History of Computers

Computers we use today are not necessarily just show up but through a long process of evolution. Happenings emergence of the computer may be viewed in flashback history since the use of Abacus - found in Babylon (Iraq) about 5000 years ago - as a means of manual calculation of the first, both in the scope of the school and among traders, at the time.

At a later period has been widely found in the means of calculating the mechanical kind that is Pascaline invented by Blaine Pascal in 1642, arithometer by Charles Xavier Thomas de Colmar in 1820, Babbage's Folly by Charles Babbage in 1822, and Hollerith by Herman Hollerith in the year 1889.

All are still a machine entirely without electricity. The size and complexity of its structure based on calculations performed the operation level. It was only in 1940, began a new era since the invention of electrical computer electrically computers that implement Boolean algebra.

The development of computer technology which is described below in the top four generations based on the components it uses, ranging from the size of "big" to micro-line also with the complexity of its components.

First Generation
Today is the era giant computers, such as Z3, Colossus, ENIAC, EDVAC, EDSAC, UNIVAC I. Characteristics of computers in this era marked by the size almost as big as the bedroom, using a vacuum tube with a number of very much to store and process the orders or instructions, consuming thousands of watts of electric power, using machine language and can only be used by a person trained.

So, the layman would not be able to use it so that computers of this type has not been commercialized to the general public. Only large corporations, educational institutions and government agencies that use it.


Second Generation
This era began with the use of transistors and diodes as a replacement of vacuum tube that sizenya smaller than its predecessor generation.

Another invention is the use of magnetic core memory that hold data, so much faster in data processing, and machine language has been replaced with assembly language (Fortran and Cobol) that facilitate the operation. Some examples of the computer at this time, the Stretch, LARC, DEC PDP-8, IBM 1401, IBM 7090 and IBM 7094.


Third Generation
A new era of computer communication set foot on the momentum from this. Most large companies implement on-line system using a remote terminal in the use of computers (read: on-line).

This technology must be supported by an increasingly computer performance in terms of both hardware and software usage. New discoveries in the field of hardware acted with the emergence of IC (Integrated Circuit) in computer components.

Because of its advantages in uniting the various components in a single chip so that the computer at the time computers became ever smaller size without degrading the performance of the output, and even further improve its performance.

In the software, programming techniques plural (Multi-Programming) began to be developed so that more and add a collection of various existing programming languages. Cray-1, 90/30 UNIVAC and IBM 360 is a few examples of computers in this generation.


Fourth Generation
Along with the speed of time development of the computer as a tool of data processing has increased rapidly, especially in this generation. The growing speed is inversely proportional to the smaller size, supported by a larger memory capacity. The price is getting cheaper due to its components have been manufactured and sold in mass.

In this period various IC united into a single unit forming a component called the VLSI (Very Large Scale IC). Use of the software more easily and develop into effect on home computers, such as word processing and spreadsheet. Internet network was more extensive that previously only enjoyed by the elite groups now can be used also by ordinary people.

The use of microprocessor is now an absolute no longer used only on computers but has been applied to other electronic products, such as televisions and microwaves. Seeing the development of the computer world a very high rate of growth starting from the beginning to the present generation can we predict how the characteristics of the computer on future generations.

Possibly, the computer will not have to continue to be dictated by the man but he had to do everything yourself. Virtually ability already resembles human intelligence. Such capabilities (Artificial Intelligence or Artificial Intelligence) is now actively investigated by the developed countries like Japan and the United States.

Author

Azhar H. Bakrit

History of Computers

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COMPUTER NETWORK TECHNOLOGY

COMPUTER NETWORK TECHNOLOGY

A. Preliminary
Computer networks is not something new today. Almost in every company there is a computer network to facilitate information flow within the company.

Internet is gaining popularity today is a giant computer network which is a network of computers connected and can interact with each other. This can happen because of the development of network technologies very rapidly, so that within a few years the number of users of computer networks belonging to the Internet doubled.

