4. The processor
• Integral to all computers is
the processor, or central
processing unit ( CPU). It is
also often referred to as
microprocessor.
Its role is to process the
data entered, following
the directions of the
software, into the
information required.
8. Control unit
• a control unit (CU) is a
central (or sometimes
distributed but clearly
distinguishable) part of a
mechanism that controls
its operation.
10. Memory
• Within the memory is
all data needed in the
phases of the
information processing.
These include the
inputted data, the
operating system and
the application
program.
11. Two distinct types
• PRIMARY ( THE INERNAL
MEMORY IN THE CPU)
• SECONDARY ( EXTERNAL
MEMORY OF A MORE
PERMANENT TYPE)
13. Two types of memory
Read only memory
(ROM)
Is a permanent internal
silicon chip that is inserted
before contraction. The
programs contained in this
memory store can be read
and used but cannot be
changed altered or erase.
15. Random access memory
(RAM)
• Is the temporary memory
that is available to the
operator to us and
manipulate . It stores the
operating system and
application software while
the computer is in use. The
contents of RAM are not
permanent and are erased
when the computer’s power
is switched off .
17. BUS
• within the computer. Data is
transferred along data lines
called buses. The bus is a
series of circuits connecting
the processor and other parts
of the motherboard.
• Its purpose is to transfer data
within the computer . Buses do
not stores and manipulate
data.
19. PORTS
• Serial ports and
parallel ports are found
at the back of the most
PS’s. they are the
interface between
peripheral devices,
such as printers and
modems in the
computers.
23. Mouse, Trackball, Touch pad and Track
point
• The mouse is almost as
common as a keyboard, and is
now generally a standard
peripheral with most system, a
mouse is hand operated and
allows the user to move the
cursor around the screen.
• Trackballs look similar in the
upside down mouse placed in
the middle of the keyboard.
24. • Touch pad allows you to
simply move your finger
over its surface to move
the pointer.
• A track point has all the
features of a mouse in a
one small pointer that
protrudes from the middle
of the laptop keyboard.
26. BARCODE READER
• A barcode is a block of
vertical black lines and
white spaces, representing
an alphanumeric code that
identifies the item. The
barcode reader needs these
codes and produces a series
of pulses that corresponds
to the barcode.
27. Types of a barcode
• Flat barcode- are commonly
used in super markets, as
they are more efficient.
• Hand held- this are commonly
found in departments and
hardware stores, where
because their products are
varying in size and shapes.
28. • Pen barcode- are generally
found in libraries or
barrowing outlets such as
video shops. Pen readers
usually record the barcode
of the barrower( normally
on a card) and the barcode
of the item being
barrowed.
30. SWIPE CARD READER
• Swipe card readers
electronically read the
magnetic strip on the
back of the card. The
information on the strip
is then matched with the
personal identification
number entered by the
cards owner.
32. SCANNER
• Flat-Bed. Drum and hand
held scanners are input
devices that can take text
and image and turn them
into digital data. The
material can be in a form of
text, drawings, or
photographs. With the use
of software, image can be
manipulated and text
edited.
36. TOUCH SCREENS
• Another input device that has
become popular in
environments used by non
experts is the touch screen.
This allows the user too select
he desired option by the ouch
of a finger on the screen.
