Patent Publication Number: US-2004059856-A1

Title: Bus slot conversion module

Description:
BACKGROUND OF INVENTION  
       [0001] 1. Field of the Invention  
       [0002] The present invention relates generally to computer system architecture, and more specifically to computer system bus architecture. Even more specifically, the present invention relates to communications between a computer system bus and peripheral devices.  
       [0003] 2. Discussion of the Related Art  
       [0004] Computer system designs are typically structured so that a number of components are coupled directly or indirectly with a computer system&#39;s backplane. For example, microprocessors, random access memory (RAM) modules and BIOS ROM modules, and other components including printers, scanners, disk drives and optical drives (e.g., CD ROM dives and DVD Drives).  
       [0005] Typically expansion slots in the backplane provide an interface for peripherals to communicate with components coupled with the backplane. One system for organizing expansion slot communications between the backplane and peripherals is the Peripheral Component Interconnect (PCI) system. The PCI system is an interconnection system that supports both a newer PCI slot configuration, and in many designs, an older Industry Standard Architecture (ISA) slot configuration. Backplanes, however, are typically designed to include several PCI slots because the PCI system has a more modern and advantageous design, allowing, e.g., “plug and play” capability; thus, a PCI slot is often available for use.  
       [0006] Many peripherals, e.g., disk drives, and optical drives, however, are designed to couple with Integrated Drive Electronics (IDE) slots or Small Computer System Interface (SCSI) slots and cannot directly connect with PCI slots.  
       SUMMARY OF INVENTION  
       [0007] In one embodiment, the invention can be characterized as a bus slot conversion module including a canister comprising a first frame bracket and a front panel wherein the first frame bracket is coupled with the front panel wherein the first frame bracket is configured to support a first peripheral, wherein the front panel is configured to couple with a front side of a chassis. The bus slot conversion module also includes a conversion portion comprising a first PCB board wherein the first PCB board is coupled to the first frame bracket and a first peripheral slot, the first PCB board comprising traces that interconnect the first peripheral slot and a bus slot connector coupled with the first PCB board. The first peripheral slot is configured to couple with the first peripheral, and the bus slot connector is configured to couple with a bus slot wherein the first peripheral slot comprises a different pin configuration than the bus slot. The bus slot is coupled with a backplane, and the backplane is within the chassis.  
       [0008] In another embodiment, the invention can be characterized as a method for using peripherals with an incompatible bus slot. The method including steps of inserting a first peripheral in a first peripheral dock of a canister wherein the first peripheral dock comprises a first frame bracket wherein the first peripheral is guided by the frame bracket and a front panel wherein the frame bracket is coupled with the front panel, coupling the first peripheral with a first peripheral slot coupled to a first PCB board wherein the first PCB board is coupled to the first frame bracket, wherein a bus slot connector is coupled to the PCB board wherein the first PCB board interconnects the first peripheral slot with the bus slot connector, placing the canister into a chassis wherein the chassis houses a backplane, and coupling the bus slot connector with a bus slot wherein the bus slot is coupled to the backplane, and wherein the first peripheral slot comprises a different pin configuration than the bus slot. 
     
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
     [0009] The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein:  
     [0010]FIG. 1 is a functional block diagram illustrating interaction between a bus slot conversion module and a computer backplane;  
     [0011]FIG. 2 is a schematic view of one embodiment of the bus slot conversion module of FIG. 1;  
     [0012]FIG. 3 is a flow chart describing the steps traversed by a user when implementing the bus slot conversion module of FIG. 2;  
     [0013]FIG. 4A and FIG. 4B are perspective views of one embodiment of the bus slot conversion modules of FIGS. 1 and 2;  
     [0014]FIG. 5 is a view taken along line A-A in FIG. 4A illustrating features of the first PCB board;  
     [0015]FIG. 6 is a view taken along line B-B in FIG. 4B illustrating features of the second PCB board;  
     [0016]FIG. 7 is a perspective view of the bus slot conversion module of FIG. 4B with the second PCB board removed;  
     [0017]FIG. 8 is a perspective view of the bus slot conversion module of FIG. 4A with the first PCB board removed;  
     [0018]FIG. 9 is a view of the bus slot conversion module of FIG. 7 with the first peripheral removed;  
     [0019]FIG. 10 is a view of the bus slot conversion module of FIG. 9 with the lower frame bracket removed;  
     [0020]FIG. 11 is a view of the bus slot conversion module of FIG. 9 with the second peripheral removed;  
     [0021]FIG. 12 is a rear view of the bus slot conversion module of FIG. 4A;  
     [0022]FIG. 13 is a rear view of the bus slot conversion module of FIG. 4A;  
     [0023]FIG. 14 is a rear view of first and second PCB boards of FIGS. 4 through 13 and one embodiment of interconnections there between; and  
     [0024]FIGS. 15A and 15B are perspective views of one embodiment of the rear transition module of FIG. 2. 
