Computer memory chips are actually small circuit boards that contain a group of memory chips available in 32-bit or 64-bit bus widths called a SIMM or Single In-Line Memory Module containing megabyte (MB) or gigabyte (GB) chips.
To boost available memory, you've got to know the exact type of memory chip configuration and the number and type of pins each SIMM chip has.
With older models, the SIMM chips are easily accessed.
All you have to do is snap open the retaining clips, pull out a SIMM and replace it with another.
Each computer is different, so yours will have a particular SIMM designed for it that contains the exact number of pins fitting eaxctly into a slot on your computer motherboard or the engine of the computer.