Installation guide

6 Upgrading Memory in Cisco 4000 Series Routers
Memory Systems
Figure 1 Cisco 4000 Series EPROM-Based and Flash-Based Memory Systems
The following sections describe memory systems in each router in the Cisco 4000 series.
Cisco 4000
The Cisco 4000 router contains the following memory systems:
• Four SIMM sockets for main memory (4 x 1 MB or 4 x 4 MB).
• Four SIMM sockets for shared memory (4 x 1 MB).
• One socket for a memory daughter card containing either Flash EPROM or Flash SIMMs. The
original daughter cards support either 2 or 4 MB of EPROM. Replacement daughter cards
support 8 or 16 MB of Flash SIMMs, using either two 4-MB SIMMs or two 8-MB SIMMs.
Cisco 4000-M
The Cisco 4000-M router contains the following memory systems:
• One SIMM socket for main memory (8, 16, or 32 MB).
• One SIMM socket for shared memory (4 or 16 MB).
• Two SIMM sockets for Flash memory. One or both may be filled. When both are filled, equal
memory sizes are required (4 MB, or 4 and 4 MB).
Cisco 4500
The Cisco 4500 router contains the following memory systems:
• Two SIMM sockets for main memory. Both must be filled, and they must contain equal memory
sizes (4 and 4 MB, or 16 and 16 MB).
• One SIMM socket for shared memory (4 or 16 MB).
• Two SIMM sockets for system Flash memory, plus one for boot helper Flash memory. One or
both system Flash-memory sockets may be filled. When both are filled, equal memory sizes are
required (4 MB, or 4 and 4 MB).
Cisco 4000 and Cisco 4000-M
EPROM-based Flash-memory based
Boot helper
(xboot)
ROM monitor
Cisco IOS
Cisco 4500, Cisco 4500-M, Cisco 4700, and Cisco 4700-M
EPROM-based Flash-memory based
ROM monitor
Boot helper
(xboot)
H3537
Cisco IOS