    
    
     [0025] Corresponding reference characters indicate corresponding components throughout the several views of the drawings.  
     DETAILED DESCRIPTION  
     [0026] The following description is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined with reference to the claims.  
     [0027] Referring first to FIG. 1, shown is a functional block diagram illustrating interaction between a bus slot conversion module  100  and a computer backplane  102 . Shown are the bus slot conversion module  100 , the computer backplane  102 , a backplane bus  104 , a first peripheral  106 , a second peripheral  108 , a bus slot  110 , a conversion portion  112 , and a canister  114 .  
     [0028] The backplane  102  is shown coupled with the backplane bus  104 , and the backplane bus  104  is coupled with the bus slot  110 . The bus slot conversion module  100  is shown adjacent to the backplane  102 , and shown as part of the bus slot conversion module  100  is the canister  114 . Shown coupled to the canister  114  are the conversion portion  112  and the first and second peripherals  106 ,  108 . Also shown is the conversion portion  112  coupled to the first and second peripherals  106 ,  108 .  
     [0029] In several embodiments, the backplane  102  is part of a rack mounted computer system, e.g., a server farm system. The backplane  102  may be any industry standard backplane. In some embodiments, for example, the backplane  102  is compliant with a PCI Industrial Computer Manufacturers Group (PICMG) 2.16 standard. In these embodiments, as one of ordinary skill in the art recognizes, the bus slot  110  is a compact PCI slot and the backplane bus  104  is a PCI backplane bus. It should be recognized, however, that the bus slot  110  need not be a compact PCI bus slot and may be, for example, a full size PCI bus slot.  
     [0030] The conversion portion  112  according to several embodiments provides a mechanical and electrical conversion from the bus slot  110  to peripheral connectors utilized by the first and second peripheral devices  106 ,  108 . In several embodiments, for example, the bus slot  110  is a compact PCI slot and the first and second peripherals  106 ,  108  have Single Connection Attachment (SCA) connectors. In these several embodiments, the conversion portion  112  has a compact PCI connector for coupling with the compact PCI slot on the backplane  104 , and the conversion portion also has SCA slots for coupling with SCA connectors of the first and second peripherals  106 ,  108 . Thus, the conversion portion  112  provides a mechanical transition from a compact PCI slot to an SCA slot. In addition, the conversion portion  112  provides electrical conversion and coupling to interconnect the peripheral slots with the bus slot  110  so the first and second peripherals may communicate with the backplane  102  over the bus slot  110 .  
     [0031] The canister  114  according to several embodiments houses the first and second peripheral and provides mechanical support to the conversion portion  112 . In some embodiments, for example, the canister  114  includes printed circuit boards that are coupled to a frame infrastructure to form a rectangular canister which surrounds the first and second peripherals  106 ,  108 . According to several embodiments, the canister  114  is configured to be placed in a rack-mountable chassis, and to couple with the bus slot  110  on the backplane  102 . In many embodiments, the canister  114  is configured so that the first and second peripherals  106 ,  108  are readily removable from the canister  114  while the canister remains in the rack mountable chassis.  
     [0032] The first and second peripherals  106 ,  108  may be any type of storage device, e.g., floppy drives, disk drives, compact disk drives, or digital video disk (DVD) drives. In practice, according to several embodiments, the backplane  102  is part of a computer system that is located within a rack mounted chassis, and the canister  114  in several embodiments is inserted in an available slot of the rack mounted chassis. The first and second peripherals  106 ,  108  are placed within the canister  114  and coupled by the conversion portion  112  to the bus slot  110 . In this way, the first and second peripherals  106 ,  108  are communicatively coupled with the backplane  102 , and hence, other components coupled with the backplane  102 .  
     [0033] Referring next to FIG. 2, shown is a schematic view of one embodiment of the bus slot conversion module of FIG. 1. Shown are a bus slot conversion module  200 , a rack  202 , a chassis  204 , an available chassis slot  206 , a backplane  208 , a bus slot  210 , a canister  212 , a first peripheral dock  214 , a second peripheral dock  215 , a rear transition module  216 , a rear printed circuit board  218  (hereinafter referred to as a rear PCB board  218 ), a rear transition panel  220 , a rear bus slot connector  222 , rear horizontal peripheral slots  224  and rear vertical peripheral slots  226 .  
