@Xi Computer Corporation MTower, User Manual

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Appendix D, Glossary
Page 102
SIMM
An acronym for Single In-line Memory Module, a small
printed circuit board holds a group of memory chips.
SIMMs hold up to nine RAM chips. The computer bus from
a SIMM to the actual memory chips is 32 bits wide,
compared to the 64-bit-wide path by DIMMs. Because
Pentium processors require a 64-bit path to memory, you
need to install two SIMMs a time, as opposed to installing
one DIMM at a time.
Sound card
An expansion card that allows a computer to output sounds.
Sound cards are required for nearly all CD-ROMs and
DVD-ROMs. Sound is output through speakers connected
to the sound card. Similarly, sound can be input into a sound
card using a microphone and then stored on the computer’s
hard drive.
Spike An intense increase/decrease in voltage. Spikes are more
extreme than a surge and of shorter duration. Spikes can
scramble a computer's memory, causing odd things to occur.
In extreme cases, spikes can actually melt wiring.
Surge A transient increase of power for more than a fraction of a
second and less than 2.5 seconds. Surges cause a power
supply to generate heat. Heat is the major cause of
equipment failure.
Surge protector A device that protects attached devices against spikes.
Surge suppressor A device designed to protect devices against surges. Surge
suppressors are also referred to as “line conditioners” or just
“conditioners.”
System unit The “heart” of the computer. All external devices, such as
monitor, keyboard, and mouse connect to the back of the
system unit. The main board (or motherboard), video
adapter, floppy disk/hard disk/CD-ROM controller and
drives, power supply, and any expansion boards are all
installed inside the system unit.