1. Unit 1 : Computing Fundamentals
Lesson Topic
1
• Identifying Computers
• Desktop Computers
• Notebooks or Laptop Computers
• Tablets
• Hand-held or Mobile Computers
Lesson 1 : Computers all around Us
• System unit
• Microprocessor chip
• How memory is measured
• What ROM is
• What RAM is
• How memory works
Lesson 2 : Elements of a Personal Computer
• Storage systems
• Hard disk drives
• Optical drives
• Portable or removable storage devices
Lesson 3: Working with Storage Systems
• Hardware
• Input/output devices
• Input devices
• Output devices
• Using Software
• Software Copyright.
Lesson 4 :Using Input/output Devices
2. • A Computer is a general purpose device that can be programmed to carry out
a set of arithmetic or logical operations. It consists of at least one processing
element, typically a central processing unit (CPU) and some form of memory.
• Integrated in our work, home, and social environments
• Perform a multitude of tasks
• Computers can be:
− Designed specifically as computing devices
− Embedded in products
2
Identifying Computers
Computers all
around Us
3. • Called personal computers
• Sit on, beside, or under desk
• Process data quickly
• Typically used in small businesses, schools, and homes.
• Generally two types
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PC
Mac
Desktop Computers
Computers all
around Us
4. • Advantages
− Portability
− Power consumption considered “greener” alternative
− Can purchase accessories to enhance enjoyment and experience
• Netbook
− Similar to notebook but smaller and less expensive
− Designed to handle wireless communications or access to
Internet only 4
PC Notebook
Mac Notebook
Notebooks or Laptop Computers
Computers all
around Us
5. • Similar to notebook for portability and connection to data
• Screen can swivel or fold over
• Uses touch screen capability for data entry
− With finger, pen device, or built-in keyboard
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Tablets
Computers all
around Us
6. • Often most important and expensive part
• Separate devices inside box perform specialized
functions
• Notebook has same components as desktop
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System Unit
Elements of
a Personal Computer
7. • Microprocessor chip
− Often called “brain” of computer as instructions from
software programs and input received are executed
here
− Referred to as Central Processing Unit (CPU).
− Processes information and instructions at different speeds
− Hertz (Hz) measures speed of internal computer clock in terms of
frequency or number of cycles per second
− Dual and quad core processors contain two or four processor chips
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System Unit - Microprocessor chip
Elements of
a Personal Computer
8. 8
Processor (CPU) MHz or GHz
8088 (XT) 4 to 10 MHz
80286 (286 or AT) 8 to 16 MHz
80386SX/DX (386SX/DX) 16 to 33 MHz
80486 (486) 25 to 100 MHz
Pentium (MMX) 166 to 200 MHz
Pentium PRO 150 to 200 MHz
Pentium II 200 to 400 MHz
Pentium III 500 MHz to 1.2 GHz
Pentium 4 or Pentium M 1.4 to 3.2+ GHz
Pentium 5 5 GHz to 7 GHz
System Unit - Microprocessor chip
Elements of
a Personal Computer
9. • Computers developed using numbering system of 1s and 0s or binary system
• For computer to store information, must have memory chips installed
• All data made up of bytes in combinations calculated by computer
− Every file used in software program has specific file size
− Data file size increases or decreases based on contents stored
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Memory
Elements of
a Personal Computer
10. • Memory measured in bits and bytes
− Bit is smallest unit of data used by computers
− Group of eight bits make one byte
1 Kilobyte = 1,024 Bytes
1 Megabyte = 1,048,576 Bytes
1 Gigabyte = 1,073,741,824 Bytes
1 Terabyte = 1,099,511,627,776 Bytes
1 Petabyte (PB) = 1,125,899,906,842,624 Bytes
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Memory – Cont’d.
Elements of
a Personal Computer
11. • Group of integrated circuits responsible for:
− Starting computer
− Checking RAM
− Loading operating system
• Occurs only when computer first turned on or each time you restart (reboot)
computer
• Reads information entered and processes it during time it resides in memory
− When process complete, clears itself and waits for next entry
− Does not perform any tasks other than reads information and
processes it
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Read Only Memory (ROM) BIOS
Elements of
a Personal Computer
12. • Located in system unit as electronic memory pool where computer holds copies
of programs and data
• Temporarily stores software program currently using and data created in
program; may be referred to as system RAM
• RAM is volatile
• Measured in nano seconds (ns)
• Used in video display cards or to buffer information sent to printer
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Random Access Memory (RAM)
Elements of
a Personal Computer
13. 1. ROM BIOS takes control when computer started and loads operating system
2. When operating system gains control, see Windows “splash screen”
− Operating system checks Windows “registry,” which identifies what
hardware and software installed
− When complete, see Windows “desktop”
3. Certain amount of RAM used to run basic files
− As computer performs specific tasks, it uses RAM needed
− When starting software “application” or program, asking computer to put
copy of program in RAM
− Close application program when not in use to make RAM available
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Understanding How Memory Works
Elements of
a Personal Computer
14. 14
• RAM is temporary so you must save work to storage device
• Storage device you use depends on amount of storage you need and speed of
data retrieval or data transfer rate
• Hard disk drives used most often to store and retrieve software programs and
data
• Can use other media such as flash drive or optical disc for backup or
portability purposes
What are storage systems?
