MCA1010- FUNDAMENTALS OF COMPUTER AND IT
Q1.) Compare first generation and second generation computers.
Ans.) The First Generation Computers:
The first generation computers were developed during 1943-1958. It used vacuum tubes as the active electronic components & was therefore very large. However some of the features are as follows-
1. They were extremely large & occupied a very large space.
2. They used vacuum tubes as memory device.
3. They were very expensive & consumed a lot of electrical power.
4. The operating speed was measured in milliseconds.
5. These computers had low level of accuracy & reliability.
6. Storage capacity was too small only 1 to 4kb.
7. They used machine level programming language.
The examples are - UNIVAC, ENIAC, EDSAC, & EDVAC
The Second Generation Computers:
The second generation computers were developed during 1959-1965. The invention of the transistor by three scientists of Bell Telephone Laboratories in 1947 greatly changed the development of computers. However some of the features are as follows-
1. These computers used transistor.
2. They were smaller, faster & cheaper than first generation of computers.
3. They consumed less electrical power than first generation.
4. The operating speed was measured in microseconds.
5. They were more reliable & accurate than the first generation computers.
6. They could understand high level language such as COBOL.
7. Magnetic tapes were used as secondary storage media.
The examples are – IBM 1620, IBM 1401, & CDC 3600.
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Q2.) Differentiate between integrated Circuits and microprocessors.
Ans.) Integrated Circuits:
The development of the integrated circuit was the hallmark of the third generation of computers. A non-metallic chemical element in the carbon family of elements Silicon – atomic symbol “Si” is the second most abundant element in the earth’s crust, surpassed only by oxygen. Silicon does not happen uncombined in nature. Sand & almost all rocks contain silicon combined with oxygen, forming silica. When silicon combines with other elements, such as iron, aluminum or potassium, a silicate is formed.
A chip is a small piece of semi conducting material (usually silicon) on which an integrated circuit is embedded. A typical chip is less than ¼ - square inches & can contain millions of electronic components (transistors).
Semiconductor is a material that is neither a good conductor of electricity (like copper) nor a good insulator (like rubber). The most common semiconductor materials are silicon & germanium. These materials are then doped to create an excess or lack of electrons.
Computer chips, both for CPU & memory, are composed of semiconductor materials. Semiconductors make it possible to miniaturize electronic components, such as transistors. Not only does miniaturization mean that the components take up less space, it also means that they are faster & require less energy.
Microprocessors:
The microprocessor brought the fourth generation of computers, as thousands of integrated circuits we rebuilt onto a single silicon chip & this will contains a Central Processing Unit. In the world of personal computers, the terms microprocessor & CPU are used interchangeably. At the heart of all personal computers & most workstations sits a microprocessor.
The integration of a whole CPU onto a single chip or on a few chips greatly reduced the cost of processing power. The integrated circuit processor was produced in large numbers by highly automated processes, so unit cost was low.
Single-chip processors increase reliability as there are many fewer electrical connections to fail. As microprocessor designs get faster, the cost of manufacturing a chip (with smaller components built on a semiconductor chip the same size) generally stays the same.
Microprocessors also control the logic of almost all digital devices, from clock radios to fuel-injection systems for automobiles. The internal arrangement of a microprocessor varies depending on the age of the design & the intended purposes of the processor.
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Q3.) What is the significance of Processor mode? Explain three types of processor modes.
Ans.) Processor modes refer to the various ways that the processor creates an operating environment for itself. Specifically, the processor mode controls how the processor sees & manages the system memory & the tasks that use it. There are three different modes of operation that resulted from the evolution of the PC from its humble beginnings with the Intel 8088 chip.
The concepts of processor modes in generic term, mode is a way that creates a system for itself for its processor creation & operations. Processor mode is responsible for managing & controlling the system memory & its use. Processor modes refer to the various operating environments & affect the instructions & capabilities of the chip. The processor mode controls how the processor sees & manages the system memory & the tasks that use it.
Processor modes are classified into three types as:
1. Real Mode: This mode operates CPU in a limited environment. The real mode has the advantage of accessing speed. It is compatible with Intel 8088 chip. All processors can support real mode. Computers normally boot up in real mode or DOS mode.
2. Protected Mode: This mode used in modern multitasking operating systems was first implemented in 80826. Protected Mode has several advantages. It offers faster access to memory
a. It supports multitasking facility that manages the operating.
b. System in the execution of many programs at a time.
c. There is no limit for accessing the memory.
d. It allows the computers to use additional memory whenever
e. Needed along with the support of virtual memory.
