Assignment 4: Drum Memory, Printers, RAM and Display Terminals

Drum Memory, Printers, RAM and Display Terminals

Magnetic Drum

It was an early form of primary computer memory. For many machines, a drum formed the main working memory of the machine, with data and programs being loaded on to or off the drum using media such as paper tape or punch cards. Magnetic Drums have become more than obsolete today and it has been replaced by the semiconductor memory.

A drum is a large metal cylinder that is coated on the outside surface with a ferromagnetic recording material akin to the hard disk but with rotating drums instead od rotating platters. A row of read-write heads runs along the long axis of the drum, one for each track.

Printers and its types

It is a device to produce the hard copy of the documents, images etc stored in the digital form ie the soft copy.

Historically, Charles Babbage’s printer for hitting characters on the metal plate is regarded as the first printer.

Printers are generally connected to the computer via the parallel LPT port. But these days, the Universal Serial Bus (USB) are rather replacing these ports as the major printer connecting port.

On the basis of printing technology used, printers are generally classified into two types; the impact printers and the non-impact printers. Impact printer use physical hitting on the paper with the typefaces while non-impact printers do not have any physical contact with the paper (The print head of the impact printers make physical contact with the paper while that of non impact do not).

#Some common printers classified

Dot matrix printers: These printers use the matrix of dots on their print head to hit the ink ribbon over the paper to form an image of text. Hence they are impact printers. These printers are not in much use these days because they are slow and noisy. These printers can be seen in use where economical or carbon copy prints are required.

Line Printer: Line printer prints one complete line at a time. It is used for heavy printing applications and can be operated continuously for long time. It has a speed of 300 lpm to 2500 lpm (ie. lines per minute). They are also impact printers.

Drum Printer: A drum printer consists a cylindrical drum which is embossed with characters. It also consists of hammer and carbon ribbon. The drum rotates at a high speed which is striked bt hte hammer to get hard output on the paper. It prints the characters of same font only as the print cylinder is fixed. They are also impact printers.

Laser printers:
These printers can print at a very high speed. They use laser technology together with toner (a type of printer ink) and a light sensitive print drum to produce images or texts on the paper. Obviously, they are non-impact printers.

Inkjet printers: They operate by propelling tying droplet of liquid ink over the paper to reproduce texts or images. These printers have good printing speed and are relatively cheap (but they are not economical because of the high price of the ink and less pages printed per refill kit)


Most modern day printer can print both text and image but printers like Line printer, drum printers can print only characters.

Again, some printers which can print images can only print monochrome images while others can print multi-colour images or texts.

Differences between magnetic and optical storage

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Differences between SRAM and DRAM

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Difference Between LCD, LED And CRT

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Assignment 3: The impact of Computers on the Society

The impact of Computers on the Society

Assignment 3

Computers have become omnipresent these days. From the benevolent researchers to the evil criminals, computers are used by almost everyone associated with almost every field. Computers have become so indispensable that the world will cease to function without it functioning properly. The computers power the world economy, the entertainment industry, communication system, transport system and almost everything that we can think of. Besides, computers are a common house hold item these days. From listening to music to playing games to inventory management, computers are being used at home. It is clear that computers have penetrated a lot may aspects of human society and culture and our everyday life, its impact on us and our society is remarkable.

1. Computers have increased out productivity in every field. Tasks that would require days to complete can be done in no time these days. That means we can do more work in less time.

2. Computers have revolutionized world communication. The use of emails, IMs, IRCs, Blogs, Forums and all have changed the way we used to communicate.

3. Computers have become our day to habit. We use it for entertainment purpose, education purpose, inventory management all many other purpose. This have made our work easier and our studies more effective but we no more go outside to play games or interact with out neighbors much.

4. With the advent of Internet, most of our interactions with the service providers like Banks, ISPs, Mobile service providers, schools, campuses have gone online. That makes the transactions and information sharing effective and fast but it also exposes us to different computer related crimes like identity theft, password theft and others.

5. With computers changing its status from amenity item to inevitable household item, it has created pressure to the economically backwarded people to get one in their house as well. This can give rise to different malpractices in the society like theft and abuse in the name of providing loans.

6. Evolution of computers is a very rapid process. New technology comes forth every month. It is very difficult to keep up with these changes.

7. Activities like identity fraud, human proxing, cheating, and other illegal and anti-social activities have gone up due to use of computers.

8. Computers are rendering peoples physically vegetative. News like death due to over indulgence with computer games and internet are no more rare.

