Title: Introduction To Computer System
1Introduction To Computer System
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2Computer Generations
- First
- Second
- Third
- Fourth
3Computer Generations
4The First Transistor (1948)
5IBM 360 Computer System
6IBM 704
Used discrete transistors
7IBM 709 Mainframe
Last of the vacuum tube computers, c. 1959
8Digital Equipment Corp
Left DEC PDP-8, c. 1965 Right DEC PDP-11, c.
1970
9Computer
- What is the Computer ?
- The Computer is a set of independent physical
components and devices (Hardware), which have a
specific job to do for each one and working
together by Software to make up the computer
system. - Computer perform three main operations
10Computer Classifications (types)
- Microcomputer
- Minicomputer
- Mainframe
- Supercomputer
11Microcomputer
- Users One
- Speed Slow
- Price 500 - 3,000
- Size desktop or smaller
- Examples IBM PC, Apple , Apple Macintosh,
Imac - personal computers
12Minicomputer
- Users 2 - 50
- Speed Faster
- Price 10,000 - 250,000
- Size file cabinet
- Examples HP 9000
- DEC VAX
- departmental computers
13Mainframe Computer
- Users 50
- Speed Fast
- Price 500,000 - millions
- Size refrigerator-sized on up
- Examples IBM 3090, Unisys 2200
- company-wide (enterprise)
14Supercomputer
- Users a few
- Speed very, very fast
- Price millions
- Size room
- Examples Cray, Fujitsu
- scientific uses
15Understand the Terms Intelligent and Dumb
Terminal.
- An intelligent terminal, for example a PC -
- Performs a lot of the processing locally
- You could use a PC, linked to a mainframe
- A dumb terminal -
- Has very limited processing capabilities itself,
but allows you to connect to a large powerful
computer such as a mainframe. - When you process your data from the dumb
terminal, it is the mainframe at the other end of
the network that is performing all the
calculations.
16Look inside the computer
SOFTWARE
HARDWARE
17Computers are made of
18Hardware
19Hardware
- The parts of computer itself (tangible objects )
including - CPU (or Processor) and Primary memory (or Main
Memory) - Input devices i.e the keyboard and mouse
- Output devices
- Storage devices
20The Case (System Unit or System Cabinet)
21Hardware
- Central Processing Unit (CPU)
- Input units
- Output units
- Memory (Main or Primary Memory Secondary or
Auxiliary Memory)
22Components of a Computer System
Central Processing Unit (CPU)
Data
control unit (CU)
Memory
output units
Arithmetic logic Unit (ALU)
RAM
Input units
ROM
Auxiliary Memory
Information/Knowledge
23Hardware Organization
Input Devices ...
CPU
memory
motherboard
hard drive
24Input Devices
- Translate data from form that humans understand
to one that the computer can work with - Most common are keyboard and mouse
25Examples of Input Devices
- 1. Keyboard
- 2. Mouse
- 3. Scanner
- 4. Pre-storage Devise (Disk, CDs, etc.)
- 5. Optical mark recognition (Light Pin , Bar
code scanners) - 6. Microphone
- 7. Joystick .
26Examples of Input Devices(2)
- 8. Point and Draw devices
- 9. Trackball
- 10. Touchpad
- 11. Touch screen
- 12. Magnetic stripes and smart cars.
- 13. Digital Cameras
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28Hardware Organization
CPU
memory
hard drive
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29Mother-Board (or Main Board)
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CPU
RAM
ROM
30Hardware Organization
CPU
memory
motherboard
hard drive
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31Central Processing Unit (CPU)
- A specific chip or the processor
- a CPU's performance is determined by the rest of
the computers circuitry and chips. - The Central Processing Unit (CPU) performs the
actual processing of data - The speed (clock speed) of CPU measured by Hertz
(MHz)
32- The CPU consists of
- Control Unit (CU)
- Arithmetic and Logical Unit (ALU)
- Some Registers
33Central Processing Unit (CPU)
Central Processing Unit (CPU)
Control Unit (CU)
Arithmetic Logic Unit (ALU)
Registers
34- The Control Unit (CU)
- coordinates all activities of the computer by
- Determining which operations to perform and in
what order to carry them out. - The CU transmits coordinating control signals to
other computer components.
35- The ALU
- consists of electronic circuitry to perform
- Arithmetic operations (addition, subtraction,
multiplication and division) - Logical operations (and, or, not, ) and to make
some comparisons (less-than, equal, etc.)
36Hardware Organization
CPU
memory
motherboard
hard drive
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37Primary Memory
- Memory (fast, expensive, short-term memory)
Enables a computer to store, at least
temporarily, data, programs, and intermediate
results. - Two general parts
- RAM
- ROM
38Know How Computer Memory Is Measured
- Bit
- All computers work on a binary numbering system,
i.e. they process data in one's or zero's. This
1 or 0 level of storage is called a bit. - Byte
- A byte consists of eight bits.
