Lecture 1 - Computer Systems Outlinehusaingholoom.com/files/1319/CS1319_Lecture1.pdfThird Generation Software (1965-1971) • Systems Software – utility programs, – language translators,

CS 1319 - Husain Gholoom –lecturer in Computer Science Page 1

Lecture 1 - Computer Systems

Outline

• Describe the layers of a computer system.

• Computing systems.

• Explain the five parts of an information system: people, procedures, software, hardware, and data.

• Distinguish between system software and application software.

• Discuss the three kinds of system software programs.

• Distinguish between basic and specialized application software.

• Identify the four types of computers and the four type of microcomputers.

• Describe the different types of computer hardware including the system unit, input/output, secondary storage, and communication devices.

• Define data and describe document, worksheet, database, and presentation files.

• Explain computer connectivity, the wireless revolution, the Internet, Smartphone, and cloud computing.

• Describe the history of computer hardware and software

• Describe the changing role of the computer user

• Distinguish between systems programmers and applications programmers

• Distinguish between computing as a tool and computing as a discipline


Computing systems are dynamic!

• Constant Modification, Revision, Correction of Hardware and Software

• Expansion of Hardware and Software Capabilities

• Maturation and Extension of Concepts

• Simplification of Procedures

• Improvements in Human Computer Interface


Computing Systems : Hardware : The physical elements of a computing system (Mother board, disk drive, memory, controller cards, power supply, communication ports, bus, monitor, keyboard, etc.) Software : The programs that provide the instructions for a computer to execute (boot program, assembler, compiler, operating system, applications, function library, browser, etc.)

Layers of a Computing System


Five Parts of an Information System

• People

• Procedures

• Software

• Hardware

• Data


People

• Most important part of any system

• Contact is … o Direct o Indirect


Computer uses

o Business & Entertainment o Education & Medicine

Software : Software is another name for programs

Two major kinds of software

System Software : A collection of programs – not a single program .

o Includes Operating System software, Utilities, and Device Drivers

o Enables the application software to interact with the hardware, and helps the computer manage its resources

o Two best-known operating systems for microcomputers are Windows 7 and Mac OS X


Application Software

o End-user software o Two major categories

▪ Basic applications ▪ Specialized applications


Hardware - Types of Computers

o Supercomputers o Mainframe computers o Minicomputers (or mid-range computers) o Microcomputers


Microcomputer Types

o Desktop o Media center system units o Notebook or laptop o Netbooks o Tablet PC o Handheld

Desktop Computers

o Desktop computers are small enough to fit on top of or alongside a desk, yet are too big to carry around


Media Center System Units

o Media center system units blur the line between desktop computers and dedicated entertainment devices

Notebook or Laptop Computers

o Notebook computers, also known as laptop computers, are portable, lightweight, and fit into most briefcases

Netbooks

o Similar to notebook computers, but … – Smaller - Lighter - Less expensive


Tablet PC

o In addition to a keyboard, a tablet PC allows you to enter data, write notes, and select commands using a pen stylus

o Handwritten data is digitized and converted to standard text that can be further processed by a word processor


Handheld

o Handheld or palm computers, such as Personal digital assistants (PDAs) and smartphones, are amongst the smallest computing devices

o These systems typically combine pen input, writing recognition, personal organizational tools, and communications capabilities

o Smartphones are cell phones with wireless connections to the Internet


Microcomputer Hardware

o Four basic categories of equipment: ▪ System Unit ▪ Input/Output ▪ Secondary Storage ▪ Communications


System Unit

o Two important components ▪ Microprocessor ▪ Memory


Input/Output Devices

o Common input devices are the keyboard and the mouse o Common output devices are printers and monitors


Secondary Storage

o Unlike memory, secondary storage holds data and programs even if electrical power is not available

o The most important types of secondary media are hard disks, solid-state storage, and optical disks

Communications

o Communication devices, such as modems, provide microcomputers with the ability to communicate with other computer systems across the globe

o Modems modify telephone communications into a form that can be processed by a computer

o Modems also modify computer output into a form that can be transmitted across standard telephone lines


Data

o Raw, unprocessed facts o Processed data becomes information o Digital data is stored electronically in files

▪ Document files ▪ Worksheet files ▪ Database files ▪ Presentation files

Document Files

o Created by word processors to save documents such as memos, term papers, and letters

Worksheet Files

o Created by electronic spreadsheets to analyze things like budgets and to predict sales

o Database Files o Typically created by database management programs to

contain highly structured and organized data


Database Files

o Typically created by database management programs to contain highly structured and organized data


Presentation Files

o Created by presentation graphics programs to save presentation materials. For example, a file might contain audience handouts, speaker notes, and electronic slides.


Connectivity, the Wireless Revolution, the Internet, and Cloud

Computing

o Connectivity ▪ Sharing of information ▪ Wireless communication has widespread use

o Computer networks ▪ Connected communication system of computers ▪ Largest network is the Internet

o Cloud Computing ▪ Uses the Internet and the Web to shift many computer

activities from a user’s computer to computers on the Internet

Careers in IT

A Look to the Future

o The Internet and the Web o Powerful Software o Powerful Hardware o Security and

Privacy o Organizations o Changing Times


Early History of Computing

Abacus : A device to record, add and subtract numeric values using a modified

base 5 notation.