3. Virtual Real Mode: This mode of operation is the enhancement of protected mode. Protected mode is used to run graphical multitasking OS like windows. If you want to run DOS program in the windows system then you would have to use the virtual real mode. This is because the necessity of running DOS program on real mode & not in protected mode has given rise to the virtual real mode. This mode will simulate the real mode to start in the protected mode & help in running DOS programs in windows. The virtual machine will have separate address space dedicated to it, which helps in invoking this feature of operating virtual real mode machines.
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Q4.) Explain the features of a mouse and a track ball
Ans.) Mouse:
It is most common pointing input device. The data is entered by pointing the mouse to a location on the computer screen. The mouse may also be used to position the cursor on screen, move an object by dragging, or select an object by clicking. The key benefit of using a mouse is that the cursor moves with the mouse. So, the cursor can be positioned at any location on the screen by simply moving the mouse. Moreover, it provides an easy way to select & choose commands from menus, dialog boxes, icons, etc. Mouse is used extensively, while working with graphics elements such as line, curve, shapes, etc.
Trackball:
Trackball is a device that is a variant of the mouse but has the functionality of mouse. It is easy to use & takes less space than a mouse. Trackball is generally built in laptops since there is no space for the mouse to move on the lap. Trackballs come in various sizes- small & big.
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Q5.) What is data communication? Explain different Data Transmission methods.
Ans.) Data communication is the transfer of data or information between a source & a receiver, the source transmits the data & the receiver receives it. The distance over which data moves within a single IC chip, to as much as several feet along the backplane of the main circuit board. Over such small distances, digital data may be transmitted as direct, two-level electrical signals over simple copper conductors. Except for the fastest computers, circuit designers are not very concerned about the shape of the conductor or the analog characteristics of signal transmission.
Data Transmission Methods:
Transmission media is the physical path between the transmitter & receiver. It can be guided or unguided.
Guided & unguided transmission medium
Guided media provides a guided (by a solid medium) path for propagation of signals such as twisted pairs, coaxial cables, optical fibers etc. Unguided media employ an antenna for transmitting through air, vacuum or water. This form of transmission is referred to as wireless transmission. For e.g. Broadcast radio, satellite etc.
Selection of transmission Media depends on the characteristics & quality of data transmission which are in turn determined by characteristics of the medium & signal. For guided media the medium itself in determining the limitations of transmission. For Unguided media Bandwidth (BW) width of the signal produced at the transmitting antenna is more important than characteristics of the transmission characteristics.
Factors used to determine data rate & distance are:
· Bandwidth (BW): Greater the BW of the signal, higher the data rate that can be achieved.
· Transmission impairment: These limit the distance. Twisted pair suffers more impairment than coaxial cable which in turn suffers more than optical fiber.
· Interference: Overlapping frequency bands can distort/wipeout a signal. It is of more concern for unguided media than guided.
For guided it can be caused due to nearby cables. Proper shielding of cables can minimize this problem.
· Number of receivers: Point to point links is used or a shared link is used with multiple attachments.
In a shared link, each attachment introduces some attenuation & distortion on the line limiting the distance and/or data rate.
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Q6.) What is an IP address? Describe the classes of IP addresses.
Ans.) IP addresses are represented by a 32-bit unsigned binary value. It is usually expressed in a dotted decimal format. For example, 9.167.5.8 is a valid IP address. The numeric form is used by IP software. The mapping between the IP address and an easier-to-read symbolic name, for example, myhost.ibm.com, is done by the Domain Name System (DNS).
The classes of IP addresses:
Class A addresses: These addresses use 7 bits for the <network> & 24 bits for the <host> portion of the IP address. This allows for 27 – 2 (126) networks each with 224 – 2 (16777214) hosts – a total of more than 2 billion addresses.
Class B addresses: These addresses use 14 bits for the <network> & 16 bits for the <host> portion of the IP address. This allows for 224 – 2 (16382) networks each with 216 – 2 (65534) hosts – a total of more than 1 billion addresses.
Class C addresses: These addresses use 21 bits for the <network> & 8 bits for the <host> portion of the IP address. That allows for 221 – 2 (2097150) networks each with 28 – 2 (254) hosts – a total of more than half a billion addresses.
Class D addresses: These addresses are reserved for multi-casting (a sort of broadcasting, but in a limited area, & only to hosts using the same Class D address).
Class E addresses: These addresses are reserved for future or experimental use.
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