     [0034] The chassis  204  is located within and coupled to a bottom portion of the rack  202 . Within and coupled to the chassis  204  is the backplane  208 , and within the chassis is the available chassis slot  206 . Also shown adjacent to the chassis  204  and at a front side of the chassis  204  is the bus slot conversion module  200  that includes the canister  212 . Within the canister  212  are the first and second peripheral docks  214 ,  215 . The rear transition module  216  is shown outside the chassis  204  in position to be placed in the chassis  204  from a rear side of the chassis opposite to the bus slot conversion module  200 .  
     [0035] While referring to FIG. 2, simultaneous reference will be made to FIG. 3 which is a flow chart showing steps traversed by a user when implementing the bus slot conversion module  200 .  
     [0036] The rear transition module  216  is shown with the rear PCB board  218  coupled the rear panel  220 . Coupled with the rear PCB board  218  are the rear bus slot connector  222  and rear vertical peripheral slots  226 . Coupled with the rear panel  220  are the rear horizontal slots  224 .  
     [0037] As shown in FIG. 2, the rack  202  supports the chassis  204  that houses the backplane  208  and the bus slot conversion module  200  (when inserted in the chassis  204 ). The chassis  204 , according to several embodiments, is mounted with the rack  202  and provides a convenient platform for housing and interconnecting components of, for example, a server system.  
     [0038] The available chassis slot  206  is an unoccupied portion of the chassis  204  which is available for several different types of components, e.g., switching modules, power modules, and in several embodiments, the bus slot conversion module  200 .  
     [0039] The bus slot conversion module  200  according to several embodiments is designed to detachably mount and to fit within the available chassis slot  206 . As discussed further herein with reference to FIG. 4A, the bus slot conversion module  200  includes a bus slot connector, e.g., a compact PCI slot connector, that couples with the bus slot, e.g., a compact PCI slot, located on the backplane  208 .  
     [0040] In the present embodiment, the canister  212  of the bus slot conversion module  200  forms the first and second peripheral docks  214 ,  215  that are configured to provide a platform for peripherals, e.g., media storage peripherals, to detachably mount within the canister  212 . Within each of the first and second peripheral docks  214 ,  215  of the canister  212  is a peripheral slot (not shown), e.g., a SCSI slot, for coupling with a peripheral connector, e.g., a SCSI connector, of an inserted peripheral, e.g., the first peripheral  106  or the second peripheral  108 .  
     [0041] In practice, at least one peripheral is inserted into one of the first or second peripheral docks  214 ,  215  in the canister  212  (Step  302  of FIG. 3). As the at least one peripheral is inserted into the canister  212  the at least one peripheral is coupled with a peripheral slot, e.g., a Single Connection Attachment (SCA) slot within the canister  212  (Step  304  of FIG. 3). Next, the bus slot conversion module  200  is inserted into the available chassis slot  206  and the bus slot connector, e.g., a compact PCI slot connector (not shown), couples with the bus slot, e.g., a compact PCI slot, located on the backplane  208  (Steps  306  and  308  of FIG. 3). In this way, the peripheral slots within the canister  212  become coupled with the bus slot  210 . Thus, peripherals, e.g., SCSI peripherals, that are not compatible with the bus slot  210 , e.g., a PCI slot, may communicate with the backplane  208 , and hence, components coupled with the backplane  208 .  
     [0042] It should be recognized that peripherals need not be inserted in the canister  212  prior to placing the bus slot conversion module  212  in the available chassis slot  206 . In several embodiments, peripherals are hot swappable and may be inserted and removed after the bus slot conversion module  212  is within the chassis  204  and coupled with the backplane  208 .  
     [0043] Advantageously, the bus slot conversion module  212  provides a very simple expansion of the backplane&#39;s I/O slots, and a conversion from a pin configuration of the bus slot  210 , e.g., a compact PCI slot pin configuration to a pin configuration of a peripheral slot, e.g., a Single Connection Attachment (SCA) slot pin configuration, that couples with a peripheral within the canister  212 . Specifically, there is no need to cut or otherwise modify the backplane  208 ; instead, the bus slot conversion module  200  is simply inserted into the available slot  206  of the chassis  204  until a bus slot connector of the bus slot conversion module  212  detachably couples with the bus slot  210  on the backplane  208 . In this way, the bus slot conversion module  200  provides a universal transition from any industry standard backplane bus, e.g., PCI bus, to peripherals in the canister  212 . Additionally, in several embodiments, the bus slot conversion module  200  is a modular building block. For example, several bus slot conversion modules  200  may be coupled with the backplane  208  and controlled as a redundant array of independent disks (RAID); thus, providing a very flexible data storage entity with enhanced performance and data integrity.  
