Datasheet

18 Chapter 1
N
Personal Computer System Components
FIGURE 1.10 A CNR slot
FIGURE 1.11 Different memory module form factors
30-pin SIMM (3.5  .75˝ )
144-pin SODIMM (2.625  1˝ ) 72-pin SODIMM (2.375  1˝ )
72-pin SIMM (4.25  1˝ )
168-pin DIMM (5.375  1˝ )
Memory slots are easy to identify on a motherboard. DIMM slots are usually black and
placed very close together. DIMM slots with pair-by-pair color coding can be observed these
days, however. Generally, the pairs of slots must be filled together for best performance or to
work at all, in some cases. Consult the motherboard’s documentation to determine the specific
modules allowed as well as their required orientation. The number of memory slots varies
from motherboard to motherboard, but the structure of the different slots is similar. Metal
pins in the bottom make contact with the metallic pins on each memory module. Small metal
or plastic tabs on each side of the slot keep the memory module securely in its slot.
86498book.indb 18 7/22/09 5:37:27 AM