Abstract:
An apparatus to allow a computer system board to automatically identify the chassis in which the system board is installed. The apparatus includes a) at least one conducting pad on the system board, b) at least one spring action grounding clip on the chassis, and in contact with the at least one conducting pad, and c) a logic circuit connected to the at least one conducting pad.

Description:
TECHNICAL FIELD 
     This disclosure relates to the field of computer systems, and, more particularly, to apparatus and methodologies for determining whether a personal computer system board has been installed in the correct personal computer chassis. 
     BACKGROUND 
     A personal computer system board needs to recognize whether it is installed in the correct personal computer chassis. Such recognition is necessary because the system board functions differently depending on the type of chassis. Previously, encoded riser cards or jumper settings were used to determine whether the system board was installed in the correct computer chassis. However, these methods have either become obsolete or are not efficient. Accordingly, what is needed is an apparatus and a methodology for automatically determining whether a system board has been installed in the correct type of computer chassis. 
     SUMMARY 
     The present disclosure describes an apparatus and a method to allow a computer system board to automatically identify the personal computer chassis in which the system board is installed. The apparatus includes a) at least one conducting pad on the system board, b) at least one spring action grounding clip on the chassis, and in contact with the at least one conducting pad, and c) a logic circuit connected to the at least one conducting pad. The method includes the steps of a) attaching at least one spring action grounding clip to the chassis, b) incorporating at least one conducting pad into the artwork of the printed wire assembly on the system board, c) connecting at least one conducting pad to a logic circuit on the system board, d) installing the system board in the chassis, and e) ensuring that at least one spring action grounding clip contacts at least one conducting pad. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partial cross-sectional view of a preferred embodiment. 
     FIG. 2 is a bottom view of a system board. 
     FIG. 3 is a top view of a computer chassis with one grounding clip. 
     FIG. 4 is a top view of a computer chassis with two grounding clips. 
     FIG. 5 is a schematic of a logic circuit on the system board. 
    
    
     DETAILED DESCRIPTION 
     Referring to FIG. 1, an assembler attaches a spring action grounding clip  1  to a predetermined position on a computer chassis  3 . A designer incorporates a conducting pad  4  into the artwork of the printed wire assembly on a corresponding position op the bottom side of a system board  5 . The conducting pad  4  connects to a logic circuit  6  on the system board  5 . The assembler then installs the system board  5  in the computer chassis  3 , so the spring action grounding clip  1  makes contact with the conducting pad  4  on the system board  5 . Contact between the spring action grounding clip  1  and the conducting pad  4  causes a short circuit to ground, resulting in an output of logical zero on the logic circuit  6  (FIG.  5 ). 
     FIG. 2 illustrates a potential arrangement of conducting pads  4  on the bottom side of the system board  5 . The designer incorporates three conducting pads  4  into the artwork of the printed wire assembly on the bottom side of a system board  5 . The location of the conducting pads  4  on the system board  5  corresponds to the possible attachment sites  7 ,  8 , and  9  of the spring action grounding clips  1  on the computer chassis  3 . 
     Referring to FIGS. 3 and 4, the computer chassis  3  has three possible attachment sites  7 ,  8 , and  9  for the spring action grounding clips  1 . Depending on the type of chassis to be identified, the assembler may be instructed to attach spring action grounding clips  1  to some, all, or none of the attachment sites  7 ,  8 , and  9 . With multiple possible attachment sites  7 ,  8 , and  9  to n (where n equals the number of possible attachment sites), different chassis types may be identified using a preferred embodiment. The number of attachment sites may vary depending on the number of possible chassis types to be identified. 
     FIG. 3 illustrates a potential arrangement of spring action grounding clips  1  on the computer chassis  3 . Referring to FIG. 3, the assembler attaches the spring action grounding clip  1  to the computer chassis  3  at attachment site  7 . The attachment of the spring action grounding clip  1  to the computer chassis  3  at attachment site  7  could correspond to a tower chassis. 
     FIG. 4 illustrates another potential arrangement of spring action grounding clips  1  on the computer chassis  3 . Referring to FIG. 4, the assembler attaches the spring action grounding clips  1  to the computer chassis  3  at attachment sites  7  and  8 . The attachment of the spring action grounding clips  1  to the computer chassis  3  at attachment sites  7  and  8  could correspond to a desktop chassis. 
     Referring to FIG. 5, the reference numeral  10  designates, in general, one embodiment of a computer for implementing the above described systems and methods. The computer  10  includes the spring action grounding clip  1 , the chassis  3 , the conducting pad  4 , the system board  5 , and the logic circuit  6 . The system board  5  may also include various system components such as one or more processors  12 , one or more storage devices  14 , and one or more input/output devices  16  including a monitor  16   a  and a keyboard  16   b.  The computer  10  further includes the necessary power circuitry (not shown) connectable to a power supply  18  for receiving operating power. The power supply  18  includes a ground receptacle for supplying a ground voltage to the chassis  3 . 
     In the computer  10 , the presence of the spring action grounding clip  1  on the computer chassis  3  causes a short circuit to ground, and an output of logical zero on the logic circuit  6 . In the absence of the spring action grounding clip  1 , no short circuit to ground occurs, and the logic circuit  6  registers an output of logical one. Each conducting pad  4  has a separate logic circuit  6  associated with it. Accordingly, the output of the logic circuits  6  varies depending upon the presence or absence of spring action grounding clips  1  within the various attachment sites  7 ,  8 , and  9 . 
     The varying outputs on the logic circuits  6  enable the system board  5  to recognize whether the system board  5  is installed in the correct computer chassis  3 . The system board  5  compares the outputs of the logic circuits  6  with a look-up table in a memory of the system board  5 . The look-up table indexes the logic circuit outputs corresponding to each particular chassis type. If the outputs of the logic circuits  6  correspond to the designated chassis in the look-up table, the system board  5  is installed in the correct computer chassis  3 . If the outputs of the logic circuits  6  do not correspond to the designated chassis in the look-up table, the system board  5  is not installed in the correct computer chassis  3 . 
     Although illustrative embodiments have been shown and described, a wide range of modification, changes and substitution is contemplated in the foregoing disclosure. In some instances, some features of the disclosed embodiments may be employed without a corresponding use of the other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.