     [0044] In some embodiments, the bus slot conversion module  200  is used in conjunction with the rear transition module  216 . The rear transition module  216  according to several embodiments is designed to fit within a rear slot of the chassis  204  so a user may couple the rear transition module to a rear portion of the bus slot  210  (Step  310 ). The rear bus slot connector  222 , e.g., a compact PCI connector, is configured to couple with a rear portion of the bus slot, e.g., a compact PCI slot. When the rear transition module  216  is completely inserted within a rear part of the chassis  204 , the rear horizontal peripheral slots  224 , e.g., Single Connection Attachment (SCA) slots, are exposed to an outside area of the chassis  204 , i.e., the horizontal peripheral slots  224  are accessible from outside of the chassis  204  at the rear of the chassis  204 . Thus, the rear transition module  216  provides a conversion from a bus slot of one type of pin configuration to multiple peripheral slots of a second type of pin configuration that are accessible from the rear of the chassis  204 . A user may then simply couple one of the horizontal peripheral slots  224  to an external device (Step  312 ).  
     [0045] The rear vertical peripheral slots  216 , however, provide access to the rear transition module  216  from within the chassis (when the rear transition module is inserted in the chassis.) Advantageously, the rear horizontal peripheral slots  224  of the rear transition module  216  allow interconnections to be made from the backplane  208 , through the rear transition module  216  to a second chassis in another rack or to other peripherals. Thus, a user may optionally extend the backplane  208  so that the backplane  208  is connectable from a rear of the chassis  204 .  
     [0046] Beneficially, the rear transition module  216  also allows the bus slot conversion module  200  to communicatively couple with other devices coupled to the backplane  208  when the bus slot conversion module  200  would not ordinarily be able to do so. For example, some backplanes do not have traces to each of the pins of an available bus slot, and thus, the available bus slot cannot operationally couple peripherals in the bus slot conversion module  200  to other components coupled with the some backplanes. The rear transition module  216 , when coupled with the backplane  208  behind the bus slot conversion module  200 , provides interconnects between the bus slot  210  (which is coupled to the bus slot conversion module  200 ) and the rear vertical peripheral slots  226 , and the rear vertical peripheral slots  226  can be coupled to other components, e.g., a single board computer (SBC).  
     [0047] It should be recognized, however, that in several embodiments, the rear transition module  216  is not required and provides additional functionality to the bus slot conversion module  200  at a user&#39;s option.  
     [0048] Referring next to FIG. 4A, shown is a perspective view of one embodiment of the bus slot conversion modules of FIGS. 1 and 2. Shown is a bus slot conversion module  400 , a front panel  402 , a first peripheral face plate  404 , a second peripheral face plate  406 , a first printed circuit board  408  (hereinafter referred to as the first PCB board  408 ) and a bus slot connector  410 .  
     [0049] The first PCB board  408  is coupled to the front panel  402  and the bus slot connector  410 . The first and second peripheral face plates  404 ,  406  are arranged in tandem and coupled to the front panel  402 .  
     [0050] The first and second peripheral face plates  404 ,  406  are each coupled to a respective first and second peripherals, e.g., the first and second peripheral  106 ,  108 , that are obstructed from view in FIG. 4A. The first and second peripheral face plates  404 ,  406  function to both detachably couple the first and peripherals to the front panel  402  and provide a user interface, e.g., a handle, for a user to hold while, e.g., installing the first and second peripherals in the bus slot conversion module  400 .  
     [0051] The first PCB board  408  according to several embodiments provides electrical interconnects from the bus slot connector  410  to a first peripheral slot and to other interconnects that couple with a second peripheral slot. As discussed further with reference to FIG. 5, in several embodiments, the electrical interconnects on the first PCB board  408  from the bus slot connector  410  to the first peripheral slot provide a conversion from a pin arrangement of the bus slot connector  410 , e.g., a compact PCI connector pin arrangement, to a pin arrangement of the first peripheral slot, e.g., a SCA pin arrangement. Thus, in several embodiments, the first PCB board  408  is part of a conversion portion, e.g., the conversion portion  112 , of the bus slot conversion module  400 .  
     [0052] The bus slot connector  410  in several embodiments is a compact PCI connector that couples with a compact PCI slot on a computer backplane, e.g., the backplane  210 .  
     [0053] In practice, as discussed with reference to FIG. 2, the bus slot conversion module  400  is inserted within a rack mountable chassis, e.g., the chassis  204 , so that the bus slot connector  410  couples with a bus slot, e.g., bus slot  210 , on a backplane, e.g., backplane  208 .  