9. Personal abuse, insult, racketeering and other malpractices have increased.


Having said all this, it can be concluded that computer are indispensable for us. But to keep the negative impacts at bay or to minimize them, we have to use computers more sensibly and promote ethical use of computers.

Assignment 2, part 2: Generation of Computers

Generations of computers

Assignment 2, part 2

Please click on the link to view the image http://tinyurl.com/yvbreq

Assignment 2, Part 1: The History of Computer in Nepal

The History of Computer in Nepal

Assignment 2, part 1

Nepal didn't play any role in the development of computer technology. Obviously, computers in Nepal were introduced very late. While the people of most of the countries had begun to take computer as a means of household must-have, most of us hadn't even heard of the name 'Computer'. To cut the long story short, here I list the chronologically arranged events that marked the arrival of computers in Nepal and its increase in presence in the country.

1. The Main Frame IBM-1401 computer was installed and operated in 1971, in the National Computer Center (NCC) at Kathmandu for the National population census. This event marked the advent of Electronic Data Processing Technology in Nepal. NCC was established with the purpose of giving computer related service to government bodies, developing computer manpower and enhancing computer consciousness.

2. Later on NCC used ICL-2950/10 Main Frame computer, a DG Mini-computer, a Prime Mini-computer.

3. Inspired by the success of NCC's activities and to fulfill the people's quest for new knowledge and skills, now a day there are more than 300 private Computer training institutes. These institutes, both big and small have played a significant role in promoting IT awareness in the country. Besides conducting training programs, many of these private companies offer Consultancy services, Software Packages and Hardware maintenance as well as computer
assembly. IT solution provider companies are also slowly coming up in the capital Kathmandu.

4. In the education sector also IT subject have been introduced from the primary level to higher
secondary level. These days, there are many colleges running graduate level academic IT courses. Personal Computer is fast becoming an essential household item in the affluent families of the country.

5. Internet technology has also been introduced to the country. Modern Telecommunication Services, which are the backbone of IT, are recently developed. In Nepal first Telephone Exchange was established in 1960. Telephone Services are provided only by Nepal Telecommunication Corporation (NTC), a government undertaking. There is more than 7 private Internet Service Provider (ISP) in the Kathmandu valley, besides NTC. Government has also issued license for Cellular & WLL networks to Private parties.

6. These days many teenagers are hooked to Internet Chat and mail services. Internet cafes have sprouted like mushrooms in the country. Tourists visiting the country are also finding it very handy and useful. Web designing courses are in very much demand. Internet is fast becoming a household necessity.

7. With all these activities, and infrastructure development, the information technology situation in Nepal is heading towards rapid development. Qualified HR well versed in IT is rapidly growing in the country. The IT related works done in the overseas country can be done here at the one fourth of that cost, since HR costs as well as infrastructure costs here are very low.

8. Nepali IT companies are trying to get a breakthrough in the global market, which they are finding it extremely difficult to get access and directly penetrate. IT is the main hope for a landlocked mountainous country like Nepal. The day, Nepal will show its presence in the IT map of the globe, will be the brightest day in the history of the country.

Assignment 1: The History of Computing

The Evolution of Computing:
From Abacus to multicore processors

Assignment 1

The Beginning

Computing has always been an important aspect of human life. We computed the number of sheep in our herds and now we need to perform complex computations so as to project a satellite on its orbit. Back then, our ancestors used pebbles, scratches, knots or other counting aids to represent the cardinality of object they posses. Then came the numbers, then the ‘zero’. The invention of ‘zero’ was one of the major advances in the science of computing. The number set was complete. But still, human used primitive counting aids for calculations. The number of people had increased by then; there were more sheep to be counted and more people to be dealt to. The degree of computational need had risen exponentially. People needed something that can improve the efficiency and accuracy of their calculations. As every need in nurtured by the urge to have it, the very first device calculating device, the Abacus was born. Thus begin the era of aided computation.

The Chronology of Computing Devices

The Early Calculating Devices

[Abacus]
-It was the an early aid for mathematical calculations.
-Instead of performing actual calculations, it aided the memory of the human performing the calculation.
-Abacus basically consisted of a wooden frame with strings and beads attached to it. But there are many variations of Abacus as per their origin.
-A skilled Abacus user can perform addition and subtraction as fast as a normal person with a calculator can.
-Abacus are still used in some schools to aid the learning of numeral system and arithmetics.

