Repulsion Type MI instrument

Repulsion principle is very commonly used in MI instruments.The operation of such an instruments depends upon the mutual repulsion of two vanes of ferromagnetic material magnetize by a current-carrying coil.Fig shows a typical form of a repulsion-type MI instrument.It consists of a fixed coil C in which are placed two vanes A and B.Vane A is fixed in space while vane B is attached to a spindle S carrying a pointer PR.When the current to be measured is passed though the coil a magnetic field is produced.This magnetic field magnetizes the two vanes with the same polarity.Hence the vanes repel each other,with the result that the pointer is deflected.

The deflection depends on the product of the pole strengths of A and B.It is therefore proportional to the square of the magnetic field strength.Since both A and B are magnetized by the same coil current,the deflection is proportional to the square of the current.It is assumed that A and B are not magnetically saturated.Since the polarity of both the vanes reverse simultaneously,the deflection of the pointer is in the same direction for both a.c. and d.c.If a.c. is passed through the coil the deflecting torque is proportional to the mean value of the square of the current.The scale is calibrated to indicate the square root of this value for d.c. and the r.m.s. value for a.c.   

Attraction type MI instrument

The attraction type of MI instrument depends on the attraction of an iron vane into a coil carrying current to be measured. fig 1 shows a MI instruments of attraction type.A soft iron vane IV is attached to the moving system.when the current to be measured is passed through the coil C,a magnetic field is produced.This field attracts the eccentrically mounted vane towards it.Thus,the pointer PR,which is attached to the spindle S of the moving system is deflected.The pointer moves over a calibrated scale.

The control torque is provided by two hair springs S1 and S2 in the same way as for a PMMC instrument;but in such instruments springs are not used to carry any current.The damping torque is provided by the movement of a thin vane V in a closed sector-shaped box B.

If the current in the fixed coil is reversed,the field produced by it reverses,so the polarity induced on the vane reverses.Thus,whatever be the direction of current in the coil,the vane is always magnetized in such a way that it attracted into coil.The force of attraction is proportional to the square of the current,provided that the moving iron vane is not magnetically saturated.Hence,such instruments can be used both for direct and alternating currents.Attraction-type MI instruments are not commonly used in practice. 

System interconnection(Lines)

Two or more generating stations are interconnected by tie lines.Interconnection of generating stations has the following important advantages:

1.It enables the mutual transfer of energy from surplus zone to deficit zone economically.

2.Lesser overall installed capacity to meet the peak demand.

3.Lesser standby reserve generating capacity.

4.The size of the biggest unit is not related to the peak load of an individual system but it related to the peak load of the interconnected system.Thus,fewer but larger machines of greater efficiency are to be installed.

5.It permits the generation of energy at the most efficient and cheapest stations at every time.

6.It reduces the capital cost,operating cost of energy generated.

7.If there is a major breakdown of a generating system unit in an interconnected system there is no interruption of power supply.Similarly,when a machine is taken out of service for its scheduled maintenance and inspection,the continuity of supply is maintained.In other words,the planning of plant outages for maintenance and repair work is facilitated.

Thus,interconnection provides the best use of power resources and ensure greater security of supply.It enables overall economic generation by optimum use of high capacity economical generating plants.Interconnection between network is done either by  HVAC links or HVDC links.

An interconnected power system covering a major portion of a county's territory(or state) is called a grid.The different grids may be interconnected through transmission lines(called tie lines) to form a regional gird.When the different regional grids are interconnected,they form a national grid.   

Electric Power Systems

An electric power system has the following basic functions:

1.Generation of electrical energy economically with minimum ecological disturbance.

2.Transfer of this energy to consumers with maximum efficiency and high reliability at practically constant voltage and constant frequency.

Electric power generation system

Large amount of power is generated at the generating stations.The present trend is to install bigger size of alternators to generate large amount of power to cater the required increasing demand.The site of the power station depends upon the type of power station.The new thermal stations are being constructed at pit heads (near the coal mines) because of the higher cost of transportation of coal.Hydro-power station sites are governed by the availability of water resources.The nuclear plants are also situated remote from the centers of consumption due to safety reasons. Thus,the difficulty of getting power station sited near the consuming centers makes it inevitable to transfer    bulk of electrical energy through longer distances.Long-distance,bulk power transfer is only possible by high voltage transmission systems.Extra high voltage (EHV) and ultra high voltage (UHV) transmission systems have been developed in most of the countries for transporting energy from remote power stations.By EHV is meant the voltage above 220 kV. The voltages above 760kV are called ultra high voltages (UHV). 

picture of power station(nuclear power plant

Classification of Lines(electrically or physically)

Lines may be classified either electrically or physically.

Electrical Classification

1.Direct Current (DC) systems

(a) DC 2-wire ,1-wire earthed

(b) DC 1-wire ,earth return

(c) DC 2-wire, mid-point earthed

(d) DC 3-wire.

2.Alternating Current (AC) system 

(a) Single-phase,2-wire,1-wire earthed.

(b) Single-phase,1-wire,earth return.

(c) Single-phase,2-wire,mid-point earthed.

(d) Single-phase,3-wire

(e) Two-phase ,3-wire

(f) Two-phase,4-wire

(g) Three-phase,3-wire

(h) Three-phase,4-wire

All these system are used in practice. Every system has got its own field of application.The line economics varies with the individual  system.Direct current 2-wire,mid-point earthed system is used for transmitting large amounts of power over load distances.

Single-phase a.c.system is rarely used for transmitting purposes. Three-phase 3-wire a.c.system finds its greatest use for transmission and primary distribution.For secondary distribution work three-phase,4-wire system is common.The industrial and other big loads are supplied by three-phase,4-wire system.The domestic and other small load consumers are supplied with single-phase power obtained from the individual phases of a three-phase supply.

Physical Classification

The other criterion of classification  of lines is their physical configuration.The lines may be overhead,underground or underwater.Again,overhead lines may either have bare conductors or insulated conductors.

Most of the high voltage and extra high voltage lines have bare conductors since these are most economical.The conductors on overhead lines are sometimes insulated for safety or other considerations.The insulated aerial cabled although costlier than the bare conductors are far cheaper than the underground cables. They  are used in densely populated urban areas at relatively low voltages or for rural distribution work at medium voltages.

For long river or sea crossing,it is not possible to erect overhead lines due to their longer spans.In such cases the need of underwater cables becomes inevitable.such cables are very costly to manufacture and install.  

LOCAL AREA NETWORK(LAN) & WIDE AREA NETWORK(WAN)

LAN:
In an industry,commercial organization or an office which has several computers in a building or a campus,need may arise to transmit data between computers.in such a situation a high-speed interconnecting network called local area network(LAN) is needed to interconnect the computers so that they can communicate with each other.There are various ways for interconnecting computers such as star,common-bus,ring type LAN,and so on.In a star type LAN there is a central controller that  coordinates all communication between computers on the LAN.The common-bus type LAN also known as Ethernet,dose not have any central controller.Rather,the control of the bus is spread among all the computers connected to the common-bus.The common-bus is spread among all the computers connected to the common-bus.The common-bus is simply a wire usually a co-axial cable to which any number of computers can be easily connected.Any computer can take over the bus to transmit data.Two computers are not allowed to transmit data at the same time.Also,in the ring type LAN,the control is distributed among all of the computers on the network.A binary  code called token is passed around the ring from workstation.All workstation are linked to form a continuous loop.A computer which wants to transmit data must possess the token.It takes the token form the bus,to prevent any other computer from transmitting.After the transmission is completed,it puts the token on the ring so that another computer which has to transmit data can receive it.
LANs are classified according to their data transfer speed,as:high speed,medium-speed and low-speed LANs. In high-speed lANs data are transmitted at the rate of 20 millon bits per second (MBps).such LANs are designed  to link mainframe computers.In medium-speed LANs data are transmitted at the rate of 3-20 Mbps.such LANs are suitable to link smaller mainframes,minis and PCs.Example of a medium-speed LAN is Ethernet.Its speed is 10 Mbps.Low-speed LANs transmitted data at 3 Mbps.They are suitable to link PCs and other workstations.

WAN: when computers/terminals are spread over a wide area,they can e connected through public or private communication system.This type of network is called wide area network(WAN).Internet is also a kind of WAN. 

example of LAN

BUSES (in computer)

Memory and I/O devices are connected to the CPU through a group of lines called a bus.These lines are meant to carry information.These are three types of buses:address bus,data us and control bus.An address bus carries the address of a memory location or an I/O devices that the CPU wants to access.The address bus is unidirectional.The data and control buses are bidirectional because the data can flow in either direction;from CPU to memory (or I/O device) or from memory (or I/O devices) to the CPU.Examples of control signals are:

fig1 shows the schematic diagram of I/O or memory connection to CPU.

Different types of bus architectures such as ISA,PCI,AGP,USB etc.

CPU

The CPU is the brain of a computer.Its primary function is to execute programs.Beside executing programs,the CPU also controls the operation of all other components such as memory,input and output devices.Under its control,programs and data are stored in the memory and displayed in the CRT screen or printed on the printer.

The CPU of a small computer is a microprocessor. Fig1 shows the schematic diagram of a microcomputer.The CPU of a large computer contains a number of microprocessors and other ICs on one or more circuit boards.Each microprocessor in a large CPU performs a specific task.

Fig.2 shows the schematic diagram of a CPU or microprocessor.

The major sections of a CPU are:

(i)Arithmetic and Logic Unit (ALU)

The function of an ALU is to perform arithmetic and logic operations such as addition,subtraction,multiplication,and division; AND,OR,NOT(complement) and EXCLUSIVE OR operations.It also performs increment,decrements,shift and clear operations.It also performs increment,decrements,shift and clear operations. 

(ii)Timing and control Unit 

The timing and control unit generates timing and control signals necessary for the execution of instructions. It provides status,control and timing signals necessary for the operation of other parts of the CPU,memory and I/O devices.It controls the entire operation of a computer.It is actually the control section of the CPU,which acts as the brain of a computer.

(iii)Accumulator,General and Special Purpose Registers.

cooler fan of cpu

CPU

The accumulator is a register which holds one of the operands prior to the execution of an instruction and receives result of the most arithmetic and logical operation.It is the most frequently used register.some CPUs contain a single accumulator,other contain several accumulators.General purpose registers store data and intermediate results during the execution of a program.They are accessible to programmers through instructions if they are working in an assembly language.Special purpose registers are not accessible to users.They are used by the computer for different purpose duing program execution.Examples of special purpose register are: program counter,stack pointer,ondex registers,instruction register,etc.

what is servers ?

Servers:
These are powerful computers.A number of PCs and terminals can be connected to a server.servers are provided with large disk and RAM capacity.In a low-end server only one microprocessor is used to act as a CPU.on the other hand in a high-end server,a number of microprocessor are provided in the CPU.Microprocessor in a multiprocessor CPU operate in parallel.

Server Digitization 

The user working on a PC connected to a server,makes simple computation on his own PC,but for more complex computation he can connect his PC to the server through the LAN.He can utilize computing power,all facilities and database available with the server.He can also avail the facilities available at other PCs connected to the server.The computer connected to the server through a network is called client.The aforesaid type of computing is known as client-server computing.

server room

BUS SYSTEM IN A MULTIPROCESSOR SYSTEM

A number of bus configuration are available for a multiprocessor system.Example are:single shared bus system,dual bus system,crossbar interconnection,hypercube system,etc. A few bus system are described below in brief.
Fig 1 shows a single shared bus architecture.In such a system one processor is allowed to communicate with the memory or another processor at any given time.since it is restricted to one transfer at a time,its data transfer rate within the system is limited by the speed of the single sheared us system.It has been used in computer system because it can easily be designed and controlled.

fig1: single-Bus System

Fig 2 shows a dual bus configuration.In this system local buses are employed.Each local bus is connected to a CPU,the local memory and I/O.A system bus controller connects each local bus to a common system bus.The memory and I/O connected to the common bus can be sheared by all processors.In this system only one CPU is allowed to communicate with the shared memory and other common resources through the system bus at any given time.The other processors use their local memory and I/O devices.It is an improvement over the single shared bus system.It has higher data transfer rate.But is a costly and complex bus system.

Phasor diagram of real transformer

Phasor diagram for the exact equivalent circuit of real transformer

Types of electrical switches

• SPST(single pole single throw)
• SPDT(single pole double throw)
• DPST(double pole,single throw)
• DPDT(double pole,double throw)

SPST(single pole single throw):The spst is a basic ON/OFF switch,that is used to connect or break the connection between two terminals.This type of switch has one i/p and one o/p.This type of switch circuit controls one wire and make one connection.

SPDT(single pole double Throw):The SPDT switch is a three terminal switch,one terminal is used as i/p and remaining two terminals are used as outputs.

DPST(double pole,single throw):The DPST switch consists of two poles that means it includes two identical switches located on side by side.This switch is operated by one single toggle,which means that two discrete circuits are controlled at a time through one push.

This switch is used to turn two circuits ON/OFF and it consists of four terminals namely two inputs and two o/ps.

DPDT (double pole double throw):This switch is equal to two SPDT switches,it means two separate circuits,connecting two inputs of each circuit to one of two o/ps.

when it is in ON-ON mode or ON-OFF-ON mode they work like two discrete SPDT switches worked by the similar actuator.

PLOTTERS

plotters are output devices.They are used to produce precise and good quality graphics and drawing under computer's control.They use ink pen or ink-jet to draw graphics or drawings.Either single color or multicolours  pens can be employed.The pens are driven by motor.Drawing can be prepared on paper,vellum or mylar (polyster film). colour transparency can also be prepared.
Pen plotters are slow devices.The graphics and drawing produced by pen plotters are uniform and precise,and they are of very good quality. they are used for low to medium volume job. A pen plotter can make from several seconds (for simple drawing) to several minutes (for complex drawings) to produce a drawing. ut it takes much  less time as compared to traditional hand methods  of producing drawings . A complex drawing which can take about a month by traditional hand method can be produced in less than an hour using plotters.

 the pen plotter may be classified into the following types:               

 Drum plotters:
A drum plotter contains a large cylinder and a pen carriage . the  paper is placed over the drum (i.e. cylinder). The drum rotates back and forth to give up and down movement . The pen is mounted horizontally on the carriage. The pen  moves along with the carriage left  to right or right to left on the paper to produce drawings . Under the computer control both the drum and the pen move to produce the desired drawings. Several pens with ink of different colours can be mounted on the carriage for multicolour drawings. Since each pen is program selectable, a multicoloured drawing can be produced.

Microgrip plotter:
 Such plotter don't use drums. The paper or any other medium is held(gripped) on both sides at the age y pinch wheels which give back and forth paper movement. With such plotters high performance is attained at a low cost.

Flat-Bed plotters:
Some  plotters employ ink-jets in place of ink pens. The paper is placed on a drum and the ink-jets with different-coloured ink are mounted on a carriage. Such plotters are capable of producing multicolour large drawings.   

USE OF COMPUTER IN COMMUNICATION

Computers are extensively used in sending and receiving information.The information transfer may take place either between two points or throughout a computer network that connects a number of computers or workstations.Data communication packages are available which are used to send and receive information.For communication purpose one must have a computer,a data communication package and a modem.Usually,telephones lines are used over which data are transmitted from one place to another.

The telephones lines are used over which data are transmitted from one place to another.The telephone lines have been built for voice transmission.To transmit human voice continuously variable analog wave patterns are used.Thus a telephone line is designed to transmit analog signals.on the other hand,a computer processes digital signal consisting of pulse or no pulse,i.e presence or absence of an electrical voltage.Digital signals can not be transmitted over existing telephone lines which have been designed to transmit analog signals.Hence,modems are needed to convert or modulate digital signals to analog signals and vice versa when exiting telephone lines are to be used.A modem connects a computer to the telephone lines.The modem receives data from a computer or a terminal which are to be transmitted over telephone lines.The modem converts(modulated) the digital signals into analog signals which can be transmitted over the telephone lines.The modem at the other end receives the data from telephone lines and converts (or demodulates) the received analog signals into digital signals.These digital signals are processed by a computer at the receiving end and they are reproduced as the original information.Data can be transmitted in both directions.A modem performs both tasks:modulation and demodulation.when data is being transmitted from an end,the modem placed at that end performs modulation.when data is received at an end the modem placed at this end performs demodulation.

                                                                                     

Arrays Vs Structures

Both the arrays and structure are classified as structured data types as they provide a mechanism that enable us to access and manipulate data in a relatively easy manner.But they differ in a number of ways.

1.An array is a collection of related data elements of same type.Structure can have elements of different types.

2.An Array is derived data type whereas a structure is a programmer-defined one.

3.Any array behaves like a built-in data type.All we have to do is to declare an array variable and use it.But in the case of a structure,first we have to design and declare a data structure before the variables of that type are declared and used.

Arrays

An array is a fixed-size sequenced collection of  elements of the same data type.It is simply a grouping of like-type data.In its simplest form,an array can be used to represent a list of numbers,or a list of names.

an array is a sequence collection of related data items that shear a common name.For instance,we can refer to the individual salaries of a group of employees in an organization.we can refer to the individual salaries by writing a number called index or subscript in brackets after the array name.For example,represents the salary of the 10th employee.while the complete set of values is referred to as an array,individual values are called elements.

The ability to use a single name to represent a collection of items and to refer to an item by specifying the item number enable us to develop concise and efficient programs.

we can use arrays to represent not only simple lists of values but also tables of data in two or three or more dimensions.the following types of arrays.

