Information Technology Reference
In-Depth Information
Bench Repair Technician
A bench repair technician is like a mechanic for comput-
ers. As the word
bench
implies, this technician works
primarily at a workbench in a repair shop, although mobile
repair technician positions are also available. Bench repair
technicians can diagnose system problems with comput-
ers that customers bring in for repairs, including both
hardware problems like defective parts and software prob-
lems like virus infections. This position requires either a
two-year degree in Computer Technology or a professional
certification such as CompTIA's A+ certification. It is a
good job for someone who prefers working mostly with the
computers themselves rather than with their users.
© iStockphoto.com/Andrew_Howe
Understanding CPUs
Every computer has at least one processor, also called a
central process-
ing unit (CPU)
. The CPU contains millions of tiny transistors and
pathways that take in data and instructions, process (calculate) the data
according to the instructions, and output the results of the calculations.
A computer may also have smaller processors used in specific subsystems,
such as a graphics processor.
central processing unit (CPU)
The main
processor in a computer.
Every CPU includes the following components:
◾
The
control unit
manages the flow of data through the CPU. It
directs data to and from the other components within the CPU.
◾
The
arithmetic logic unit (ALU)
component does the actual pro-
cessing. It receives data and instructions and delivers a result. For
example, if it received the numbers 3 and 5, and the instruction
Sum,
it would return 8.
◾
Registers
are holding areas for both data and instructions. There
are many different registers, each with its own special purpose.
For example, there are registers that hold data, registers that hold
instructions, registers that store logical states (yes/no), temporary
values that serve as increment counters, and so on.
Physical Composition of.a CPU
Physically, a CPU is a very small and thin sheet of
semiconductor
material
(usually silicon) with a complex array of tiny transistors and buses stamped
into it with a die. Semiconductor material is used for CPUs because it does
not affect the flow of electricity one way or another: The semiconductor
neither conducts nor impedes the electrical flow. The components inside
the CPU are so small that you need a microscope to see them.
semiconductor
Material that is electricity-neutral,
neither a good conductor nor a flow preventer.
The CPU is fragile, so it is protected by a sturdy ceramic and metal
casing; some models are mounted on miniature square circuit boards.
The underside of this casing contains either tiny pins or tiny metal dots,