- Kilobyte
- A kilobyte (KB) consists of 1024 bytes.
- Megabyte
- A megabyte (MB) consists of 1024 kilobytes.
- Gigabyte
- A gigabyte (GB) consists of 1024 megabytes.
39Main Memory
40RAM (Main Memory)
- its a primary storage or random access memory
(RAM). - it temporarily holds data and programs for use
during processing (volatile) - Any information stored in RAM is lost when the
computer is turned off. - RAM is the memory that the computer uses to
temporarily store the information as it is being
processed. The more information being processed
the more RAM the computer needs. - RAM consists of locations or cells. Each cell
has a unique address which distinguishes it from
other cells.
41ROM Read Only Memory
- ROM is part of memory
- Programmed at manufacturing time
- Its contents cannot be changed by users
- It is a permanent store
- Q Mention some examples of ROM?
- A (PROM EPROM )
42Other Kind of Memory
- PROM Programmable Read Only Memory.
- EPROM Erasable Programmable Read Only Memory
- Cache Memory
- Registers not part of the main memory.
- Q Registers are part of ?
43Secondary Storage
- Stores data and programs permanently its
retained after the power is turned off - Examples
- Hard Drive (Hard Disk)
- Located outside the CPU, but most often
contained in the system cabinet - Floppy Disk
- Optical Laser Discs
- CD-ROM, CD-RW, and DVD
44Kinds of Disk Drives
45Common Secondary Media
- Diskettes
- Data represented as magnetic spots on removable
flexible plastic disks - Most common size is 3 1/2 inches, in a rigid
plastic case - Disk drive holds the diskette, reads or retrieves
the data and writes or stores data
46Common Secondary Media
- Hard drive
- Data is represented magnetically as with
diskettes - Normally more than one rigid platter in a sealed
unit - These disks are not removable
- Significantly more capacity and faster operating
than diskettes
47 Optical Laser Discs
- CD ROM DVDs
- Data is represented as pits and lands
- Some kinds are read only (CD-ROM) and some Kinds
are rewritable (CD-RW) - Significantly more capacity and faster operating
than diskettes
DVD Digital Video Disk
48Common Secondary Media
Approximate printed 8.5 x 11 inch pages Amount of storage Disk size
180 pages 360 Kb 5.25 low density
360 pages 720 Kb 3.5 low density
600 pages 1.2 Mb 5.25 high density
720 pages 1.44 Mb 3.5 high density
a small library 700 MB CD
a feature length movie 8.5 GB DVD
49Common Secondary Media
- tapes
- Panasonic's LS120 3.5 inch diskettes
- Iomega's Zip Jazz disks
- VCR tape (Video Cassette Recorder )
- Flash USB disks
- MMC (Multi Media Card )
- SD
50Hardware Organization
CPU
memory
hard drive
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Output
51CPU
Output Devices
Pieces of equipment that translate the processed
information from the CPU into a form that humans
can understand.
Processed information
52Output Devices
- Monitors
- Printers
- Dot matrix printers
- Ink jet printers
- Laser printers
- Sound Blasters (Sound Card By Creative Lab)
- Controlling other devices
53Software
- The instructions that tell the computer what to
do - Application Software - helps end-users perform
general purpose tasks - System Software - enables application software to
interact with the computer
54System Software
- The most important
- System Software
- is the
- Operating System
- Examples of operating systems
- Windows XP, DOS, Apple, UNIX
55System Software
- The software that controls everything that
happens in a computer. - Background software, manages the computers
internal resources
Resources examples CPU, RAM , I/O devices,
56- All hardware and software are under the control
of the operating system. - Among other things, the operating system
- Determines how valuable RAM is allotted to
programs. - Performs tasks related to file management.
- Sets priorities for handling tasks.
- Manages the flow of instructions, data and
information to and from the processor (CPU).
57Examples of Microcomputer Operating System
Software
- DOS - original standard for IBM compatibles
- Windows - a graphical operating environment
- Windows VISTA, XP, millennium, 2000, 98, and 95
- Continue
58Examples of Microcomputer Operating System
Software Cont.
- Windows NT - for powerful workstations networks
- OS/2 - competitor to Windows 2000
- Macintosh Operating System
- Unix - originally for minicomputers, now used on
microcomputers and Internet servers - Question List some examples of operating systems
?
59Application Software
Packaged
Custom
- Packaged - off the shelf, pre-written programs
( General purpose) - Custom - written for an organizations specific
purpose (Special purpose)
60Application Software Basic Tools
- Word processors example Microsoft word
- Spreadsheets-- example Microsoft Excel
- Database managers-- example Microsoft Access
- Graphics-- example Photoshop
Spreadsheets Computer software that allows the
user to enter columns and rows of numbers in a
accounting book like format.