Graded Discussion board
Pro-tech software house is currently working on a project of developing a “Printer Management system”. The scope of this project is limited due to which this project was scheduled to complete in only 3 months. There was a limited set of requirements for this project given by client. With passage of time the requirements are changing for this project, but to very limited extent. Due to changing requirements the project scheduled time is now increased from 3 months to 4 months.
Being a member of requirement engineering team do you think that requirement traceability is vital for such a limited scope project? Discuss your answer with proper reasons.
A concise, coherent and to the point comment is preferred over lengthy comment having irrelevant details. Your comment must not be more than 4-5 lines. Comments, posted on regular Lesson's MDB or sent through email will NOT be considered in any case. Any request about such an acceptance will not be catered.
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Who is Charles Babbage (1791-1871)
· Creator of the Analytical Engine - the first general-purpose digital computer (1833)
The Analytical Engine
A programmable, mechanical, digital machine
Could carryout any calculation
Could make decisions based upon the results of the previous calculation
Components: input; memory; processor; output
Ada, Countess Of Lovelace(1815-52)
Babbage: the father of computing
Ada: the mother?
Wrote a program for computing the Bernoulli’s sequence on the Analytical Engine - world’s 1st computer program
Ada: A programming language specifically designed by the US Dept of Defense for developing military applications was named Ada to honor her contributions towards computing
A Lesson That We All Can Learn From Babbage’s Life
Charles Babbage had huge difficulties raising money to fund his research
As a last resort, he designed a clever mathematical scheme along with Ada, the Countess of Lovelace
It was designed to increase their odds while gambling. They bet money on horse races to raise enough money to support their research experiments
Guess what happened at the end? The lost every penny that they had.
In 1997 Deep Blue, a supercomputer designed by IBM, beat Gary Kasparov, the World Chess Champion
That computer was exceptionally fast, did not get tired or bored. It just kept on analyzing the situation and kept on searching until it found the perfect move from its list of possible moves …
The “Turing test”
A test proposed to determine if a computer has the ability to think. In 1950, Alan Turing (Turing, 1950) proposed a method for determining if machines can think. This method is known as The Turing Test.
Vacuum Tube – 1904
A vacuum tube is just that: a glass tube surrounding a vacuum (an area from which all gases has been removed). A British scientist named John A. Fleming made a vacuum tube known today as a diode. Then the diode was known as a "valve,"
ABC – 1939
The Atanasoff-Berry Computer was the world's first electronic digital computer. It was built by John Vincent Atanasoff and Clifford Berry at Iowa StateUniversity during 1937-42.
Harvard Mark 1 – 1943
Howard Aiken and Grace Hopper designed the MARK series of computers at Harvard University. clicking metal parts, 55 feet long and 8 feet high. The 5-ton device contained almost 760,000 separate pieces. Used by the US Navy for gunnery and ballistic calculations, the Mark I was in operation until 1959.
ENIAC – 1946
ENIAC (Electrical Numerical Integrator AndCalculator). The U.S. military sponsored their researchIt took the team about one year to design the ENIAC and 18 months and 500,000 tax dollars to build it. The ENIAC contained 17,468 vacuum tubes, along with 70,000 resistors and 10,000 capacitors.
The first transistor was invented at Bell Laboratories on December 16, 1947 by William Shockley. Compared to vacuum tubes, it offered:
lower power consumption
Floppy Disk – 1950:
Invented at the Imperial University inTokyo by Yoshiro Nakamats.
UNIVAC 1 – 1951
The first commercially successful electronic computer, UNIVAC I, was also the first general purpose computer - designed to handle both numeric and textual information. It was designed by J. Presper Eckert and John Mauchly.
Compiler – 1952
Grace Murray Hopper an employee of Remington-Rand worked on the NUIVAC. She took up the concept of reusable software in her 1952 paper entitled "The Education of a Computer" and developed the first software that could translate symbols of higher computer languages into machine language. (Compiler)
ARPANET – 1969
ARPA was assigned to research how to utilize their investment in computers via Command and Control Research (CCR). Dr. J.C.R. Licklider was chosen to head this effort. Developed for the US DoD Advanced Research Projects Agency
Intel 4004 – 1971
The 4004 was the world's first universal microprocessor.
