1. What's active mode and passive modea. FTP has two ports to control:Port 20 is for data transferPort 21 is for control or establish TCP connectionb. The process of active connectionNote: C represents Client and S represents ServerS opens port 20 and 21C connects to port 21 of S with a random port, this port can be between 1024 and 65536, it sends port+x to server at the same time to specify C(X)->S(21)When S receives the command, it will sends back ACK, S(21)->C(X)S will set up a connection between its port 20 and client's X+1, S(20)->C(X+1)C responds with an ACK,C(X+1)->S(20)c. ...

According to EETimes, Lenovo will enter the field of chip design, the main focus is the smartphone and tablet chip design.There is a small team of 10 people who are working on integrated circuit design in Lenovo in the past 10 years, Till the middle of this year, Lenovo intends to expand the team to 100 engineers. Lenovo may recruit 40 engineers in Shenzhen and 60 engineers in Beijing.Despite Lenovo has much freedom in the choice of application processors, but because it involves a competitive relationship, It's difficult for Lenovo to get the latest version of the processor. For example, Sams...

Quitting from Google and joined Yahoo which was thought as a declining giant, Marissa Mayer has been trying to prove that she has the ability to lead this Internet giant to reverse the decline. In order to boost the low morale of the employees, Meyer tried to transplant Google's work culture to Yahoo with office decoration, free lunch and issuance of smart phones, these generous measures let her win the applause of the Silicon Valley.But a recent ban issued by Meyer has attracted a lot of controversy because she touched one invisible welfare of Silicon Valley employees: work from home. Meyer d...

The whole boot process of computer can be summarized in 4 phases.1. BIOSIn the 70's  read-only memory(ROM) was invented. The boot program is written into ROM, the first thing the computer does is to read and execute this program when it's powered on.The program in this chip is called "Basic Input/Output System" (BIOS).1.1 Power-On Self-TestThe BIOS will first check whether the computer hardware can fulfill the basic conditions for booting up, this process is called Power-On Self-Test, simplified as POST.If the hardware has problems, the mother board will produce different beeps and the bo...

Asus and Acer are the last two manufacturers of netbooks, but these two companies announced that they would not manufacture netbooks starting from January 1, 2013. Prior to them, Samsung, Hewlett-Packard and Dell stopped production of the netbooks. This means that the life cycle of netbook officially ended.Back to 2009, the U.S. market research firm ABI Research was very optimistic about netbook's future, they said netbook would open a new era for PC market and predicted netbook shipments would reach 139 million units in 2010. But the end result was netbook shipments units were only 39.4 milli...

Nielsen released the 2012 digital industry rankings report, The report said Google continued to rank No.1. for web brand From January 2012 to October 2012, the average monthly unique visitors reached 172 million. Followed by Facebook which has 153 million average monthly unique visitors. In 2012, the online video service continues to grow, YouTube is still the largest online video site, an average annual 132 million unique visitors.Top 10 U.S. Web Brands of 2012For the details of other ranks and analysis. Please read more here.Source : http://www.36kr.com/p/200330.html...

Although there is rapid revolution for new technology, some technologies can survive with the passage of time. Here are 10 modern technologies which may continue to exist in 2030.1. QWERTY keyboardSpeech recognition, handwriting recognition and gesture control input will become the trend for the next two decades. Nonetheless QWERTY keyboard input is still one of the most accurate way - although not necessarily the most convenient.Although physical keyboard disappear on phones and tablet PCs, the real plastic key feeling will not be exceeded on laptops and desktops. It first appeared in 1878 an...

xkcd is a webcomic created by Randall Munroe. The comic's tagline describes it as "a webcomic of romance, sarcasm, math, and language." Also some webcomics about IT may frequently appear on it. For example, the following one-- People who know Unix will understand it easily.In fact, xkcd is a Geek culture, many comics inside this site can only understood by some specified group of people.The comic began in September 2005 when Munroe decided to scan doodles from his school notebooks and put them on his webpage. Eventually the comic was changed into a stand-alone web...