     [0054] Referring next to FIG. 4B, shown is another view of the bus slot conversion module  400  of FIG. 4A. Shown is the bus slot conversion module  400 , including the front panel  402 , the first PCB board  408 , the bus slot connector  410 , a first peripheral slot  412 , a second peripheral slot  414 , and a second printed circuit board  416  (herein after referred to as the second PCB board  416 ).  
     [0055] The second PCB board  416  is coupled with the second peripheral slot  414  and the front panel  402  and is arranged substantially parallel to the first PCB board  408 . The first and second PCB boards  408 ,  416  are separated by a space that is maintained in part by the front panel  402 . The space allows a first and second peripherals, e.g., the first and second peripherals  106 ,  108  to fit between the first and second PCB boards  408 ,  416 . Coupled with the first PCB board  408  are the first peripheral slot  412  and the bus slot connector  410 .  
     [0056] The second PCB board  416  provides electrical interconnects from pins of the second peripheral slot  414  to interconnects that, as discussed further with reference to FIGS. 6 and 14, lead to interconnects that span across the space between the first and second PCB boards  408 ,  416  to couple with the first PCB board  408 . The interconnects that span the space between the first and second PCB boards  408 ,  416  couple with interconnects on the first PCB board  408  that couple with pins of the bus slot connector  410 . Thus, in several embodiments, the second PCB board  416  and the first PCB board  408 , along with interconnects that couple the first and second PCB boards  408 ,  416  are part of a conversion portion, e.g., conversion portion  112 , of the bus slot conversion module  400  that converts a pin arrangement of the bus slot connector  410  so that it matches pin arrangements of the first and second peripheral slots  412 ,  414 .  
     [0057] Additionally, the first and second PCB boards  408 ,  416  make up part of a canister, e.g., canister  212 , of the bus slot conversion module  400 . Specifically, in some embodiments, outside surfaces of the first and second PCB boards  408 ,  416  form respective outer surfaces of the bus slot conversion module  400  wherein peripherals are interposed between the first and second PCB boards  408 ,  416 .  
     [0058] The first peripheral slot  412  and the second peripheral slot  414  in several embodiments are single connector attachment (SCA) slots for coupling with peripherals that have SCA connectors, e.g., the first and second peripherals  106 ,  108 .  
     [0059] In other embodiments, the first peripheral slot  412  and the second peripheral slot  414  are integrated drive electronics (IDE) slots for coupling with IDE compatible peripherals.  
     [0060] In practice, according to several embodiments, a first and/or second peripheral, e.g., hard drives, CD ROM drives, floppy drives and/or DVD drives, are inserted in the bus slot conversion module  400  through the front panel  402 . The first and second peripheral slots  412 ,  414  are situated at an opposite end of the front panel  402  to respectively couple with first and second peripherals when the first and second peripherals are completely inserted within the bus slot conversion module  400 .  
     [0061] Referring next to FIG. 5, shown is a view taken along line A-A in FIG. 4A illustrating features of the first PCB board  408 . Shown are the first PCB board  408 , a front edge  502  of the first PCB board  408 , a rear edge  504  of the first PCB board  408 , a first peripheral portion  506  of the first PCB board  408 , a second peripheral portion  508  of the first PCB board  408 , the first peripheral slot  412 , and the bus slot connector  410 .  
     [0062] The first peripheral slot  412  is coupled to the first PCB board  408  near the rear edge  504  of the first PCB board  408  and within the first peripheral portion  506  of the first PCB board  408 , and the bus slot connector  410  is coupled to the first PCB board  408  near the rear edge  504  of the first PCB board  408  within the second peripheral portion of the first PCB board  408 .  
     [0063] The first PCB board  408  supports the first peripheral slot  412  and the bus slot connector  410 , and also functions as part of a conversion portion of the bus slot conversion module  400 , i.e., it provides electrical interconnects to couple pins of the first peripheral slot  412  and the bus slot connector  410 . In several embodiments, for example, interconnects on the first PCB board  408  couple the first peripheral slot  412 , e.g., a single connector attachment (SCA) slot, with appropriate pins of the bus slot connector  410 , e.g., a compact PCI connector. One of ordinary skill in the art is able to connect corresponding pins of a single connector attachment (SCA) slot, an ordinary SCSI slot, or IDE slot with a compact PCI connector using PCB board interconnects; thus further detail of connections between the first peripheral slot  412  and the bus slot connector  410  are not provided.  
