The RP contains the central processing unit (CPU), the system software, and most of the memory components that are used in Cisco 7000 series routers. The system software resides on eight electronically erasable read-only memory (EPROM) components, which are also called system ROMs or boot ROMs. Although these ROMs are replaceable, most system software upgrades are distributed on floppy disk. This enables you to download and boot from upgraded software images remotely, without having to remove the RP and replace the ROMs.