Memory subsystem 622 used in the storage subsystem 610 can include a number of memories including a main random access memory (RAM) 632 for storage of instructions and data during program execution and a read only memory (ROM) 634 in which fixed instructions are stored. A file storage subsystem 636 can provide persistent storage for program and data files, and can include a hard disk drive, a floppy disk drive along with associated removable media, a CD-ROM drive, an optical drive, or removable media cartridges. The modules implementing the functionality of certain implementations can be stored by file storage subsystem 636 in the storage subsystem 610, or in other machines accessible by the processor.

Bus subsystem 655 provides a mechanism for letting the various components and subsystems of computer system 600 communicate with each other as intended. Although bus subsystem 655 is shown schematically as a single bus, alternative implementations of the bus subsystem can use multiple busses.

Computer system 600 itself can be of varying types including a personal computer, a portable computer, a workstation, a computer terminal, a network computer, a television, a mainframe, a server farm, a widely-distributed set of loosely networked computers, or any other data processing system or user device. Due to the ever-changing nature of computers and networks, the description of computer system 600 depicted in FIG. 6 is intended only as a specific example for purposes of illustrating the preferred embodiments of the present invention. Many other configurations of computer system 600 are possible having more or less components than the computer system depicted in FIG. 6.

Particular Implementations