Computer fundamentals brr

Computer Fundamentals

Miss. Bajpai R. R.

Evolution of computers : 1. Abacus • counting frame • 3000 BC - china

2. Blaise Pascal’s Adder• In 1642 Blaise Pascal, at age 19, invented the Pascaline as an

aid for his father who was a tax collector.• high cost • low accuracy

3. Charles Babbage :difference engine• By 1822 was proposed a steam driven calculating machine the

size of a room, which he called the Difference Engine.• Expensive • difficult

MARK - I• IBM Automatic Sequence Controlled Calculator (ASCC), called

the Mark I by Harvard University• electro-mechanical computer• devised by Howard H. Aiken in February 1944• built from switches, relays, rotating shafts, and clutches• 51 feet (16 m) in length, eight feet (2.4 m) in height• weight of about 10,000 pounds (4500 kg).

ABC - 1942• Atanasoff–Berry Computer - electronic digital computing

device• Inventor : John Vincent Atanasoff and Clifford Berry• was not programmable• designed only to solve systems of linear equations• card writer/reader was unreliable

Eniac- Electronic Numerical Integrator And Computer

• ENIAC was conceived and designed by John Mauchly and J. Presper Eckert of the University of Pennsylvania.

• Capable of being reprogrammed • Relatively fast• 17,468 vacuum tubes, 7,200 crystal diodes, 1,500 relays,

70,000 resistors, 10,000 capacitors

EDVAC :Electronic Discrete Variable Automatic Computer• Developed by John von Neumann• It was binary rather than decimal• was a stored program computer• EDVAC was built for the U.S. Army's Ballistics Research

Laboratory

EDSAC - Electronic Delay Storage Automatic Calculator • Earlier British computer• Was constructed by Maurice Wilkes• First commercially applied computer

UNIVAC : (UNIVersal Automatic Computer• second commercial computer produced in the United States• It was designed principally by J. Presper Eckert and John

Mauchly• was accepted by the United States Census Bureau on March

31, 1951

Generations of computers

First generations - (1942-1955)• Processing device : vacuum tube: fragile glass device which use filaments ; could

control and amplify electronic signals. • Memory : electromagnetic relays : punched cards • Programming languages : Machine and assembly language

Characteristics :• Fast• Bulky in size• Thousands of vacuum tubes that emits large amount of heat and

burnt out• High Power consumption• Frequently hardware failure due to filaments• Difficult to build and Costly • Limited use

Second generations : (1955- 1964)• Processing : Transistors invented by John bardeen , william

shockley and walter brattain at Bell lab in 1947.• Memory : magnetic cores main memory , magnetic disk ,tapes• PL : FORTRAN, COBOL, ALGOL, SNOBOL• Batch operating systems• Used in business and industry for commercials data

processing(payroll, marketing , inventory control, )

Charateristics :• More rugged and easier to handle : made of semiconductor

(germanium)material rather than glass• Highly reliable : doesn’t have filament part• Faster • Low power consumption• Small in size• Cheap • Large memory capacity• Easier to program

Third generations : (1964-1975)• Processing : integrated chips (IC’s) developed by Jack St. Clair Kilby

and Robert Noyce• Microelectronics • Made by silicon• SSI :- 10- 20• MSI:- 100• LSI :- some thousands • VLSI :- millions of components• Memory capacity : RAM can store less than 5 MB, disk space upto 10 MB

• PL : ANSI FORTRAN , COBOL• Time sharing , multiuser online systems• Software was initially free. Give rise to s/w industry• Mainframe to minicomputers(PDP-8)

Characteristics :• 1 million instructions per second• Smaller • Faster• Scientific and commercials• Don’t need manual assembly of circuits• Portable• Time sharing system allows interactive usage and

simultaneous use of multiple users• Smaller can afford these computers.

Fourth generations: (1975-1989)• Microprocessors• Hard disk• Portable magnetic tapes and floppy disks • Personal computers• Super computers• High speed Computer Networks • Operating systems with GUI• Multiprocessing OS with Concurrent executions• UNIX OS

characteristics• Small • Affordable • More powerful and reliable mainframe systems• General purpose machines• Easier to produce commercially• Rapid software development• Ex : TRS- 80, Cray-1 ,Cray-2, Cray-X/MP, Apple II, IBM PC , VAX 9000

Fifth generations : (1989 -present)• Hardware technology :• ULSI• RAID • Optical disks• Notebooks , more powerful PC’s• Powerful Servers and supercomputer • Internet• Cluster computing

• Software technology :• Micro kernel based, multithreading, distributed OS• Parallel programming• Java• WWW

Characteristics :• Portable • Cheaper• More powerful• Ex: IBM notebooks , Pentium PC’s, SUN workstations, PARAM

10000

Basic computer organization

INPUT UNIT

OUTPUT UNIT

STORAGE UNIT

TYPES OF STORAGE

CENTRAL PROCESSING UNIT

Types of computers• Supercomputer• Mainframe computer • Minicomputer• Micro computer /Personal computer• Laptop• Notebook• Palmtop

REFERENCE:• FUNDAMENTALS OF COMPUTERS:

By, P. K. Sinha.