like you have to force a module into place, you are probably trying to use the
wrong type of module.Some techie-types get all exorcised over whether the memory modules you
purchase have connector pins that are plated with gold, tin, or aluminum.
Their concern has a kernel of truth: Gold is the most stable and least likely to
corrode or otherwise cause problems with the electrical connection between
memory and the motherboard. But tin (and less commonly, aluminum) also
works for many years without problem. In theory, the worst case is a mix-
and-match of gold-plated connectors in the slot and tin on the module or
the other way around; over time, the lesser metal (tin) may pass some of its
molecules over to the gold, causing oxidation. To avoid the problem, use
gold-plated modules with gold-plated connectors, and tin plate with tin plate.
To my way of thinking, this is a problem that — if it happens at all — takes
many years to occur, and laptops are much more likely to die of other causes
or just become outmoded before this becomes an issue.MicroDIMM
The smallest of notebook computers may use a tiny memory module called
a MicroDIMM, which is 3.92×2.54cm, or about 1.5×1 inches. Like SODIMMs,
MicroDIMMs are available with either 144 or 172 pins. The pins on each side
of the MicroDIMM are not electrically connected, permitting two independent
data paths between the module and system. The modules do not have notches
along the pin end, but they do have a top and bottom. On most machines the
module is installed so that the memory chip labeling faces toward you as
installed in the slot. MicroDIMMs provide a 64-bit data path, and in modern
machines they can be installed one at a time — they do not need to be
installed in pairs.Figure 6-2:
A 72-pin
SODIMM is
top left, a
144-pin
SODIMM
is top
right, and
a 144-pin
MicroDIMM
is on the
bottom.
Chapter 6: Brain Matters: Memory, Microprocessors, and BIOS 93