All about memory

OBJECTIVE To enable the builder to recognize and install memory sticks on the motherboard

RAM (or Random Access Memory) is an important part of the computer system which is used by actively running programs to perform necessary tasks while the computer is on. It is composed of integrated circuit memory chips that allow information to be stored or accessed in any order and all storage locations are equally accessible. The information on RAM can be tossed out to make more space, as opposed to the Hard Disk Drive where the computer stores information for the long haul.

Memory sticks, or RAM, come in 2 types, DIMM and SIMM

DIMM (Dual In-Line Memory Module)

• DIMMs are usually 5.25" long and plug into slots that have plastics clips at the end that open and close to hold them in. There is also a type of DDR that is only 2.5-2.75" long known as SODimm that is used in laptops and small computer systems

SIMM (Single In-Line Memory Module)

• SIMM is the oldest form of memory that we still see and is shorter than the currently-used types - generally 4.25" long or 3.5" long. Its slots on the motherboard have metal clamps at the end to hold the stick in place.

Exercise: Look at the example memory sticks and match them up with the following pictures and descriptions

DDR

A stick of DDR has a single notch in it near the center of the stick.
Un módulo de DDR tiene una muesca en en el centro del módulo.

RAMBUS

A stick of RAMBUS has two notches in it at the center of the stick.
Un módulo de RAMBUS tiene dos muescas en en el centro del palo.'

SDRAM

A stick of SDRAM has two notches in it, one near the center of the stick, and one closer to the side.
Un módulo de SDRAM tiene dos muescas, una cerca del centro del módulo, y otra cerca a un extremo del módulo.

72 pin SIMMs are 4.25 inches long. The holes and notches need to match exactly since there are other objects that look like 72-pin SIMM but aren't, so see points A (side holes), B (center notch) and C (side notch) in the picture.

30 Pin SIMM