Working with storage
systems
15. • Disk drive performs three functions:
− Rotates disk at constant speed to access sectors on entire disk surface
− Moves read/write head across tracks on entire disk surface
− Reads data from disk and writes data to disk using read/write head
• Data from RAM written on disk arranged in tracks divided in sectors
• Process of preparing disk for use is called formatting
− Places special information on each track that marks location of each sector
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Disk Drivers
Working with storage
systems
16. • Primary storage area for both data and programs
− Software programs must be installed on hard drive
− Hard drive stores and retrieves information at high speeds
• Data transfer rate (throughput) of hard drive is function of hard drive rotation
speed and number of heads per surface
− The higher the rotation speed and/or number of heads,
the less time it takes to find data
− Range in capacity from 100 MB to 100+ GB
− Also used in network servers where drives very large to accommodate
requirements of whole organization and data storage requirements
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Hard Disk Drivers
Working with storage
systems
17. • Designed to read flat, circular disc, commonly referred to as Compact Disc
(CD) or Digital Versatile/Video Disc (DVD)
− Read by laser device or optical drive that spins disc at speeds from
200 rpm or higher
• CD-ROM (Compact Disc Read Only Memory) or DVD-ROM drive
− Similar to player in audio/video entertainment system
− Information written or burned onto surface and retrieved with laser beam
− Can only read data
• New computers come with at least one optical drive
− Usually DVD optical drive or CD/DVD optical writer drive.
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Optical Drivers
Working with storage
systems
18. 18
• Also known as burner drive, looks and acts like regular optical disc drive
− Software comes with optical writer drive to “burn” or write data onto a disc
• Formats of drives include:
− CD-R/ DVD-R: can write once only to blank disc, but disc can be read
multiple times
− CD-RW/ DVD-RW: can read and write multiple times onto same disc
− DVD-RAM: similar to DVD-RW but can only be used on devices that
support this format; usually in the form of cartridges
• Blank discs relatively inexpensive, with -R disks cheaper than -RW
• Size of disc can be 650 or 700 MB, while DVDs can be 4.7GB to 17+GB with
rapid access speeds
• Special software needed to manipulate or edit video before burned to DVD
Optical Writers
Working with storage
systems
19. • Removable media systems can include flash memory cards, sticks or USB
flash key/thumb drives, or external hard drives
− Benefits include portability, large storage size, and data-sharing
capability
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Removable storage devices
Working with storage
systems
20. 20
Hardware
Using Input/output
devices
• The physical parts of a computer are collectively known as hardware.
• Internal hardware is located within the main box (system unit) of
the computer.
• External hardware is located outside the system unit and plug into
connectors called ports located on the exterior of the system unit.
21. • Enables communication between user and computer
• Three classifications of Input/output devices:
− Send information to computer
− Display or transmit information from computer
− Communicate between computers
• Input device
− Anything used to enter data into computer
• Output device
− Anything used to display data on or from computer
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Input/output Devices
Using Input/output
devices
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Software
Using Input/output
devices
• The programs or instructions used to tell the computer hardware what to do.
• System software allows a computer to operate and run application software.
• Application software performs specific tasks or applications.
26. • Device driver
− Mini-program tells operating system what kind of device it is, what make or
brand it is, and its purpose
− Main purpose is to enable communication between operating system and device
• Plug-and-play
− Automatically identifies new device connected so it looks for and installs device
automatically
− If cannot find right driver, will need to use software that came with device or
search for driver on Internet
• Important to have correct driver for device to work properly
− If special features included with device, correct driver ensures features will be
available
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Device Driver
Using Input/output
devices
27. 27
Software Copyright
Using Input/output
devices
• Software copyright is the extension of copyright law to machine-readable
software.
• Software copyright is used by proprietary software companies to prevent
the unauthorized copying of their software.
• free and open source licenses also rely on copyright law to enforce their
terms.
• A copyleft is a type of copyright license that allows redistributing the work
(with or without changes) on condition that recipients are also granted
these rights.
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Software Copyright
(Freeware & Shareware)
Using Input/output
devices
• Freeware is copyrighted computer software which is made available for use
free of charge, for an unlimited time. Freeware refers to software that anyone
can download from the Internet and use for free.
• Shareware refers to commercial software that is copyrighted, but which may
be copied for others for the purpose of their trying it out with the
understanding that they will pay for it if they continue to use it. Sharewares
give users a chance to try the software before buying it.