     [0064] In practice, a first peripheral, e.g., a floppy drive, disk drive, compact disk drive, or digital video disk (DVD) drive, is coupled with the first peripheral slot  412 , and hence, coupled with the first the bus slot connector  410 . Thus, when the bus slot conversion module  400  is inserted into an available chassis slot, e.g., available chassis slot  206 , and the bus slot connector  410  is coupled with a bus slot, e.g., bus slot  210 , on a backplane, e.g., backplane  208 , the first peripheral is coupled with a backplane bus, e.g., backplane bus  104 , and thus, to other components coupled with the backplane bus.  
     [0065] Referring next to FIG. 6, shown is a view taken along line B-B in FIG. 4B illustrating features of the second PCB board  416 . Shown is the second PCB board  416 , a transverse coupling  602 , a rear edge  604  of the second PCB board  416 , a second peripheral slot  414 , a first peripheral portion  608 , and a second peripheral portion  610 .  
     [0066] The second PCB board  416  is shown generally sectioned into the first peripheral portion  608  and the second peripheral portion  610 . The second peripheral slot  414  is shown coupled with the second PCB board  416  in the second peripheral portion  610  near the rear edge  604  of the second PCB board  416 . The transverse coupling  602  is shown coupled to the second PCB board  416  in between the first peripheral portion  608  and the second peripheral portion  610 .  
     [0067] The second PCB board  416  supports the second peripheral slot  414  and also functions as part of a conversion portion of the canister, i.e., it provides electrical interconnects to couple pins of the second peripheral slot  414  and the transverse coupling  602 . In several embodiments, for example, interconnects on the second PCB board  416  couple the second peripheral slot  414 , e.g., a single connector attachment (SCA) connector, with pins of the transverse coupling  602 . The transverse coupling  602  is a collection of leads that electrically couple the first and second PCB boards  408 ,  416 . Specifically, the transverse coupling  602  electrically connects with interconnects of the first PCB board  408  that couple with the bus slot connector  410 .  
     [0068] One of ordinary skill in the art is able to connect corresponding pins of a single connector attachment SCA connector, an ordinary SCSI connector, or IDE connector with pins of the transverse coupling  602 , and couple the pins of the transverse coupling  602  to appropriate interconnects on the first PCB board  408  that connect with the bus slot connector  410 ; thus further detail of connections between the second peripheral slot  414  and the bus slot connector  410  are not provided.  
     [0069] In practice, a second peripheral, e.g., a floppy drive, disk drive, compact disk drive, or digital video disk (DVD) drive, is coupled with the second peripheral slot  414 , and hence, coupled with the bus slot connector  410 . Thus, when the bus slot conversion module  400  is inserted into an available chassis slot, and the bus slot connector  410  is coupled with a bus slot, e.g., bus slot  210 , on a backplane, e.g., backplane  208 , the second peripheral is coupled with the backplane bus, e.g., backplane bus  104 , and thus, to other components coupled with the back plane bus.  
     [0070] Referring next to FIG. 7, shown is a perspective view of the bus slot conversion module of FIG. 4B with the second PCB board  416  removed. Shown are the front panel  402 , an upper frame bracket  702  (also referred to as a first frame bracket  702 ), a lower frame bracket  704  (also referred to as a lower frame bracket  704 ), a first peripheral  706 , the first peripheral slot  412 , a second peripheral  708 , a second peripheral slot connector  710 , and the bus slot connector  410 .  
     [0071] The front panel  402  is coupled with the upper frame bracket  702  and the first peripheral  706  is detachably coupled with the upper frame bracket  702 . The first peripheral  706  is coupled with the first peripheral slot  412  and the first peripheral slot  412  is coupled with the first PCB board  408 . The second peripheral  708  is detachably coupled with the lower frame bracket  704  and the second peripheral slot connector  710  is coupled with the second peripheral  708 . Also coupled with the first PCB board  408  is the bus slot connector  410 .  
     [0072] The upper frame bracket  702  functions as part of a canister, e.g., canister  114 , to support the first PCB board  408 , to guide the first peripheral  706  into the bus slot conversion module  400  when the first peripheral  706  is inserted in the bus slot conversion module  700  and to support the first peripheral  706  while the first peripheral  706  is in the bus slot conversion module  400 . In FIG. 7, the upper frame bracket  702  is partially obstructed from view by the first peripheral  706 .  
     [0073] The lower frame bracket  704  also functions as part of a canister, e.g., canister  114 , to provide support for the second peripheral  708  while the second peripheral  708  is in the bus slot conversion module  700 , and to couple with, and help support, the second PCB board  416 .  
     [0074] In practice, the first peripheral  706  is inserted into the bus slot conversion module through the front panel  402  along the upper frame bracket  702  until a first peripheral slot connector (not shown) of the first peripheral  706  couples with the first peripheral slot  412 . Similarly, the second peripheral  708  is inserted into the bus slot conversion module  700  through the front panel  402  along the lower frame bracket  704  until the second peripheral slot connector  710  couples with the second peripheral slot  414 .  
