A computer or an electronic system usually requires storage devices for storing the data and information that it processes and needs to support its operations. These storage devices may be internally mounted within the housing or external to the computer or electronic system.
As computer and electronic system components become smaller, the enclosures that house these systems also become smaller. The advantage of reducing the size of such systems is for ease of transportation, installation, reduced total power consumption, and reduced office space consumption.
Any given computer system is designed to fit any variety of customer applications. Some of these applications require relatively little disk storage and others a great amount. The object of any computer design is to fill as many needs as reasonably possible without making the system excessively large or expensive. For many applications, this results in the need for varying amounts of external storage. Directly connected external storage devices are usually located adjacent to the computer or electronic system, but even short cables negatively impact the reliability and performance of such external storage devices.
To properly protect the environment from contamination from noise contained within the cables connected to the external storage devices, and to protect that data within the cable from possible corruption from outside noise, the cable run must be shielded in some way. However, such shielding significantly contributes to the difficulty in designing a reliable and cost efficient electrical data connection.
One of the advantages, however, in using external storage devices is that there is no practical limit in the number of storage devices that may be connected to the computer or electronic system. Therefore, as long as there are unused input/output ("I/O") ports, storage devices may be added to increase the system's storage capacity.
Computer housings have shielding associated with them. Therefore, when storage devices are internally mounted, interference and noise internal to the housing that they generate will not radiate to the external environment. However, there are a number of problems associated with internally mounting storage devices. A few of these problems are the limitation on the number of storage devices that can be mounted to a storage assembly because of the space constraints, the existence of lengthy electrical stubs associated with a common bus, difficulty in providing clean power to the storage devices, the ability to easily expand a system's storage capacity, the difficulty in cooling the storage devices, and the ability to isolate the storage devices from external sources of physical shock and vibration.
Conventional storage assemblies generally do not employ methods which permit more than a few storage devices to be internally mounted on a storage assembly. For example, some conventional storage assemblies only permit one storage device to be connected to them. In many cases it is desirable to provide a storage assembly that accommodates the connection of a number of storage devices.
Internally mounted storage devices, which are conventionally connected to a computer or an electronic system, often have lengthy stubs associated with the connection of storage devices to a common bus. Because of the transmission line effects, the introduction of lengthy stubs limit the maximum configuration and reliability of the common bus that connects to all of the storage devices. It is desirable to have a storage assembly that is not plagued with the stub problem.
Modern storage devices require high current and high speed changes in current. These operational power needs for internally mounted storage devices are not satisfied with conventional techniques for providing power because such operational power needs of modern storage devices exceed the capability of conventional power distribution methods. Thus, it is desirable to have a storage assembly that can satisfy the required operational power needs of modern storage devices.
There also has been difficulty is expanding the storage capacity of computer or electronic systems beyond that which is provided by the internally mounted storage devices. It fact, many systems with internally mounted storage devices are not expandable at all.
The expansion problem also is manifest in individual storage assemblies being part of a larger storage assembly with all of the individual assemblies being connected by a common bus. Such a configuration cannot be readily expanded because of the difficulty in making bus and other connections without adversely affecting the system.
The present invention provides an storage assembly that overcomes these and other problems as will be set forth in detail in the remainder of the specification and shown in the drawings.