Blaise Pascal

Mechanical device to add, subtract,

divide & multiply


Joseph Jacquard

Jacquard’s Loom, the punched card

Charles Babbage Analytical Engine

It was first described in 1837 as the successor to Babbage's

Difference Engine, a design for a mechanical computer.

The Analytical Engine incorporated an

arithmetic logic unit, control flow in the form

of conditional branching and loops, and

integrated memory, making it the first

design for a general-purpose computer that

could be described in modern terms as

Turing-complete.

Ada Lovelace - First Programmer, the loop

Ada Lovelace described and published an algorithm for Charles

Babbage's analytical engine to computer Bernoulli numbers.

It is generally considered the first algorithm ever specifically

tailored for implementation on a computer, and for this

reason she is considered by many to be the first computer

programmer.

http://en.wikipedia.org/wiki/Difference_Engine

http://en.wikipedia.org/wiki/Arithmetic_logic_unit

http://en.wikipedia.org/wiki/Control_flow

http://en.wikipedia.org/wiki/Conditional_branching

http://en.wikipedia.org/wiki/Program_loop#Loops

http://en.wikipedia.org/wiki/Computer_memory

http://en.wikipedia.org/wiki/Turing-complete

http://wiki.answers.com/Q/What_did_Ada_Lovelace_invent


Alan Turing - Turing Machine, Artificial Intelligence Testing Alan Mathison Turing, 23 June 1912 – 7 June 1954),

was an English mathematician, logician, cryptanalyst,

and computer scientist. He was highly influential in the

development of computer science, giving a formalization

of the concepts of "algorithm" and "computation"

with the Turing machine, which can be considered a model

of a general purpose computer. Turing is widely considered

to be the father of computer science and

artificial intelligence. Harvard Mark I, ENIAC, UNIVAC I Early computers launch new era in mathematics, physics, engineering and economics

First Generation Hardware (1951-1959)

Vacuum Tubes Large, not very reliable, generated a lot of heat Magnetic Drum Memory device that rotated under a read/write head Card Readers → Magnetic Tape Drives Sequential auxiliary storage devices


Second Generation Hardware (1959-1965)

Transistor

Replaced vacuum tube, fast, small, durable, cheap Magnetic Cores Replaced magnetic drums, information available instantly Magnetic Disks Replaced magnetic tape, data can be accessed directly

Third Generation Hardware (1965-1971)

Integrated Circuits - Replaced circuit boards, smaller, cheaper, faster, more reliable. Transistors - Now used for memory construction Terminal - An input/output device with a keyboard and screen

Fourth Generation Hardware (1971-?)

Large-scale Integration - Great advances in chip technology PCs, the Commercial Market, Workstations - Personal Computers were developed as new companies like Apple and Atari came into being. Workstations emerged.

Parallel Computing and Networking

Parallel Computing Computers rely on interconnected central processing units that increase processing speed. Networking With the Ethernet small computers could be connected and share resources. A file server connected PCs in the late 1980s. ARPANET and LANs → Internet


First Generation Software (1951-1959)

Machine Language Computer programs were written in binary (1s and 0s) Assembly Languages and translators Programs were written in artificial programming languages and were then translated into machine language Programmer Changes Programmers divide into application programmers and systems programmers

Second Generation Software (1959-1965) High Level Languages Use English-like statements and make programming easier. Fortran, COBOL, Lisp are examples.


Third Generation Software (1965-1971)

• Systems Software – utility programs, – language translators, – and the operating system, which decides which programs to run and when.

• Separation between Users and Hardware Computer programmers began to write programs to be used by people who did not

know how to program

Fourth Generation Software (1971-1989)

Structured Programming - Pascal, C, C++ New Application Software for Users - Spreadsheets, word processors, database management systems


Fifth Generation Software (1990- present)

Microsoft - The Windows operating system, and other Microsoft application programs dominate the market

Object-Oriented Design - Based on a hierarchy of data objects (i.e. Java)

World Wide Web - Allows easy global communication through the Internet

New Users -Today’s user needs no computer knowledge

Computing as a Tool


Computing as a Discipline

• What can be (efficiently) automated? • Four Necessary Skills

1. Algorithmic Thinking 2. Representation 3. Programming 4. Design

What do you think?

Is Computer Science a Mathematical, Scientific, or Engineering discipline?

Systems Areas of Computer Science

▪ Algorithms and Data Structures ▪ Programming Languages ▪ Architecture ▪ Operating Systems ▪ Software Methodology and Engineering ▪ Human-Computer Communication

Application Areas of Computer Science

▪ Numerical and Symbolic Computation ▪ Databases and Information Retrieval ▪ Artificial Intelligence and Robotics ▪ Graphics ▪ Organizational Informatics ▪ Bioinformatics

Documents

Lecture 1 - Computer Systems Outlinehusaingholoom.com/files/1319/CS1319_Lecture1.pdfThird Generation Software (1965-1971) • Systems Software – utility programs, – language translators,