Altair 8800 – 1975
Developers Edward Roberts, William Yates and Jim Bybee spent 1973-1974 to develop the MITS (Micro Instruments Telemetry Systems ) Altair 8800. The price was $375, contained 256 bytes of memory (not 256k),but had no keyboard, no display, and no auxiliary storage device.
Cray 1 – 1976
The Cray 1 was the world's first "supercomputer," a machine that leapfrogged existing technology when it was introduced in 1971.
IBM PC – 1981
On August 12, 1981, IBM released their new computer, re-named the IBM PC. The "PC" stood for "personal computer" making IBM responsible for popularizing the term "PC".
The first IBM PC ran on a 4.77 MHz Intel 8088 microprocessor. The price tag started at $1,565, which would be nearly $4,000 today.
Apple Macintosh – 1984
Apple introduced the Macintosh to the nation onJanuary 22, 1984. The original Macintosh had 128 kilobytes of RAM, although this first model was simply called "Macintosh" until the 512K model came out in September 1984. The Macintosh retailed for $2495.
World Wide Web -1989
WWW quickly gained great popularity among Internet users.
What is World Wide Web?
· A huge resource of information
· Logically unified: Any one from any where can access the information using a very simple scheme consisting of links & URLs
· Physically distributed: The information is stored on Internet-connected computers that are spread all over the globe
A browser is an application program that provides a way to look at and interact with all the information on the World Wide Web.
URL (Uniform Resource Locator, previously Universal Resource Locator) – pronounced YU-AHR-EHL or, in some quarters, UHRL - is the address of a file (resource) accessible on the Internet.
How many Web pages are there?
In 1999 there were 800 million Web pages (15 terra (1012) bytes of text)
In year 2002, the number is supposed to be 8 billion
If you spend a minute reviewing each of these pages, it will take more than 15,000 years to go through them all
What is secret behind the explosive growth of the Web?
Anarchy – any page is allowed to link to any other
There are no controls over who puts what on the Web
Everyone can put whatever they want to put on the Web – and they do!
The most popular Web sites?
• AOL – Most popular ISP’s Web site
Microsoft – Most popular software developer’s Web site
Yahoo – Most popular multi-service Web site
Amazon – most popular shop on the Web
CNN – most popular news Web site
Google – most useful search engine
CS101 SHORT NOTES PART 2Recommended: CS101 Mid Term 16 SOlved Papers + Quizzes + Solved Subjectives + HTML TAGS
What is a Web Site?
A Web site is a related collection of World Wide Web (WWW) files that includes a beginning file called a home page.
What is a Web Search Engine?
· Search engines continuously scan the Web and compile a list of all the Web pages that they find
Internet & Web
The “Internet” and the “Web” are not the same
In fact, the “Web” is a service that runs over the “Internet”. In addition to the Web, there are many other services that run over the Interne.
Internet is like the network of roads in a city, whereas Web is a service like the Bus Service that run over those roads. Just like other services can use the roads (e.g. wagons),
Info is available on Web
Information about almost every thing known to mankind and then some!
The info is in the form of:
The Semantic Web
What unique feature distinguishes the Web of today with the Semantic Web of tomorrow?
Whereas, today’s Web’s content is designed for humans to read; the Semantic Web’s content will be designed for computers to understand meaningfully
However, the Semantic Web is not a replacement but an extension of the present Web, in which information is given well defined meaning
Some progress is already being made for adding “Semantic Content” on to the Web, but a lot more will happen in the next 5 years
Computer types according to capability are
State-of-the-art machines designed to perform calculations as fast as the current technology allows
Used to solve extremely complex and large-scale problems: weather prediction, simulation of atomic explosions; aircraft design; movie animation
Cost tens of millions of dollars
The Champion: ASCI White
Most powerful computer as of February 2002
Capable of 12.3 trillion calculations/sec
- 74,000 times faster than Cray 1 (1976)
- 1,000 times faster than Deep Blue (1997)
Designed for complex 3-D simulations required for testing nuclear weapons
Powered by 8192 microprocessors
6 TB of memory; 160 TB of storage capacity
Also called “Enterprise Servers”
Designed for performing multiple, intensive tasks for multiple users simultaneously
Used by large businesses (e.g. banks, e-commerce sites), military, and industrial organizations
Designed for very-high reliability
Cost in millions of dollars
The name minicomputers used to define the class of computers that lies between personal computers and mainframes
Generally are more reliable than desktops, but not as solid as the mainframes
Costs in hundreds of thousands of dollars
Also called microcomputers
Low-end desktops are called PC’s and high-end ones “Workstations”
· PC’s are used for running productivity applications, Web surfing, messaging
· Workstations cost a few thousand dollars; PC around a $1000
Laptops, palmtops, and wearable computers are very capable computers but are light-weight and consume very little power
also called notebook computers
generally weigh around 2kg
use special low-power processors
typically have 256MB memory,
40GB of storage
can work for more than 2 hours on battery.
