Computer Hardware Basics PDF

Notes - Computer Hardware Basics
The Computer
A computer is made up of many parts:
1. Input/Output (I/O) devices – These allow you to send information to the
computer or get information from the computer.
2. Central Processing Unit – CPU or Processor for short. The brain of a
computer. Approximately 1.5 in X 1.5 in. Does all the computation/work for
the computer.
3. Memory – Although memory is technically any form of electronic storage, it
is used most often to identify fast, temporary forms of storage. Accessing the
hard drive for information takes time. When the information is kept in
memory, the CPU can access it much more quickly.

a. Random Access Memory – RAM. Where information is stored
temporarily when a program is run. Information is automatically
pulled into memory, we cannot control this. RAM is cleared
automatically when the computer is shutdown or rebooted. RAM is
volatile (non-permanent).
b. Read Only Memory – ROM. More permanent than RAM. Data
stored in these chips is nonvolatile -- it is not lost when power is
removed. Data stored in these chips is either unchangeable or requires
a special operation to change. The BIOS is stored in the CMOS, read-
only memory.
c. Hard Drive – Where you store information permanently most
frequently. This is also nonvolatile.
4. Motherboard – A circuit board that allows the CPU to interact with other
parts of the computer.

5. Ports – Means of connecting peripheral devices to your computer.
a. Serial Port – Often used to connect a older mice, older external
modems, older digital cameras, etc to the computer. The serial port
has been replaced by USB in most cases. 9-pin connector. Small and
short, often gray in color. Transmits data at 19 Kb/s.
b. Monitor Ports – Used to connect a monitor to the computer.
PCs usually use a VGA (Video Graphics Array) analog connector (also
known as a D-Sub connector) that has 15 pins in three rows. Typically
blue in color.
Because a VGA (analog) connector does not support the use of digital
monitors, the Digital Video Interface (DVI) standard was developed.
LCD monitors work in a digital mode and support the DVI format. At one
time, a digital signal offered better image quality compared to analog
technology. However, analog signal processing technology has improved
over the years and the difference in quality is now minimal.
c. Parallel Port – Most often used to connect a printer to the computer.
25-pin connector. Long and skinny, often pink in color. Transmits
data at 50-100 Kb/s.