     [0075] Referring next to FIG. 8, shown is a perspective view of the bus slot conversion module  400  of FIG. 4A with the first PCB board  408  removed. Shown is the upper frame bracket  702 , the front panel  402 , the first and second peripheral face plates  404 ,  406 , and the second peripheral  708 .  
     [0076] A face of the upper frame bracket  702  normally coupled with the first PCB board  408  is shown exposed and coupled with the front panel  402 . The first peripheral face plate  404  and the second peripheral face plate  406  are shown in a tandem relation to each other and are both coupled with the front panel  402 . The second peripheral  708  is coupled with the second peripheral face plate  406  and is shown extending through the front panel  402  to a rear portion of the bus slot conversion module  800 .  
     [0077] Referring next to FIG. 9, shown is a view of the bus slot conversion module  700  of FIG. 7 with the first peripheral  706  removed. Shown are the front panel  402 , the upper frame bracket  702 , the first peripheral slot  412 , the lower frame bracket  704 , the second peripheral  708 , the second peripheral slot connector  710 , the bus slot connector  410 , and the front panel  402 . Also shown is a first panel slot  900 .  
     [0078] The components shown of the bus slot conversion module  900  of FIG. 9 are shown interconnected as in FIG. 7 except that the first peripheral  706  is shown removed; thus exposing the first panel slot  900  in the front panel  402  and an inside portion of the upper frame bracket  702 .  
     [0079] In practice, the first panel slot  902  provides an opening through which the first peripheral  706  is inserted and guided by the upper frame bracket  702  until a first peripheral slot connector of the first peripheral  706  couples with the first peripheral slot  412 . Thus, the first panel slot  902 , the upper frame bracket  702  and the first peripheral slot  412  form a first peripheral dock, e.g., the first peripheral dock  214 .  
     [0080] Referring next to FIG. 10, shown is a view of the bus slot conversion module  900  of FIG. 9 with the lower frame bracket  704  removed. Shown are the front panel  402 , the upper frame bracket  702 , the first peripheral slot  412 , the second peripheral  708 , the second peripheral slot connector  710 , the bus slot connector  410 , the front panel  402 , and the first panel slot  902 .  
     [0081] The components of the bus slot conversion module  1000  shown in FIG. 10 are shown interconnected as the bus slot conversion module  900  of FIG. 9 except that the lower frame bracket  704  is removed; thus exposing the second peripheral  708  to view. As shown, the second peripheral  708  is completely inserted within the bus slot conversion module  1000  and extends almost a full length of the bus slot conversion module  1000 .  
     [0082] Referring next to FIG. 11, shown is a view of the bus slot conversion module  900  of FIG. 9 with the second peripheral  708  removed. Shown are the front panel  402 , the upper frame bracket  702 , the first peripheral slot  412 , the bus slot connector  410 , the front panel  402 , the first panel slot  902 , the lower frame bracket  704 , and a second panel slot  1102 .  
     [0083] The components shown in FIG. 11 are shown interconnected as in FIG. 9 except that the second peripheral  708  is removed; thus exposing the second panel slot  1102  to view in the front panel  402  through the lower frame bracket  704 .  
     [0084] In practice, the second panel slot  1102  provides an opening through which the second peripheral  708  is inserted and guided by the lower frame bracket  704  until the second peripheral slot connector  710  couples with the second peripheral slot  414 . Thus, the second panel slot  1102 , the lower frame bracket  704  and the second peripheral slot  414  form a second peripheral dock, e.g., the second peripheral dock  215 .  
     [0085] Referring next to FIG. 12, shown is a rear view of the bus slot conversion module of FIG. 4A. Shown are the first peripheral  706 , the first peripheral slot  412 , the second peripheral  708 , the second peripheral slot  414 , and the bus slot connector  410 .  
     [0086] The first peripheral  706  is shown coupled with the first peripheral slot  412  at a rear end of the bus slot conversion module  400  (an end opposite the front panel  402 ), and the second peripheral  708  is shown coupled with the second peripheral slot  414  at the rear end of the bus slot conversion module  400 . Also shown at the rear end of the bus slot conversion module is the bus slot connector  410 .  
     [0087] Referring next to FIG. 13, shown is another rear view of the bus slot conversion module of FIG. 4A showing a relationship between the first and second peripherals  706 ,  708  and the first and second PCB boards  408 ,  416 .  