Their usage is similar to that of PCs
They cost in the range of $1500-2500
also known as PDA’s - Personal Digital Assistants
Weigh less than a pound
have very low-power processors
KB’s of memory
MB’s of storage capacity
Can run for many hours on AA batteries
Used as an electronic version of a pocket diary
Also for Web surfing and e-mail or even as mobile phones
Palmtops cost $200-600
are small in size
carried in a pocket
worn on the arm, waist
or head or elsewhere on the body
Capability similar to PDA’s
but more expensive
They are always ON, and always accessible. That is, the user can always enter and execute commands, even while walking around or doing other activities
Each soldier of the future will be fitted with one
Ranking w.r.t. installed number
Wearables (will take the top spot in future)
Essential Hardware Components
At the highest level, two things are required for computing
Hardware: The physical equipment in a computing environment such as the computer and its peripheral devices (printers, speakers, etc.)
Software: The set of instructions that operates various parts of the hardware. Also termed as “computer program
All computers have the following essential hardware components:
The devices used to give the computer data or commands are called Input devices. Includes keyboard, mouse, scanner, etc
A processor is the logic circuitry that responds to and processes the basic instructions that drive a computer.
Memory is the electronic holding place for instructions and data that your computer's microprocessor can reach quickly.
Computer storage is the holding of data in an electromagnetic form for access by a computer processor.
The devices to which the computer writes data are called Output devices
A mouse is a small device that a computer user pushes across a desk surface in order to point to a place on a display screen and to select one or more actions to take from that position. Keyboard
On most computers, a keyboard is the primary text input device. A keyboard on a computer is almost identical to a keyboard on a typewriter.
In computers, a joystick is a cursor control device used in computer games.
A digital camera records and stores photographic images in digital form that can be fed to a computer as the impressions are recorded or stored in the camera for later loading into a computer or printer. Currently, Kodak, Canon, and several other companies make digital cameras.
A device that converts sound waves into audio signals. These could be used for sound recording as well as voice chatting through internet.
A scanner is a device that captures images from photographic prints, posters, magazine pages, and similar sources for computer editing and display.
CS101 SHORT NOTES PART 3Recommended:CS101 Latest Solved MCQs
What is a Port?
On computer and telecommunication devices, a port(noun) is generally a specific place for being physically connected to some other device, usually with a socket and plug of some kind.
Many Types of Ports
An interface on a computer that supports transmission of multiple bits at the same time; almost exclusively used for connecting a printer.
It is a general-purpose personal computer communications port in which 1 bit of information is transferred at a time.
A port that's faster than the serial and parallel ports but slower and harder to configure than the newer USB port. Also know as the Small Computer System Interface.
USB (Universal Serial Bus) is a plug-and-play hardware interface for peripherals such as the keyboard, mouse, joystick, scanner, printer and modem.
FireWire is simply a really fast port that lets you connect computer peripherals and consumer electronics to your computer without the need to restart.
RAM (random access memory) is the place in a computer where the operating system,
A card on which data can be recorded in the form of punched holes
ROM is "built-in" computer memory containing data that normally can only be read, not written to. Hard disk
Hard disk is a computer storage device which saves and retrieves the data when required. Floppy disk
A diskette is a random access, removable data storage medium that can be used with personal computers.
In computers, tape is an external storage medium, usually both readable and writable, can store data in the form of electromagnetic charges that can be read and also erased.
A compact disc [sometimes spelled disk] (CD) is a small, portable, round medium for electronically recording, storing, and playing back audio, video, text, and other information in digital form.
