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Cisco 7204 Installation and Configuration Guide
OL-5101-02
Chapter1 Product Overview Physical Description
Input/Output Controller
The Input/Output controller shares the system memory functions and the environmental monitoring
functions for the Cisco 7204 router with the network processing engine.
Note Detailed instructions for removing and replacing the I/O controller are contained in the configuration
note Input/Output Controller Replacement Instructions. The configuration note is also available on
Cisco.com.
The I/O controller consists of the following components:
•Dual EIA/TIA-232 channels for local console and auxiliary ports. The console port has full DCE
functionality and a DB-25 port. The auxiliary port has full DTE functionality and a DB-25 plug.
•An optional Fast Ethernet port, equipped with either a singl e M II po rt ( see Figure 1-7) o r an M II
port and an RJ-45 port (see Figure 1-8), that is configurable f or use a t 100 megab its pe r secon d
(Mbps) full-duplex or half-duplex (half-duplex is the default). The I/O controller without the Fast
Ethernet port is shown in Figure 1-9.
Note When you use the I/O controller that is equipped with an MII po rt and an RJ-45 port, only one port can
be configured for use at a time. Although still supported by Cisco Systems, the I/O controller equipped
with the single MII port was discontinued as an orderable pr oduct in M ay 1 998 .
•NVRAM for storing the system configuration and environmental monitoring logs. NVRAM uses
lithium batteries to maintain its contents when disconnected from power.
•Flash memory SIMM for storing the boot helper image.
•Two PCMCIA slots for Flash Disks or Flash memory cards, which contain the default Cisco IOS
software image.
•Boot ROM for storing sufficient code for booting the Cisco IOS software.
•Two environmental sensors for monitoring the cooling air as it enters and leaves the Cisco 7204
chassis.