Apple MacBook (13-inch, Late 2009) - Manual (Page 46)

46 Chapter 3 Boost Your MacBook
Installing Additional Memory
Your computer has two memory slots that you access by removing the bottom case.
Your MacBook comes with a minimum of 2 gigabytes (GB) of 1066 MHz Double Data
Rate (DDR3) Synchronous Dynamic Random-Access Memory (SDRAM) installed. Both
memory slots can accept an SDRAM module that meets the following specifications:
 Double Data Rate Small Outline Dual Inline Memory Module (DDR3) format
 30 mm (1.18 inches)
 204-pin
 1 GB or 2 GB
 PC3-8500 DDR3 SO-DIMM 1066 MHz Type RAM
You can add two 2 GB memory modules for a maximum of 4 GB of memory. For
best performance, fill both memory slots and install an identical memory module
in each slot.
To install memory in your MacBook:
1 Follow steps 1 through 3 beginning on page 37.
Important: When you remove the bottom case, you expose sensitive internal
components. Avoid touching anything other than the memory assembly when you
remove or add memory.