Computer fundamentals brr
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Transcript of 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.