Black and white Computer

Analog data Analog data is refers to information that is continuous, example like the analog clock that has hour,minute and seconds hands that provide information in continuous form. Analog data like the sounds made by human voice, take on continuous values. when someone speaks, an analog wave is created in the air. This can be captured by a microphone and converted to an analog signal or sampled and converted to a digital signal. Analog Signals Analog signal is similar as data, an analog signal has infinitely many levels of intensity over a period of time, As the wave moves from value A to value B, it passes through and includes an infinite number of values along its path. Analog signal Periodic & non-periodic analog signals There are two type of analog signal which are periodic analog signal and non-periodic signals. The graph above you may think that is a non-periodic analog signal but it was a periodic analog signal because it repeats pattern over subseque

A substitution Cipher is a method of encryption by which units of plain text are replaced with cipher text.The receiver deciphers the text by performing an inverse substitution.For example, the letter "a" is encrypt to "z", while "b" change to "y" and so on. How To Break Substitution Cipher Most people break substitution cipher is using the frequency of English letter/alphabet. Use the frequency of letter Some research found that the most frequently used alphabet/letter in a text is "e" which is 12.7 %, the second letter is "t" is 9.7% ,third letter is  "a" 8.1%. Then we use the frequency of pair letter(digrams) like "he","an","in","th" .Following is looking for trigrams. This kind of attack is call the cipher only attack .

Recently I play Facebook games CheftVille, it was similar games like cityville, farmville and others. All the zynga game is officially SAME . However, I was not here to discuss about the zynga but about the facebook. This is the thing I saw when I click the game feed button at the apps category. I saw this...... When I saw this , I feel weird " promote this post" ? then I decide to check it out! Facebook is CREATIVE (ps:bold sometime is sarcasm). Do we really need this? Got people will use?

Depend on what operating System you are using , the French Accent Codes is different Operating System. For example in Windows, the combination between ALT key and a numeric code can be used to type a non- English Character (accented letter or punctuation symbol) in any Windows application. However the ALT method only work for keyboard with Numpad. For the laptop user then you should find another way to input the french accent codes. You can printout the picture below! While the Linux use different method than Windows . Since I was using Ubuntu therefore I not sure this method will work or not on others Linux distribute . Press Ctrl + Shift + U. Then a U with underscore will show!   U then type in the codes. The another way to input French in window is using the input keyboard provide by window . You can find it at Control panel. Open the Control Panel. Click Clock,Languages, and Regions. Click Region and Language. Click the tab keyboards and languages. C

Oracle SQL Developer is a free integrated development environment that simplifies the development and management of Oracle Database. SQL Developer offers complete end-to-end development of your PL/SQL applications, a worksheet for running queries and scripts, a DBA console for managing the database, a reports interface, a complete data modeling solution, and a migration platform for moving your 3rd party databases to Oracle. Oracle SQL Developer is a free graphical tool for database development. With SQL Developer, you can browse database objects, run SQL statements and SQL scripts, and edit and debug PL/SQL statements. You can also run any number of provided reports, as well as create and save your own. SQL Developer enhances productivity and simplifies your database development tasks.SQL Developer can connect to any Oracle Database version 10g and later and runs on Windows, Linux and Mac OSX. Oracle SQL developer cannot stand alone it should accompany with database syst

Raspberry Pi What is Raspberry Pi? Raspberry Pi is a computer with a credit-card size that can plug in TV and a keyboard! It's capable as others computer can do, for example spreadsheets,word-processing and even game! Raspberry make up It also plays high-definition video. Purpose of Raspberry Pi is to let kids all over the world to learn programming. Raspberry Pi recommend Debian as our default distribution, Raspbian is optimised version of Debian . It’s straightforward to replace the root partition on the SD card with another ARM Linux distro if you want to use something else (there are several available on our downloads page). The OS is stored on the SD card. Raspberry pi have 2 model,Model A and Model B. Model A used to be 128Mb Ram but it has been redesigned to have 256Mb RAM, one USB port and no Ethernet (network connection). Model B has 256Mb RAM, 2 USB port and an Ethernet port.The Model A will cost $25 and the Model B $35, plus local taxes.The Raspberry Pi

Transmission Control Protocol (TCP) also known as Transport Protocol. TCP is one of the two original components of the suite, complementing the Internet Protocol (IP), and therefore the entire suite is commonly referred to as TCP/IP.Transmission Control Protocol is built on top of IP. Protocol mean the rules in order two devices or more to communicate with each others.In others meaning, Devices with TCP can only communicate with devices equip with TCP. For example like human communication in same using English as Global language then TCP is similar with english! Function of Transmission Contol Protocol: It will assume that IP might lose some data ,so it will keep a copy of data and send data to receiver until get an acknowledgement from the receiver. If the data sent is unresposive for too long , the TCP will send it again. The responsibility of the transport layer is to present a reliable end to-end pipe to the application.The data either arrives in the proper order or the