     [0088] Shown are the first PCB board  408 , the first peripheral  706 , the second PCB board  416  and the second peripheral  708 . The first and second PCB boards  408 ,  416  are each shown closely sandwiched between the first and second PCB boards  408 ,  416 , however, the upper and lower frames  702 ,  704  separate the first and second peripherals  706 ,  708  respectively from the first and second PCB boards  408 ,  416 .  
     [0089] Referring next to FIG. 14, shown is an end view of the first and second PCB boards  408 ,  416  and interconnections between them. Shown are the first PCB board  408 , the first peripheral slot  412 , the transverse coupling  602 , the second PCB board  416 , the second peripheral slot  414  and the bus slot connector  410 .  
     [0090] The first peripheral slot  412  and the bust slot connector  410  are shown coupled with the first PCB board  408 , and the second peripheral slot  414  is coupled with the second PCB board  416 . The first and second PCB boards  408 ,  416  are shown coupled by the transverse coupling  602 .  
     [0091] As discussed previously with reference to FIG. 6, the transverse coupling is a collection of leads that electrically couple the first and second PCB boards  408 ,  416 . Specifically, interconnects on the second PCB board  416  (e.g., traces) that connect with the second peripheral slot  414  are coupled by the transverse coupling  602  to interconnects on the first PCB board  408  that connect with the bus slot connector  410 .  
     [0092] In practice, the first and second PCB boards  408 ,  416  and the transverse coupling  602  function to convert the bus slot connector  410  to the first and second peripheral slots  412 ,  414 . Thus, according to several embodiments, the first and second PCB boards  408 ,  416  and the transverse coupling  602  are part of a conversion portion of a canister, e.g., canister  212 .  
     [0093] Referring next to FIG. 15A, shown is a rear transition module  1500  in accordance with one embodiment of the rear transition module of FIG. 2. Shown are the rear transition module  1500 , a first, second, third and forth horizontal peripheral slots,  1502 ,  1504 ,  1506 ,  1508  a rear PCB board  1510 , a first and second vertical peripheral slots,  1512 ,  1514  handles  1516 , a rear bus slot connector  1518 , and a rear transition panel  1520  The rear transition panel  1520  is coupled with the rear PCB board  1510  and the first, second, third and forth horizontal peripheral slots  1502 ,  1504 ,  1506 ,  1508 . Coupled with the rear PCB board  1510  are the first and second vertical peripheral slots  1512 ,  1514  and the rear bus slot connector  1518 .  
     [0094] The rear bus slot connector  1518  in several embodiments is a compact PCI connector that is designed to couple with a bus slot of a backplane, e.g., the rear bus slot  210  of the backplane  208 .  
     [0095] In several embodiments, the rear PCB board  1510  provides electrical interconnects between the first and second vertical peripheral slots  1512 ,  1514  and the first and second horizontal peripheral slots  1502 ,  1504 , but does not electrically interconnect with the third and forth horizontal peripheral slots  1506 ,  1508 . In these embodiments, cables are used to couple the first vertical peripheral slot  1512  with the third horizontal peripheral slot  1506  and the second vertical peripheral slot  1514  with the forth horizontal peripheral slot  1508 .  
     [0096] In operation, as discussed with reference to FIG. 2, the rear transition module  1500  is inserted into a rear portion of a chassis, e.g., the chassis  204 , and coupled with a rear side of an available bus slot, e.g., bus slot  210 , on a backplane, e.g., backplane  208 . Once in the chassis, the rear transition module  1500 , according to several embodiments, provides peripheral slots at a rear of the backplane. In the present embodiment, there are four horizontal peripheral slots, i.e., the first, second, third and forth horizontal peripheral slots  1502 ,  1504 ,  1506 ,  1508  that are accessible from a rear of a chassis.  
     [0097] Referring next to FIG. 15B, shown is an inside and perspective view of the rear transition module of FIG. 15A. Shown are the rear transition module  1500 , the rear transition panel  1520 , the first, second, third and forth horizontal peripheral slots  1502 ,  1504 ,  1506 ,  1508 , the rear PCB board  1510 , the first and second vertical peripheral slots  1512 ,  1514 , the handles  1516 , and the rear bus slot connector  1518 .  
     [0098] The described components of FIG. 15B are coupled in the same manner, and interoperate in the same manner as the corresponding components of FIG. 15A. As shown in FIG. 15B, the first and second horizontal peripheral slots  1512 ,  1514  are coupled from an inside of the rear transition panel  1520  to the rear PCB board  1510 ; thus interconnects from the rear bus slot connector  1518  to the first and second horizontal peripheral slots  1502 ,  1504  are easily made with the rear PCB board  1510 .  
     [0099] While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.