• One-dimensional arrays
• Two-dimensional arrays 
• Multidimensional arrays  

CATEGORY OF FUNCTIONS

A function,depending on whether arguments are present or not whether a value is returned or not,may belong to one of the following categories.

category 1: Functions with no arguments and no return values.

category 2: Functions with arguments and no return value.

category 3: Functions with arguments and one return value.

category 4: Functions with no arguments but returns value.

category 5: Functions that return multiple values.

Functions with no arguments and no return values:

when a function has no arguments,it does not receive any data from the calling function.similarly,when it does not return a value,the calling function does not receive any data from the called function.In effect,there is no data transfer between the calling function and the called function.This is depicted in fig.1.The dotted lines indicate that there is only a transfer of control but not data.

As pointed out earlier, a function that does not return any value cannot be used in an expression.It can only be used as an independent statement.

It is important to note that the function value receives its data directly from the terminal.The input data include principle amount,interest rate and the period for which the final  value is to be calculated.

 Functions with arguments and no return value: 

the main function has no control over the way functions receive input data.for example,the function printline will print the same line each time is called.same is the case with the function value,we could make the calling function to read data from the terminal and pass it on to the called function.This approach seems to be wiser because the calling function can check for the validity of data,if necessary,before it is handed over to the called function.

The nature of data communication between the calling function and the function with arguments but no return value shown in fig.

Functions with arguments and one return value:

pointers in C language

A pointer is a derived data type in C.It is built from one of the fundamental data types available in C.Pointer contain memory addresses as their values.since these memory addresses are the locations in the computer memory where program instructions and data are stored,pointers can be used to access and manipulate data stored in the memory.

pointer are undoubtedly one of the most distinct and exciting features of C language.It has added power and flexibility to the language.Although they appear little confusing and difficult to understand for a beginner,they are a powerful tool and handy to use once they are mastered.

Pointers are used frequently in C,as they offer a number of benefits to the programmers.

They include:

1.pointer are more efficient in handling arrays and data tables.

2.Pointer can be used to return multiple values from a function via function arguments.

3.pointers permit reference to functions and thereby facilitating passing of functions as arguments to other functions.

4.The use of pointer arrays to character string results in saving of data storage space in memory.

5.pointers allow C to support dynamic memory management.

6.pointers provide an efficient tool for manipulating dynamic data structures such as structures,linked lists,queues,stacks and trees.

7.pointers reduces length and complexity of programs.

8.They increase the execution speed and thus reduce the program execution time.of course,the real power of C lies in the proper use of pointers. 

Types of errors in C language

There might be many other errors,some obvious and other not so obvious.All these errors can be classified under four types,namely,syntax errors,run-time errors,logical errors,and latent errors.

syntax error :

Any violation of rules of the language results in syntax errors.The compiler can detect and isolate such errors.when syntax errors are present,the compilation fails and is terminated after listing the errors and line numbers in the source program,where the errors have occurred. Remember,in some cases,the line number may not  exactly indicate the place of the error.In other cases,one syntax error may result in a long list of errors.Correction of one or two errors at the beginning of the program may eliminate the entire list.

Run-time errors:Errors such as a mismatch of data types or referencing an out-of-range array element go undetected by the compiler.A program with these mistakes will run,but produce erroneous results and therefore the name run-time errors.Isolating a run-time error is usually a difficult task.

Logical errors:As the name implies,these errors are related to the logic of the program execution.Such actions as taking a wrong path,failure to consider a particular condition,and incorrect order of evaluation of statements belong to this category.Logical  errors do not show uo as compiler-generated error messages.Rather,they cause incorrect translation of the algorithm into the program and a lack of clarity of hierarchy of operators.

consider the  following statement

if(x==y)

printf("they are equal \n");

when x and y are float types values,they rarely become equal,due to truncation errors.The printf call may not be executed at all.A test like while(x!=y)might create an infinite loop.

Latent errors:It is a  'hidden'error that shows up only when a particular set of data is used. For example,consider the following statement:

ratio=(x+y)/(p-q);

An error occurs only when p and q are equal. An error of this kind can be detected only by using all possible combinations of test data.

AIRLINES AND RAILWAYS TICKET RESERVATION

Indian Railways have introduced computerized ticket reservation system at many important stations.The computer stores all necessary information in connection with ticket reservation,such as train number,station enroute,distance,number of seats available for each train in each class,fare etc.It also stores information regarding persons who have already reservation such as name of the passengers,age,destination,date of journey,class,fare,etc.The person sitting at the counter gets information immediately whether seats on a particular date in a particular trains are available or not.it also gives information regarding train timings,train fares etc.on inquiry.

