Lenovo ThinkCentre A61 - Manual (Page 20)

v Use 1.8 V, 240-pin, double data rate 2 synchronous dynamic random access
memory (DDR2 SDRAM).
v Use 256 MB, 512 MB, 1 GB, or 2 GB memory modules in any combination up to
a maximum of 4.0 GB.
Note: Only DDR2 SDRAM DIMMs can be used.
To install a memory module:
1. Remove the computer cover. See “Removing the cover” on page 9.
2. You might have to remove the drive bay assembly to access the memory
connectors. See “Accessing system board components and drives” on page 10.
3. Remove any parts that might prevent access to the memory connectors.
4. Locate the memory connectors. See Figure 4 on page 7.
12 Hardware Installation and Replacement Guide