User Guide

ASUS A7A133 User’s Manual 23
3. HARDWARE SETUP
3.5.2 Memory Installation
WARNING! Make sure that you unplug your power supply when adding or
removing memory modules or other system components. Failure to do so may
cause severe damage to both your motherboard and expansion cards (see 3.3
Hardware Setup Procedure for more information).
Insert the module(s) as shown. Because the number of pins are different on either
side of the breaks, the module will only fit in the orientation shown. SDRAM DIMMs
have different pin contacts on each side and therefore have a higher pin density.
(DRAM SIMM modules have the same pin contacts on both sides.)
The notches on the DIMM will shift between left, center, or right to identify the type
and also to prevent the wrong type from being inserted into the DIMM slot on the
motherboard. You must tell your retailer the correct DIMM type before purchasing.
This motherboard supports four clock signals per DIMM.
The DIMMs must be 3.3Volt unbuffered SDRAMs. To determine the DIMM type,
check the notches on the DIMMs (see figure below).
168-Pin DIMM Notch Key Definitions (3.3V)
DRAM Key Position
Voltage Key Position
Unbuffered
RFU
Buffered
Reserved
3.3V
5.0V
Memory Installation
3. H/W SETUP
A7A133
A7A133 168-Pin DIMM Sockets
Lock
20 Pins
60 Pins
88 Pins