows 101 , 102 of pci slot pinhole layout 10 f . hence , circuit boards having different slots are unable to co - function , and accordingly , diverse products corresponding to different extension slots are produced . fig5 illustrates the slot pinhole dual layout according to a first preferred embodiment in present invention . in the present invention , a dual pinhole layout 50 for slots is located at a portion 500 of a circuit board 100 , and includes a first pinhole layout 51 and a second pinhole layout 52 . there is another pinhole layout 12 a beside the first pinhole layout 51 that continues to use the same slot on the slot pinhole layout 52 , and can be used by the ever - present cnr slots . moreover , there is yet another pinhole layout 10 e beside the second pinhole layout 52 that continues to use the second pinhole layout on the same slot of the first pinhole layout 51 , and can be used by the pci slots . in order for the first pinhole layout 51 , the second pinhole layout 52 , and two pinhole layouts 10 e and 12 a to co - function in the limited space of the circuit board , the first pinhole layout 51 and the second pinhole layout 52 are closely aligned together so that the dual layout 50 are on a single slot . thus , depending on what is required , the user can easily select either the pci or cnr slot on the slot pinhole dual layout 50 . the first pinhole layout 51 includes the pinhole rows 511 , 512 , 513 , 514 ; the second pinhole layout 52 includes the pinhole rows 521 , 522 , 523 , 524 . each pinhole row is made up of a plurality of pinholes 530 , the pinhole rows 511 , 512 on the first pinhole layout 51 and the pinhole rows 521 , 522 on the second pinhole layout 52 can be aligned closely together without an overlap or connection between the pinholes 530 . therefore , the pinhole rows 521 , 522 on the second pinhole layout 52 are moved an appropriate distance , such as moving downward 55 , thereby widening the distance between the pinhole rows 511 and pinhole rows 512 on the first pinhole layout 51 . this also means that a certain distance is kept between the pinholes 530 of the pinhole rows 511 , 512 on the first pinholes layout 51 and those of pinhole rows 521 , 522 on the second pinhole layout 52 m , and are staggered orderly without causing overlap or connection between the pinholes 530 . when assembling the motherboard , as the use of cnr slots gradually increases as per the market demand , different pcbs would not need to be produced when applying the preferred embodiment of the present invention . rather , only custom - made slots need alterations , wherein the cnr slots are electrically connected to the second pinhole layout 52 of the slot pinhole dual layout 50 in the present invention . as the market demand for pci slots gradually increases , the pci slots merely need to be electrically connected to the first pinhole layout 51 of the slot pinhole dual layout 50 in the present invention without having to produce custom - made motherboards . even though custom - made pin header slots must be used when using the cnr slots , the required settings of the custom - made pin - headers and a new connector model slot for changing the pinhole position can be made to fit the pinhole layout . however , the production cost spent on the custom - made pin header slot and slot pinhole is much cheaper than that of producing two different circuit boards . therefore , in application , the present invention can greatly reduce production costs . in the present embodiment , since the number of pinholes on any of the pinhole rows on the second pinhole layout 52 is less than that of the first pinhole layout 51 , the pinhole rows 521 , 522 are moved onto the second pinhole layout to an appropriate distance , such as moving upward 55 . the pinhole rows 511 , 512 on the first pinhole layout 51 can also be moved in order to achieve the same result . fig6 illustrates the slot pinhole dual layout in the second preferred embodiment according to the present invention . the slot pinhole dual layout 60 is located at a portion 600 of a motherboard or circuit board 100 , and includes a first pinhole layout 61 and a second pinhole layout 62 ; the first pinhole layout 61 is made up of four pinhole rows and is suitable for continued use of the pci slot 66 , wherein each pinhole row is made up of a plurality of pinholes . the second pinhole layout 62 is also made up of four pinhole rows suitable for continued use of the cnr slot 68 , wherein each pinhole row also contains a plurality of pinholes . next , the slot pinhole dual layout 60 , merely needs to minimize the distance between the pinholes on the first pinhole layout 61 and those on the second pinhole layout 62 . thus , by keeping the first pinhole layout 61 and the second pinhole layout 62 close enough but not overlapped , over and above such advantages as the above - mentioned of continued use of the pci slot 66 and the co - functioning of the cnr slot 68 , it can also be easily color - coded , for example , the pci slot 66 is white , and the cnr slot 68 is cyan . fig7 illustrates the slot pinhole dual layout in the third preferred embodiment according to the present invention . the slot pinhole dual layout 70 is located at a portion 700 of a motherboard or circuit board 100 and the slot pinhole dual layout 70 includes a first pinhole layout 71 and a second pinhole layout 72 . the first pinhole layout 71 is made up of 4 pinhole rows and is suitable for continued use of the pci slot 76 . each pinhole row is made up of a plurality of pinholes ; the second pinhole layout 72 also has 4 pinhole rows and is suitable for continued use of the pci slot 78 , wherein each pinhole row is formed of a plurality of pinholes . the distance between the pinhole rows of the first pinhole layout 71 and those of the second pinhole layout 72 can be minimized to an appropriate value so that the first pinhole layout 71 and the second pinhole layout 72 are close enough but do not overlap for continued use of the complex slot 75 . in addition , a complex slot 75 using both the pci slot 76 and the cnr slot 78 has the advantages of choosing from the pci slot and the cnr slot , simultaneously keeping two different slots . nowadays , in the market for motherboards , customer demands for quantity and a combination of diverse extension slots are different , and there are conflicts between pci slots and cnr slots on the same slot layout . in order to satisfy the demands of different customers without spending too much time and money on producing two or more different products , so that every type of product can enter the market , it can be achieved by either moving the pin headers on the slots or making a new design . moreover , it achieves the usage of the same slot , which can provide two different interfaces after having the dual design slot layout . from the preferred embodiment described in the above , there are some advantages from applying the present invention , listed as following : 1 . the dual layout in the present invention can solve the problems of the limited size of motherboard ; and can also provide different slot styles to be chosen depending on market demand . 2 . the dual layout in the present invention can solve the problems between different generations of interface devices , and also the customers &# 39 ; diverse demands on the mainstream product and the transitional products . 3 . the application of the slot pinhole dual layout in the present invention can increase the usage of the same printing circuit board to facilitate the management of inventory stock and also serves to lower the cost of inventory stock . the present invention has been disclosed using an exemplary preferred embodiment . however , it is to be understood that the scope and the sprit of the invention is not limited to the disclosed embodiments ; on the contrary , it is intended to cover various modifications and similar arrangements . the scope of the claims , therefore , should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements .