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  How does computer boot up?

The whole boot process of computer can be summarized in 4 phases. 1. BIOS In 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-Test The BIOS will first check whether the computer hardware can fulfill the basic conditions for booting up, this process is called Power-On Self-Test...

   Computer, boot, partition     2013-02-23 23:19:47

  Some tricks and tips for using for range in GoLang

GoLang provides two major ways to loop through elements of array, slice and map. They are for and for range. Many people find that for range is very convenient when don't care about the index of the element. In this post, some tricks and tips would be talked about regarding for range. 1. Loop and get pointer of each element Assume there is a code snippet like below which is to get the pointer of each element in an array and create a new array with the corresponding pointer. arr := [2]int{1, 2} r...

   POINTER,FOR LOOP,GOLANG,FOR RANGE     2020-03-08 01:07:00

  How to secure an Ubuntu Apache web server

Securing server software is not a straightforward task. Not all of our operating environments are the same, leading to a variety of potential security vulnerabilities. However, using a few basic configuration and security options, you can stay a little ahead of where you want to be. 1. Fail2ban Fail2ban is a Python-based intrusion prevention software that detects and blocks malicious IP addresses from multiple unsuccessful attempts at software logins. In other words, if someone is attempt...

   Unix server security,Log,.htaccess,Cache     2011-12-27 09:25:32

  Parallel Javascript

Lately the ideas for a parallel, shared memory JavaScript have begun to take shape. I’ve been discussing with various JavaScript luminaries and it seems like a design is starting to emerge. This post serves as a documentation of the basic ideas; I’m sure the details will change as we go along. User Model The model is that a JavaScript worker (the “parent”) may spawn a number of child tasks (the “children”). The parent is suspended while the children exe...

   Parallel JavaScript,API,Spawn,Parent,Task     2012-01-11 12:02:00

  What you may not know about PHP session

When we access one website, the site usually should have a mechanism to keep track of the status of the user on the site. There are a few mechanisms supported by many server side languages to help track user status such as session and cookie. Today we will talk about session, when creating a session, we need to keep track of many data, besides user data, we also need to tell the server what is the timeout of the session so that we can garbage collect the session data which should not be stored a...

   PHP session,session timeout,example     2013-07-06 08:44:18

  Will tablet revolution really come soon?

The famous Silicon Valley entrepreneur and academic Vivek Wadhwa said a few months ago that tablet revolution would come only if the price dropped below $100. According to The Wall Street Journal, the 4th largest PC manufacturer Acer seems to be the first one to eat crab. It plans to promote $88 Android tablet Acer Iconia B1. Does this indicate that the tablet revolution is coming? According to a person who knows the Acer tablet project, Acer Iconia B1 configuration will be similar to those of ...

   Acer,Tablet,Low price,Tablet revolution     2012-12-24 20:51:33

  Advantages and disadvantages of GoLang

GoLang is a strong typed language which means it is less flexible than interpreted languages by nature. But Go provides Any type(interface) and Reflect mechanism which make the language very close to interpreted languages on flexibility. More and more people start to learn GoLang. This post is mainly for listing down some of the advantages and disadvantages of GoLang. Advantages Performance(Machine code) GoLang is a compilation language which can be compiled to machine code and the compiled bina...

   GENERICS,GOROUTINE,GOLANG,DISADVANTAGE,ADVANTAGE     2018-11-10 20:46:45

  Misunderstanding about Android UI design

A few days ago I wrote a post trying to correct a lot of the inaccurate statements I have seen repeatedly mentioned about how graphics on Android works. This resulted in a lot of nice discussion, but unfortunately has also lead some people to come up with new, novel, and often technically inaccurate complaints about how Android works.These new topics have been more about some fundamental design decisions in Android, and why they are wrong. I’d like to help people better understand ...

   Android,UI,Priority,Background job,Smooth     2011-12-09 02:30:25

  JavaScript efficiency catch up

JavaScript is a very flexible language, we can write JavaScript code freely with various styles, different kinds of codes will have different execution efficiency. Here we summarize some tips we get from our development. Efficiency of JavaScript itself JavaScript has execution context chain, closures, prototype inheritance, eval etc. It brings us some magic features, but it also introduces the performance issue, if we don't use them properly, it will affect the codes execution efficiency. 1. Glo...

   JavaScript,efficiency,event delegation,eval     2013-04-02 04:08:46

  Windows Control panel mail icon

The exact location depends on your version of Windows and your layout settings of Control Panel. If your Control Panel is in the classic layout, you should see the Mail applet directly in the list of icons. For a 64-bit version of Windows Vista, the icon would be listed in the “View 32-bit Control Panel Items” section. If your Control Panel is in category view you can find the Mail applet in; Windows XP: User Accounts Windows Vista: User Accounts Windows Vista 64-bit: Additional O...

   Windows,Control panel,Mail icon,Outlook     2011-04-26 06:15:05