Fig: Abacus

[Napier’s Bone]
-Invented around 1617 by a Scottish mathematician John Napier.
-It worked on the principal of multiplication through repetitive addition and division through repetitive subtraction.
-The device was powerful enough to perform multiplication, division and calculations regarding the square root.

Fig: Napier's Bone

[Slide rule]

-It was a mechanical analog device, consisting of at least two finely divided scales (rules), most often a fixed outer pair and a movable inner one, with a sliding window.

-The slide rule was used primarily for multiplication and division, and also for scientific functions such as roots, logs and trig.
-Slide rule was in use until very recently pocket calculator replaced them.

Fig: Slide Rule

[Pascaline]
-Invented by Blaise Pascal in 1642 to aid his father in his work of tax calculations.
-It was a machine based on decimal number system. It was of the size of a shoe box and consisted of dials and a display ports. The dials were used for number entry and the display ports to view the result.
-The functionality of Pascaline was dependent on gears and wheels so it broke down often and was hard to build.

Fig: Pascaline

[Stepped Reckoner]
-Invented by Gottfried von Leibniz in the 1960s.
-Unlike Pascaline which could only add and subtract, Stepped Reckoner was able to carry out multiplication and division.
-Stepped Reckoner was based on decimal number system as well.

[Jacquard's Loom]
-Invent at around 1801 by Joseph Marie Jacquard, a Frenchman.
-It was not a calculating device but it gave the idea of discrete computing through the use of punched card to control the pattern woven in his loom.

Fig: Jacquard Card

[Difference Engine]
-By 1822, English mathematician Charles Babbage proposed a steam driven calculating machine the size of a room, which he called the Difference Engine. It was based on “many long calculations, especially those needed to make mathematical tables, were really a series of predictable actions that were constantly repeated and thus these calculations can be performed automatically”.
-The machine was based on wheels, cogs and dials. So it had a high error repeat frequency.
-While Babbage was working on improving his Differential Engine, he got interested in another new better idea and left to work on Differential Engine

Fig: A module of Difference Engine

[The Analytical Engine; the precursor of modern computers]
-The Analytical Engine was that better idea for which Babbage had left working on Difference Engine.
-The Analytical Engine was the mirror of the operating methodology of modern computers. The Analytical Engine was supposed to have an input unit; input would be provided through the use of Punched Cards, an output unit; in the form of printers and bells, the processing unit; in the form of mills made up of wheels and gears and cogs, and the storage unit. The input unit, output unit, processing unit and the storage unit comprises the architect of modern computers.
-The machine was supposed to be powered my stem engines and consisted of many mechanical parts. So it would occupy a large space.
-The Analytical Engine was a computer and not merely a calculator because it had the ability to be programmed. Punched cards were to be used to program Analytical Engine.
-Babbage had discussed the idea of Analytical Engine with Ada Byron (she would later become the Countess Lady Lovelace by marriage). She was fascinated by the idea and began to learn about the engine through meetings and letters from Babbage. She soon began to write programs for the incomplete machine and thus is regarded as the first programmer.
-The Analytical Engine was a grand idea but because of financial, political, and legal issues, the engine was never actually built. Nevertheless, its laid the foundation for the architect of modern computers. And because of this Charles Babbage is regarded as the father of modern computers.

Fig: Charles Babbage

[Hollerith Desk]
-Herman Hollerith designed and developed Hollerith Desk (aka Hollerith Calculating Machine) for use in the 1890 census of USA.
-Hollerith had ported the punched card technology used in the Jacquard Loom into his calculating machine for computational purpose.
-Hollerith built a company named Tabulating Machine Companyn which eventually became International Business Machine (IBM) after some buy outs.

Fig: Hollerith Desk

True Computers

The world had seen a lot of computing devices but there still was the need of true computers that could be programmed. And the World Wars fuelled the need of developing such system even more. At the time of war, error in computation of trajectory, velocity of wind, air drag, effect of temperature, relative position of enemy base, and other factors would mean getting defeated. So every country wanted better computers with better processing and storage and programming capabilities. And The United States of America was ahead in the race.

[Mark I]
-It was built as a partnership between IBM and Harvard university in 1944. It was devised by Howard H. Aiken.
-It was the first programmable digital computer but it was not purely electronic.
-The machine was enormous with 5 tons weight, incorporated 500 miles of wire, was 8 feet tall and 51 feet long, and had a 50 ft rotating shaft running its length, turned by a 5 horsepower electric motor.
-The machine was slow as compared to modern computers and generated a lot of heat. It required a massive heat sink facility. It would broke down too often and had big maintenance problem. It was difficult to program.

