Generations of Computers BCA– Ist Fundamentals of Computers

Evolution of Computers Blaise Pascal invented the first mechanical adding machine in 1642 Baron Gottfried Wilhelm von Leibniz invented the first calculator for multiplication in 1671 Keyboard machines originated in the United States around 1880 Around 1880, Herman Hollerith came up with the concept of punched cards that were extensively used as input media until late 1970s

Evolution of Computers Charles Babbage is considered to be the father of modern digital computers He designed “Difference Engine” in 1822 He designed a fully automatic analytical engine in 1842 for performing basic arithmetic functions His efforts established a number of principles that are fundamental to the design of any digital computer

Some Early Computers The Mark I Computer (1937-44): The IBM Automatic Sequence Controlled Calculator (ASCC), called Mark I by Harvard University's staff, was a general purpose electro-mechanical computer that was used in the war effort during the last part of World War II. The original concept was presented to IBM by Howard Aiken in November 1937. The Atanasoff-Berry Computer (1939-42): The Atanasoff–Berry computer (ABC) was the first automatic electronic digital computer. The ABC's priority is debated among historians of computer technology, because it was not programmable.

THE MARK 1 THE ABC

Some Early Computers The ENIAC (1943-46): Electronic Numerical Integrator And Computer) was the first electronic general-purpose computer. It was Turing-complete, digital, and capable of being reprogrammed to solve "a large class of numerical problems." The EDVAC (1946-52): (Electronic Discrete Variable Automatic Computer) was one of the earliest electronic computers. Unlike its predecessor the ENIAC, it was binary rather than decimal, and was a stored program compute

THE ENIAC THE EDVAC

Some Early Computers The EDSAC (1947-49): Electronic Delay Storage Automatic Calculator was an early British computer. The machine was constructed by Maurice Wilkes and his team at the University of Cambridge Mathematical Laboratory in England. EDSAC was the second electronic digital stored-program computer to go into regular service Manchester Mark I (1948): The Manchester Mark 1 was one of the earliest stored- program computers, developed at the Victoria University of Manchester from the Small-Scale Experimental Machine (SSEM) or "Baby" (operational in June 1948). It was also called the Manchester Automatic Digital Machine, or MADM

THE EDSAC THE MANCHESTER MARK 1

Some Early Computers The EDSAC (1947-49): Electronic Delay Storage Automatic Calculator was an early British computer. The machine was constructed by Maurice Wilkes and his team at the University of Cambridge Mathematical Laboratory in England. EDSAC was the second electronic digital stored-program computer to go into regular service Manchester Mark I (1948): The Manchester Mark 1 was developed at the Victoria University of Manchester from the Small-Scale Experimental Machine (SSEM) or "Baby" (operational in June 1948). It was also called the Manchester Automatic Digital Machine, or MADM.

Some Early Computers The UNIVAC I (1951): The UNIVAC I (UNIVersal Automatic Computer I) was the first commercial computer produced in the United States. It was designed principally by J. Presper Eckert and John Mauchly, the inventors of the ENIAC. Design work was started by their company, Eckert–Mauchly Computer Corporation, and was completed after the company had been acquired by Remington Rand (which later became part of Sperry, now Unisys). In the years before successor models of the UNIVAC I appeared, the machine was simply known as "theUNIVAC".

COMPUTER GENERATIONS “Generation” in computer talk is a step in technology. It provides a framework for the growth of computer industry Originally it was used to distinguish between various hardware technologies, but now it has been extended to include both hardware and software Till today, there are five computer generations

COMPUTER GENERATIONS

COMPUTER GENERATIONS

COMPUTER GENERATIONS

COMPUTER GENERATIONS

COMPUTER GENERATIONS

DRUM PRINTERS Line printers that print one line at a time Have a solid cylindrical drum with characters embossed on its surface in the form of circular bands. Set of hammers mounted in front of the drum in such a manner that an inked ribbon and paper can be placed between the hammers and the drum Can only print a pre-defined set of characters in a predefined style that is embossed on the drum Impact printers and usually monochrome Typical speeds are in the range of 300 to 2000 lines per minute

DRUM PRINTERS

CHAIN/ BAND PRINTERS Line printers that print one line at a time Consist of a metallic chain/band on which all characters of the character set supported by the printer are embossed Also have a set of hammers mounted in front of the chain/band in such a manner that an inked ribbon and paper can be placed between the hammers and the chain/band

CHAIN/ BAND PRINTERS Can only print pre-defined sets of characters that are embossed on the chain/band used with the printer Cannot print any shape of characters, different sizes of print, and graphics such as charts and graphs Are impact printers and can be used for generating multiple copies by using carbon paper or its equivalent Are usually monochrome Typical speeds are in the range of 400 to 3000 lines per minute

LEASER PRINTER Page printers that print one page at a time Consist of a laser beam source, a multi-sided mirror, a photoconductive drum and toner (tiny particles of oppositely charged ink) To print a page, the laser beam is focused on the electro statically charged drum by the spinning multi-sided mirror Toner sticks to the drum in the places the laser beam has charged the drum’s surface. Toner is then permanently fused on the paper with heat and pressure to generate the printer output Laser printers produce very high quality output having resolutions in the range of 600 to 1200 dpi

LEASER PRINTER Can print many special characters, different sizes of print, and graphics such as charts and graphs Are non-impact printers Most laser printers are monochrome, but color laser printers are also available Low speed laser printers can print 4 to 12 pages per minute. Very high-speed laser printers can print 500 to 1000 pages per minute More expensive than other printers

LEASER PRINTER

PLOTTERS Plotters are an ideal output device for architects, engineers, city planners, and others who need to routinely generate high-precision, hard-copy graphic output of widely varying sizes Two commonly used types of plotters are: – Drum plotter, in which the paper on which the design has to be made is placed over a drum that can rotate in both clockwise and anti-clockwise directions – Flatbed plotter, in which the paper on which the design has to be made is spread and fixed over a rectangular flatbed table

DRUM PLOTTER

FLATBET PLOTTER