B. Computer Networking
1. Definition
Computer network is a collection of computers, printers and other equipment are connected. Information and data moves through the wires to allow users of computer networks can exchange documents and data, print on the same printer and share the hardware / software that connects to the network.

Each computer, printer or peripherals that connect denganjaringan called nodes. A computer network can have two, tens, thousands or even millions of nodes. A network typically consists of 2 or more computers that are interconnected among each other, and share resources such as CD-ROM,

Printers, exchange files, or the ability to electronically communicate with each other. Computers that connect those, made possible with the media cables, telephone lines, radio waves, satellite, or infrared rays.

2. Network Types
There are 3 kinds of Networks / Network are:
a. Local Area Network (LAN) / Local Area Network.
A LAN is a network that is limited by a relatively small area, generally bounded by the area like an office environment in a building, or a school, and usually not far from about 1 km square.

Several models of LAN configuration, one computer is usually made in a file server. Which is used to store software (software) that regulate network activity, or as software that can be used by komputerkomputer that is connected to the network.

The computers are connected to the network (network) is usually called a workstation. Workstation capabilities more usually under the file server and have other applications in the hard drive in addition to applications for the network. Most LANs use the media cable for connecting between one computer to another computer.

b. Metropolitan Area Network (MAN) / Metropolitan area network

A MAN, usually covering a larger area than a LAN, for example between regions within a province. In this case the network connecting several small networks into larger areas of environment, for example are: network

Bank where several branches of a bank in a big city is connected between each other. For example, Bank BNI in the entire region or Surabaya Ujung Pandang.

c. Wide Area Network (WAN) / Large Scale area network

Wide Area Networks (WAN) is a network that already use a scope usually means satellite or submarine cable as an example of the whole network BANK BNI in Indonesia or in other countries.

Using the WAN facilities, a bank in Bandung can contact its branch offices in Hong Kong, just a few minutes. WAN usually rather complicated and very complex, using many means to connect between LAN and WAN to the Global Communications such as the Internet.

But somehow between LAN, MAN and WAN are not much different in some respects, only the scope of the area is just a different one among others.

3. Protocol

Protocol is a set of rules that govern communications between computers on a network, the rules include guidelines that apply to the ways or methods of accessing a network, physical topology, the types of cable and data transfer speeds.

Protocols supported are as follows:
1. Ethernet
2. Local Talk
3. Token Ring
4. FDDI
5. ATM


Ethernet
Ethernet protocol is by far the most widely used, the Ethernet access method called CSMA / CD (Carrier Sense Multiple Access / Collision Detection). This is a system where each computer listens to the cable network before sending anything into it.

If the network is clear, the computer will transmit the data, if there is another transmission on the cable, the computer will wait and will try to re-transmission if the network has been clean.

Sometimes, two computers transmit at the same time, when this happens, each computer will be back and will wait a random chance to transmit data back. This method is known to the coalition, and will not affect the speed of transmission on the network.

The Ethernet protocol allows for linear bus, star, or tree. Data can be transmitted over twisted pair cable, coaxial, or fiber optic cable at speeds of 10 Mbps.

COMPUTER NETWORK TECHNOLOGY

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AVR Microcontroller Programming with C

Programming Language C for AVR widely used C language for programming a variety of devices, including microcontrollers. This language is already a high level language, which allows programmers pouring algorithm. To know basic C language can be studied as follows.

1. Coding Structure
# Include <[library1.h]> / / Optional
# Include <[library2.h]> / / Optional
# Define [name1] [value]; / / Optional
# Define [name2] [value]; / / Optional
[Global variables] / / Optional
[Functions] / / Optional
void main (void) / / Main Program
{[Declaration of local variable / constant] [Contents Main Program]}

2. Data type
char: 1 byte (-128 s / d 127)
unsigned char: 1 byte (0 to 255)
int: 2 bytes (-32 768 s / d 32 767)
unsigned int: 2 bytes (0 s / d 65 535)
Long: 4 bytes (-2,147,483,648 s / d 2147483647)
unsigned long: 4 bytes (0 to 4,294,967,295)
float: decimal
array: a collection of the same data type.

3. Declaration of variables and constants
The variable is a data storage memory whose value can be changed.
Writing: [Data type] [name] = [value];
Constant is data storage memory whose value can not be changed.
Writing: const [name] = [value];
Supplement: Global variables / constants that can be accessed throughout the program.
Local variables / constants that can only be accessed by the function of the declaration.

4. Statement
Statement means any operation in programming, should end with [;] or [}]. Statement will not be executed if preceded by a [/ /] for a single line. More than 1 line to use the couple [/ *] and [* /]. Statement is not executed is also called comments / commentary.
Example: temperature = adc/255 * 100; / / example of formula calculation temperature

5. Function Function
is part of a program that can be called by the main program.
 Writing: [type data] [function name] ([type of data input 1], [type of data input 2]) {[statement];}

6. Conditional if else statements and loops
used for the selection condition
if ([requirements]) {[statement1]; [statement2];} else {[statement3]; [statement4];}
for: used for loops with a known amount
for ([initial value]; [requirements]: [the operation value]) {[statement1]; [statement2];}
while loop: used to loop if and flesh, certain eligible
while ([requirements]) {[statement1]; [statement2];}
do while loop: used to loop if and flesh meet certain requirements, but min 1 time
do {[statement1]; [statement2];} while ([requirement])
switch case: used for selection with many conditions
switch ([variable name]) {case [value1]: [statement]; break; case [value2]: [statement]; break;}

7. Operation logic and binary logic
AND: & &
NOT:!
OR: | |
Binary AND: &
OR: |
XOR: ^
Shift right:>>
Shift left: <<
Complement: ~

8. Relational operations (comparisons)
Equal to: ==
Not equal:! =
Bigger:>
Bigger equals:> =
Smaller: <
Smaller equal to: <=

9. Arithmetic operations
+, -, *, /: Add, less, times, for
+ =, -=, *=, / =: Value to the left of the operator on the plus / less / multiply / divide by the value of the right of the operator
%: Remainder for
+ +, -: Plus one (increment), less one (decrement)
Example:
a = 5 * 6 + 2 / 2 -1;
then the value of a is 30 a *= 5;
if the initial value of a is 30, then the value of a = 30x5 = 150. a + = 3;
if the initial value of a is 30, then the value of a = 30 +5 ​​= 33. a + +;
if the initial value of a is 5 then the value of a = a +1 = 6. a -;
if the initial value of a is 5 then the value of a = a-1 = 4.

AVR Microcontroller Programming with C

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Mystery Numbers : Zero

Yusmichad Yusdja, staff researcher at the Center for Research and Social and Economic Development of Agriculture IPB

Hundreds of years ago, people only Knew the 9 symbol numbers 1, 2, 2, 3, 5, 6, 7, 8, and 9. Then, come the number 0, so the number of symbol numbers into 10 pieces. It is unknown WHO's the creator of the number 0, the only historical evidence shows That the number 0, first discovered in ancient Egyptian times.

At That time only as a symbol number zero. In modern times, the number zero is Used not only as a symbol, but Also as the number WHO participated in mathematical operations. Now, use the number zero has infiltrated deep into the joints of human life.

Counting system is no longer possible to ignore the presence of zero, although zero-one made a mess of logic. Let's see.

Zero, cause crashes

Lessons about the number zero, from ancient times Until now always cause confusion for students and students, and even the user community. Why? Is not zero-one represents something That does not exist and That nothing was there, namely zero.

Who is not confused? EACH time the number zero appears in mathematics there is always a weird idea. Like the idea if something is multiplied by 0 then Becomes not exist. Could it be 5 * 0 to not exist? (* Is multiplication). This idea makes people frustrated. Is zero magician?

Worse yet-confused-why Would increase is 5 +0 = 5 and 5 * 0 = 5 as well? Indeed Such a rule, Because of zero in multiplication is the identity numbers are equal to 1. So 5 * 0 = 5 * 1. However, it is true That Also 5 * 0 = 0. Waw. What about 5o = 1, but 50o = 1, too?

a, never mind. Another rule of zero the which is mysterious Also Is That a number is divided by zero if not defined. That is, whatever number That cans not be divided by zero. Sophisticated computer earnest Suddenly somehow die if a sudden meeting with a zero divisor. Computers are ordered to stop to think if he met the divisor is zero.

Numbers zero: homeless

Numbers have been Prepared based on the hierarchy by a single straight line. At the starting point is the number zero, then number 1, 2, and so on. Greater numbers on the right and a Smaller numbers on the left. The farther to the right will from some events this Greater number.

Based on the degree of hierarchy (and bureaucracy numbers), a person walking from point 0 if continually Towards Greater numbers to the right earnest reach the numbers the which do not infinite. However, that person May Also come to the point 0 again.

Is not this world round? Could it be? Columbus Did not Say That if he kept sailing Until Would he return to Europe?

Another. If someone departs from zero, it is not possible Until the number 4 without first passing numbers 1, 2, and 3. But more strange is the question of possible Could someone go from point zero?

Obviously not, Because it is not the point of zero point something That does not exist? Strange and hard to believe? Let's look Further.

If in Between two numbers or Between two points there is a segment. EACH number has a vertebra. If this segment is cut into pieces and then a black circle dots Moved into the middle segment, was number 0 does not have sections. Thus, the number zero was in the clouds.

Numbers zero alias has no homeless shelter. That is why, why the number zero Should Be attached to another number, for example, in figure 1 form the number 10, 100, 109, 10 403 and so forth. So, one cans never go from zero to the number 4. We must Depart from the 1.

Easy, but wrong

The teacher ACKs the Ani describes a geometric lines of the equation 3x +7 y = 25. Ani think That to get a line That needed two points from end to end. However, after the count is calculated, it turns out there's only one point passed the line, ie, point A (6, 1), for x = 6 and y = 1. So That Annie cans not make the line.

The teacher warned That using the number zero. Yes, that's the way out. First, give y = 0 obtained by x = (25-0) / 3 = 8 (rounded), is the first point, B (8.0). Furthermore, given x = 0 obtained by y = (25-3.0) / 7 = 4 (rounded), is the second point C (0,4). Line BC, is the line in question. However, how disappointed the teacher, Because the line was not through point A. Thus, the BC line is wrong.

Ani defend themselves That the error was very small and cans be ignored. Teachers stated That it was not a small amount of Mistakes, but Nowhere Is That correct? Is not the line BC cans be made through the point A? Said the teacher, use the number zero in the right way.

How do We have to help Annie make the correct line is? Easy, says consultant Mathematics. At first the value of 25 in 3x +7 y Should Be Replaced with the result of multiplying 3 and 7 That obtained 3x +7 y = 21.

Furthermore, in the new equation, given y = 0 obtained x = 21 / 3 = 7 (without rounding) was the first point P (6.1). Then give the value x = 0 obtained by y = 21 / 7 = 3 (without rounding), that's the second point Q (0, 3).

The line PQ is a line parallel to the line to be searched, namely 3x +7 y = 25. Through point A drag line parallel to PQ obtained P1Q1 line. Well, that's it. The students have found the correct line thanks to the help number zero.

However, the teacher was very disappointed Because no one Actually Had the correct line. Is not in the equation 3x1 +7 x2 = 25 'there is only one solution That point is point A, the which means the equation 3x1 +7 x2-shaped it's just a point?

Even in the equation 3x1 +7 x2 = 21 does not exist a point no matter Who is in line PQ. Therefore, the line PQ in the system of integers, does not really exist. Strange, the number zero has deceived us. That fact, the equation does not always form a line.

Moving, but stationary

Numbers do not only consist of integers, but Also there is a decimal number, Among others, from 0.1, 0.01, 0,001; and so strong-as strong as We can call it up so small. Since very little cans no longer be Called or not infinite and in the end it is Considered zero.

But this idea turned out was confusing Because if an infinitely small number treated as zero then means zero is the smallest number? In fact, the zero represents something That does not exist? Waw. That's it.

Based on the concept of decimals and continuous, then We use the number line is not That Simple Because Between two numbers there is always a number to three. If someone jumped from number 1 to number 2, but with the condition have to jump over Them first to the nearest decimal, can he?

What is the nearest decimal before it reached the number 2? It Could Be the number 1 / 2. However, you Should not jump to number 1 / 2 Because there is still a Smaller numbers, namely 1 / 4.

So there is always a number That more closely ... namely 0.1 and then there are 0.01, 0.001, ..., 0.000001. and so on, so That eventually the number closest to the number 1 is so small That number is Considered to be zero. Because the nearest number is zero alias does not exist, then you cans never jump to number 2?

Mystery Numbers :  Zero

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Mystery of Black Holes Numbers: 123

In astronomy and physics, we know of the existence of a natural phenomenon that is very interesting that a black hole (black hole). Black hole is an entity that has a very strong gravitational fields so that every object that has fallen in the area of ​​event horizon (the area around the core of a black hole), will not be able to escape again. In fact, any electromagnetic radiation such as light can not escape, resulting in a black hole becomes "invisible."

Apparently, in mathematics there is also a unique phenomenon that is similar to the phenomenon of black hole that is the number of black holes. How real numbers that black hole? Let us briefly playing with numbers.

Try to choose as they pleased you a natural numbers (numbers from 1 to infinity). For example, let's say 141,985. Then count the number of digits is even, odd digits, and the total number of digits.

In this case, we get 2 (two-digit even-numbered), 4 (four digits odd), and 6 (six is ​​the total number of digits). Then use these digits (2, 4, and 6) to form the next number, namely 246.

Repeat count the number of digits is even, odd digits, and the total number of 246 digits in this. We get 3 (digits even), 0 (odd digits), and 3 (the total number of digits), so we get 303.

Repeat again count the number of digits is even, odd, and the total digits in the number 303. (Note: 0 is an even number). We get 1, 2, 3 which can be written 123.

If we repeat the steps above to the number 123, we will get 123 again. Thus, the number 123 through this process is a black hole for all other numbers. All numbers in the universe will be drawn into numbers 123 through this process, none of which would qualify.

But was it all the numbers would be 123? Now let's try a very large number of value, for example, say 122333444455555666666777777788888888999999999.

The number of digits is even, odd, and the total is 20, 25, and 45. So, the next number is 202 545. Do more iterations (repetitions), we get 4, 2, and 6, so now we get 426. Iteration once again to 303 and 426 will result in the last iteration of 303 will be obtained 123.

Up to this point, no matter how many times iteration of the 123 will still be obtained by 123 again. Thus, 123 is the absolute point of the black hole in the world of numbers.

However, whether there may be a number, tucked between the jungle numbers which the universe is infinite, which can escape from the bondage of death the number of black holes, the 123 which is mysterious?

Mystery of Black Holes Numbers: 123

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What is radiocarbon dating technique can be used to find out what age?

This technique will not help us if we want to know is still in his life, such as friends talked us through the Internet that claim to 25 years. Determination of age using radiocarbon dating techniques (radiocarbon dating) is useful to determine the remaining life of plant or animal that died about five hundred to fifty thousand years ago.
Since the discovery by a professor of chemistry University of Chicago, Willard F. Libby (1908-1980) around 1950s (he received the Nobel Prize for the discovery in 1960), radiocarbon dating techniques have become very powerful tools in archaeological research, oceanography, and several other disciplines.

 For radiocarbon dating techniques to tell the age of an object, that object must contain organic carbon, namely carbon which had been part of the body of plants or animals. Radiocarbon dating methods tell us how long ago the plant or animal life, or more precisely, how long ago the plant or animal dies.
Radiocarbon test can be conducted on materials such as wood, bone, charcoal from the hearth of ancient camp or cave, or even a linen cloth used to wrap mummies, because the linen cloth made from flax plant fibers.
Carbon is a chemical element that was conceived by every living creature in the form of various biochemical substances, in proteins, carbohydrates, lipids, hormones, enzymes, etc.. Indeed, the study of chemistry of carbon-based chemicals called "organic chemistry" because once people believe that the only place for these chemicals are living creatures.
Now, people know that we can make all kinds of carbon-based organic chemicals from petroleum without having to take of plant or animal.
However, carbon in living things differ in one important case of carbon in the materials are not living things such as coal, petroleum, and minerals. Carbon "live" carbon atmospheres containing small amounts of certain types called carbon-14, while the carbon "dead" only contain atoms of carbon-12 and carbon-13.
The three kinds of different carbon atoms are called isotopes of carbon, they all behave the same chemically, but have a different weight, or more precisely, have different masses.
What is unique about the carbon-14, in addition to its mass, is because they are radioactive. Namely, they are unstable and tend to become weak, fragmented firing subatomic particles: particles called beta.
Thus all living things actually are radioactive, although few, that is because it has a carbon-14. Yes, including you and me, we are all radioactive. People with a weight of 68 kg contains about a million billion atoms of carbon-14 that fired a 200 000 beta particles every minute!

What is radiocarbon dating technique can be used to find out what age?

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Know Hydrogen Peroxide (H2O2)

Hydrogen peroxide with a chemical formula H2O2 was found by Louis Jacques Thenard in the year 1818. This compound is an inorganic chemical that has powerful oxidizing properties. Raw material of hydrogen peroxide is hydrogen gas (H2) and oxygen gas (O2). The technology is widely used in the auto industry is the hydrogen peroxide oxidation of anthraquinone.

H2O2 is colorless, odorless typical slightly acidic, and dissolves well in water. Under normal conditions (ambient conditions), hydrogen peroxide is very stable with decomposition rate of approximately less than 1% per year.

The majority of the use of hydrogen peroxide is to utilize and manipulate the decomposition reaction, which essentially produces oxygen. In the production phase hydrogen peroxide, chemical stabilizer ingredient is usually added in order to inhibit the rate of decomposition.

 Including the decomposition that occurs during the hydrogen peroxide product in storage. In addition to producing oxygen, hydrogen peroxide decomposition reaction also produces water (H2O) and heat. Exothermic decomposition reaction that occurs is as follows:

H2O2 -> H2O + 1/2O2 + 23:45 kcal / mol

Factors that affect hydrogen peroxide decomposition reaction is:

1. Certain organic materials, such as alcohol and gasoline
2. Catalysts, such as Pd, Fe, Cu, Ni, Cr, Pb, Mn
3. Temperature, hydrogen peroxide decomposition reaction rate increased by 2.2 x every increase of 10 ° C (in the temperature range 20-100oC)
4. Container is an uneven surface (active surface)
5. Suspended solids, like dust particles or other impurities
6. The higher the pH (more alkaline) the higher the rate of decomposition
7. Radiation, especially radiation from the light with short wavelengths

Hydrogen peroxide can be used as a bleaching agent or bleaching agent in pulp, paper and textiles. These compounds are also commonly used in wastewater treatment processes, chemical industry, the manufacture of detergents, food and beverage, medical, and electronics industries (manufacture of PCBs).

One of the benefits of hydrogen peroxide compared with the other oxidant is its environmentally friendly because they do not leave harmful residues. Oksidatornya strength also can be adjusted as needed.

For example in the pulp and paper industry, the use of hydrogen peroxide is usually combined with NaOH or caustic soda. The more alkaline, then the hydrogen peroxide decomposition rate even higher. Hydrogen peroxide industry needs will continue to increase from year to year.

Although currently in Indonesia already have several factories producing hydrogen peroxide as PT Peroxide Indonesia Pratama, PT Degussa Peroxide Indonesia, and PT Inti Samator Peroxide, but domestic demand still remain to be imported.

Know Hydrogen Peroxide (H2O2)

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