Installation guide

Upgrading Memory in Cisco 4000 Series Routers 21
SIMM Orientation
Figure 15 Cisco 4700-M and Newer Cisco 4500-M Memory Locations
SIMM Orientation
SIMMs are manufactured with a polarization notch to ensure proper orientation, and alignment holes
that fit over guide posts to ensure proper positioning.
Figure 16 shows the polarization notch and alignment holes on a typical SIMM. SIMMs vary in their
physical dimensions and in the number, size, and location of components on the surface of the card,
depending on the router they are installed in, the type of memory, and the SIMM manufacturer.
Figure 16 Typical Cisco 4000 Series SIMM
Caution
To avoid damaging ESD-sensitive components, observe all ESD precautions when
handling SIMMs. To avoid damaging the motherboard or the SIMM, avoid excessive force when you
remove or replace SIMMs.
Main memory SIMM sockets
with correct SIMM orientation
Front of chassis
Motherboard
Shared-memory
SIMM and socket
H6665
System Flash memory 1
J5
J1
J6
System Flash memory 0
RxBoot Flash memory
Jumper in place enables
writing to Flash memory
Jump pins
1 and 2
Jump pins 1 and 2
ROM monitor
U78
NVRAM
Alignment holes
Connector edge
Polarization notch
H1154a