Fig: Mark I

[ENIAC]
-It was the first electronic, digital computer devised by John Mauchly and J. Presper Eckert.
-ENICA too was a massive system. It contained 17,468 vacuum tubes, 7,200 crystal diodes, 1,500 relays, 70,000 resistors, 10,000 capacitors and around 5 million hand-soldered joints. It weighed 30 short tons (27 t), was roughly 8 feet (2.4 m) by 3 feet (0.9 m) by 100 feet (30 m), took up 1800 square feet (167 m²), and consumed 150 kW of power. Input was possible from an IBM card reader, while an IBM card punch was used for output. These cards could be used to produce printed output offline using an IBM accounting machine.
-ENIAC was based on Decimal system.
-Being huge and built on vacuum tubes, it too generated a lot of heat and was unreliable.

Fig: ENIAC

[EDVAC]
-It was also devised by John Mauchly and J. Presper Eckert.
-This was also a massive system. The computer had almost 6,000 vacuum tubes and 12,000 diodes, and consumed 56 kW of power. It covered 490 ft² (45.5 m²) of floor space and weighed 17,300 lb (7,850 kg).
-It was the first computer to use the stored program concept put forward by John Von Neumann-Unlike any computer of that time, EDVAC was based to Binary number system.

Fig: EDVAC

ABC, EDSAC, UNIVAC, Zeus 1, Zeus 2 etc were also some of the notable computers of that time.
All of these computers were huge and bulky. They generated a lot of heat and were hard to maintain.

A prespective on computing evolution

Now that people had seen computers and felt its effect on their day to day life, they need one in their home as well. As the technology got better and better, devices like transistor and IC (Integrated Circuit) were invented. A single transistor could do the switching job of hundreds of vacuum tubes and the IC could the hundreds of transistor alone. An IC is basically a fabrication of different electronic devices such as transistors, inductors, resistors in a single silicon chip. Because of the ICs, computers were able to fit inside a single room or to say on a small reading table. Different processor fabrication technology like VLSI (Very Large Scale Integration) and ULSI (Ultra LSI) reduced the size of computers even more and made them able to fit inside our pocket.

Rapid progresses are being made in the field of processor design and fabrication. Parallel processing is the buzzword. The common trend of the market is Dual Core processors; processors with two computing core. Intel had demonstrated its prototype 80 core processor. Advances are being made in the field of Artificial Intelligence. The Moore’s law of doubling the processor speed every 18 months has long been outsmarted and now we have reached near saturation of processing speed that can be offered by the present technology. So, again there is going to be dire need of new computer design and system fabrication methods. Therefore new ways are being sought out. Optical chips, quantum computing and other seeming absurd physics are coming into play. Researches are being made in every possible field which can help in advancement of computational capacity. These days, we have so much computational power at our dispatch that the calculations that would take months to compute could take only few microseconds. But still, it is not sufficient. There is ever increasing demand of computing power.

Today we need computers to route the traffic of the internet, we need then to plan our mission to Mars or moon or other planets even, and we need computers for deployment massive and complex encryption methodologies. They all demand a huge processing power. We flamed ENIAC and EDSAC for occupying a big room but still today our computers fills an entire room, be it the computers in the NASA control centre or on the US department of Defense. The need of now and then were the same but the scale was different. So, there still exists the need for the search of even higher computing power. Human demands are ever increasing and so should the computing power be.

So, we have the history of evolution of computing in a nutshell. From the Abacus to the processors of the futures, the all were the manifestations of human need for computing. Early people thought Abacus was getting short of their demand and the people of today think multicore processors are getting short of demand. Human need of computation is ever increasing and as we replaced abacus, our microprocessors will also be replaced by…who knows!!!

About this Blog

Hello teacher.

As you have asked us to submit all our assignments in soft copy, I just thought of posting all the assignments in a blog so that everything gets a bit organised. That will make you reviewing you assignments pretty easy and i too won't have the hassle of attaching .doc or .pdf files on the email, I can work directly on the blog. Besides, posting assignments on the blog will facilitate sharing my work among my friends. I will be sending you the link to the assignments or you can just visit the URL http://assignments-sulabh.blogspot.com/

Regards,
Sulabh Bista
CE 1st year, 1st sem