Computers are also used for plane tickets reservation.The passengers can also book tickets for onward journey if computers are connected in a computer network for such a purpose.They can also get informations about seats in hotels in other cities,climate of other cities etc.through the computer network.

                                                                                           

ARTIFICIAL INTELLIGENCE

A machine with reasoning,learning and logic capability is said to possess artificial intelligence.For example,expert systems posses artificial intelligence.An expert system is a software which utilizes a knowledge base collected from human specialists in a certain area,and helps users refer to this expertise in making their own decisions.

An artificial intelligence system has a knowledge base and programming technique to probe and process the facts in the knowledge base.The development of a knowledge base is very difficult and time consuming job.To develop a knowledge base the designers and research workers consult experts of a particular field.They collect facts that are based on the knowledge and experience of the experts in that field.such a collection forms knowledge base.An expert system uses a knowledge base for its artificial intelligence.Besides expert's knowledge an expert system also uses the decision rules of human specialists to reach certain conclusion and to give recommendations.Natural language may be used to input the user's facts and queries.The recommendation made by an expert system is based on the collection of information in the knowledge base.Hence,the knowledge base must be updates regularly.An expert system select one of many opinions depending on input data and information.The machine uses a set of decision rules on logical basis to choose an opinion.The machine is designed to perform such logical functions.It asks users to supply information on a problem.Computer then processes the information and reaches conclusion making use of the  knowledge base.

Due to  various many organizations want to develop expert systems.If an expert retires,dies or resigns the organization looses his expertise.So this is a very good reason to preserve expertise of experienced specialist's expertise.Some examples of expert systems are as follows.

Several expert systems in various specialized fields have been developed and diagnose diseases and recommend treatment.An expert system called HELP has been developed to diagnose heart diseases.Another  expert package is PUFF which has been designed to diagnose lungs diseases.The expert system CADUCEUS is a generalized package.It can process and evaluate over 4000 symptoms and other information to diagnose over 600 diseases. 

Fifth generation of computer

The fifth-generation computers are under development stage.Japan and USA have undertaken to design and develop such computers.These computers will use ULSI (ultra-large-scale integration) chips. ULSI chips contain millions of components into a single IC.such computers will use intelligent programming,knowledge-based problem solving techniques,high  performance multiprocessor system and improve human-machine interfaces.The input and output information for these computers will understand natual languages like, english,japanese,etc.The programmers will not have to learn programming languages.They will be able to speak commands or key information in their mother tongues.Visions system will also be incorporated. A computers will use intelligent software.The intelligent software will have artificial intelligence.In intelligent programming the user will tell the computer what to do.He will not tell the user will not have the burden of programming.

In the last 40 years there have been many innovations,inventions and developments in the field of computer technology but still today most of the computers use von Neumann's architecture of digital computer.The first four generations of computers used this basic structure and design in which a processor executes simple instructions in a sequence.In a fifth-generation of computers a different design and architecture may be used.in such a design data flow architecture will be used.There will be extensive use of parallel processing.Special coprocessors will be developed to make logical inference and manage massive amounts of stored knowledge.These computers will be acknowledge-based computers. PROLOG is expected to play an important role in making logical inferences.Users will work in natural language like English,Japanese,etc.The language of operating system will be PROLOG  

SINGLE-CHIP MICROCOMPUTERS (MICROCONTROLLERS)

With the development of VLSI technology it became possible to fabricate a digital computer on a single IC chip.A digital computer fabricated on a single IC chip is called single-chip microcomputer.since it is widely used for control application,it is called microcontroller. It is very small and compact.It forms the part of the devices or equipment which is to be controlled.It is used for industrial control,process control,consumer and appliances control,instrumentation,etc.it contains a CPU,memory (RAM,and ROM/EPROM) and I/O lines.A powerful microcontroller may contain some other components which are needed for control application such as analog-to-digital converter,digital-to-analog converter,interrupt controller,DMA controller,wave generator,etc.

Intel developed 8-bit microcontrollers 8051 series was developed.8-bit microcontrollers are used for simple and low-cost control applications.In 1983,Intel developed 16-bit microcontrollers,8096 series.Later on,it developed 80196 series of 16-bit microcontrollers. These were more powerful and were used in sophisticated industrial control,intelligent computer peripherals,instrumentation,etc.

Other manufactures also developed 4-bits,8-bits,16-bit and 32-bit microcontrollers.Motorola developed 32-bit microcontrollers are used for complex control applications.