DVD (digital versatile disc) is an optical disc technology that is expected to rapidly replace the CD-ROM disc (as well as the audio compact disc) over the next few years. The digital versatile disc (DVD) holds 4.7 gigabyte of information on one of its two sides, or enough for a 133-minute movie.
Electronic (RAM, ROM)
Magnetic (HD, FD, Tape), optical (CD, DVD)
Volatile (RAM), non-volatile (HD)
Direct access (RAM, HD), serial access (Tape)
Read/write (HD, RAM), read-only (CD)
Modem is output as well as input device at the same time.
Backside ports, fan, slots, cables
Power supply/fan & connectors
The Processor Module
The slot on the motherboard
Pins (256?), Transistors (10 million?)
Hyper Text Markup Language
<TITLE>Virtual Study Solutions Home Page</TITLE>
<H1>Virtual Study Solutions</H1>
<P><B>Adjunct Lecturer in Computer Science</B><BR>
<A HREF="http://www.vu.edu.pk/">Virtual University</A><BR>
Building 1, 3rd Floor, Aiwan-e-Iqbal, Lahore<BR>
+92 42 555 1212<BR>
<P>I teach the <A HREF="http://www.vu.edu.pk/cs101/">Introduction to Computing</A> course. </P>
A microprocessor (abbreviated as µP or uP) is a computer processor on a microchip. It's sometimes called a logic chip. A microprocessor is designed to perform arithmetic and logic operations that make use of small number-holding areas called registers.
Commonly known as an IC or a chip
A tiny piece of Silicon that has several electronic parts on it
Components of integrated are
And are made of the following materials
Silicon - semiconductor
Copper - conductor
Silicon Dioxide - insulator
A Microprocessor System
Microprocessors are powerful pieces of hardware, but not much useful on their own
A microcomputer is 1 example of a microprocessor system
Micro-controllers are another type of microprocessor systems
They are generally not that powerful, cost a few dollars a piece, and are found embedded in video games, VCRs, microwave ovens, printers, autos, etc.
The Main Memory Bottleneck
Modern super-fast microprocessors can process a huge amount of data in a short duration
They require quick access to data to maximize their performance
On-Chip Cache Memory
That small amount of memory located on the same chip as the microprocessor is called On-Chip Cache Memory
Bus Interface Unit
The bus interface unit is the part of the processor that interfaces with the rest of the PC.
The instruction decoder of a processor is a combinatorial circuit sometimes in the form of a read-only memory,
A decoder is a device which is the reverse, undoing the encoding so that the original information can be retrieved.
Microprocessor Building Blocks
Arithmetic & Logic Unit (ALU)
An arithmetic and logical unit (ALU) also known as“Integer Unit” is one of the core components of all central processing units.
Floating-Point Unit (FPU)
A floating point unit (FPU) is a part of a CPU specially designed to carry out operations on floating point numbers
A register is a device for storing data. It is a small amount of very fast computer memory used to speed the execution of computer programs by providing quick access to commonly used values.
Data registers are used to store integer numbers.
Address registers hold memory addresses and are used to access memory.
General Purpose registers can store both data and addresses.
Floating Point registers are used to store floating point numbers.
Constant registers hold read-only values (e.g zero or one).
Vector registers hold data for Single Instruction Multiple Data (SIMD) instructions.
Special Purpose registers which store internal CPU data like the stack pointer or processor status words.
A control unit is the part of a CPU or other device that directs its operation. The outputs of the unit control the activity of the rest of the device. A control unit can be thought of as a finite state machine. It is called the brain of computer microprocessor.
The set of machine instructions that a microprocessor recognizes and can execute – the only language microprocessor knows
The 1st microprocessor : Intel 4004
108 kHz, 60,000 ops/sec
Cost: less than $100
Currently Popular Intel Pentium 4 (2.2GHz)
Introduced December 2001
55 million transistors
32-bit word size
2 ALU’s, each working at 4.4GHz
0.13 micron process
Targeted use: PC’s and low-end workstations
Cost: around $600
In 1965, one of the founders of Intel – Gordon Moore – predicted that the number of transistor on an IC (and therefore the capability of microprocessors) will double every year. Later he modified it to 18-months
Enhancing the capability of a microprocessor
The computing capability of a microprocessor can be enhanced in many different ways:
By increasing the clock frequency
By increasing the word-width
Improving the architecture