JTAG Cables and Programmers

JTAG is a popular serial interface used in professional embedded systems and commercial electronic devices. It is used to program, read and debug on-board electronics. Since all chips on the circuit board can be connected in a chain there is only one JTAG connector needed. Unfortunately this connector is not standardized and there are many different pinouts used. Different pinouts and different applications have resulted in many JTAG programmers for specific devices.

A popular use of JTAG cable is to program routers and Xbox devices. In fact, almost all programmable electronic devices support JTAG interface, but the connector is not always implemented. While the JTAG itself is standardized there is no universal programmer. You will have to get one for each device type you need to program.

The simplest JTAG programmer is only an interface between parallel port and JTAG. A software running on PC controls signals on parallel port which via JTAG interface control JTAG signals. A more sophisticated JTAG interface has own microcontroller and connects to PC via USB. JTAG programmers/interfaces are cheap and you can even build a simple JTAG cable!

Digital Data Recovery - Problems and Solutions

Computers are used even in places where we wouldn't expect them like in appliances. Computers make devices more intelligent but also more vulnerable in the case of failure. Take a look at digital cameras. We use giant flash memory cards that can store thousands of images. We expect that they will stay there until we will delete them. However, any camera malfunction may corrupt memory card data and erase files. Fortunately, digital images form memory cards can be recovered. This is possible because in order to completely erase files the memory card would have to be overwritten with new data. In the case of failure this is not what has happened. Usually there is only some corruption at the file system level which can be fixed by digital data recovery.

The same principle applies to hard drives. All the files saved there will remain where they are until the data is overwritten. Even when you delete file the data remains there, only the file becomes marked as deleted and thus invisible to the operating system. This principle is used to recover files from hard drives and other storage media. However, it can happen that hard drive fails completely. It may be because the electronics has failed or there is some mechanical problem. Fortunately, the data is still saved on the disk platters. The only problem is that we can not access it. The only solution to get the files is to repair the hard drive to the level the data can be read. This can be done by any hard drive data recovery service. They have all the tools and knowledge to recover digital data from hard drives and other storage media.

To prevent data loss there is one simple and effective solution. It is called data backup. All you have to do is to regularly back up all the important data. It is enough to copy important files to a CD or DVD. Another step in securing the data is to create complete disk images. This way you will be prepared in the case of disk failure. If the hardware has failed or digital data recovery software can not restore the files, you will simply use the latest backup to restore the files. Having own backup of files is the cheapest data recovery service.

There are many ways how to make a cheap backup of a hard drive. No expensive hardware or software is needed. You only need to be aware that the failure can happen. Digital data recovery can in many cases restore lost files, but why pay for it when you can create your own cheap recovery solution?

First DDR4 DRAM modules

Samsung Electronics has announced new generation of DDR (Double Data Rate) memory modules. DDR4 modules offer increased performance and lower consumption (up to 40%) comparing to DDR3 memory. The DDR4 chips will be manufactured using 30 nm technology. DDR4 modules will offer speeds of 1.6 Gbit/s to 3.2 Gbit/s. Taking into account that memory prices are decreasing--the cost of 1 GB of DDR3 RAM is approaching $1. The module makes use of Pseudo Open Drain (POD) technology, a new technology that has been adapted to high-performance graphic DRAM to allow DDR4 DRAM to consume half as much electric current as DDR3 when reading and writing data.

Some Facts About Deleted Files

When we delete a thing it usually doesn't exist anymore. It is deleted. We rarely expect to be able to undelete anything. But computers and all other digital equipment behaves differently. It is not possible to "normally" delete digital data. You can only change it. Of course, when you change the original data you have deleted the original information. But the data is still there, only the information was deleted.

This fact can come handy when we accidentally delete some file. The first step of deleting a file is to move it to the recycle bin. From here it can easily be restored back. But when we empty the recycle bin the file is lost. But we can still get it back because it was not deleted, it was only marked as invisible (deleted). It is possible to undelete or recover files even if they were removed from the trash can. However, this possibility lasts until some other file overwrites the original deleted file.

Because of the way how operating systems delete files many companies have problems. Whenever they would like to get rid of old computers they can not simply dump them. All the hard drives contain files. There might be sensitive data or even confidential files, passwords or credit card numbers. Therefore, before each computer leaves a company, every hard drive must be erased. To properly erase the hard drive and to actually delete all the files and to prevent data recovery, all the data on the drive must be overwritten many times. One pass is not enough because of the way how hard drive writing heads write new data on the drive. With some advanced technique it would be possible to recover once overwritten data. However, such equipment is expensive and not available to everyone. But for intelligence agencies this is not a problem, so adequate measures need to be taken.

Hard drive data recovery is possible but you need tools and knowledge. Because of many reasons computer users lose their data there are many data recovery companies. They can recover data from damaged or broken hard drives, failed digital cameras, RAID systems or any other digital media.

Use Proxy For Anonymous Browsing

You have probably already come to the situation where you wanted to visit some website but not from your computer. There are many reasons why you want to browse the internet anonymously. The main reason is to hide your IP address. When you visit some website you provide a lot of information about you and your computer to that website. From the IP address it is possible to determine not just your country but also more precise location. Although it is not easy to connect the IP address with particular person, sometimes it is simply not desired to expose your location or properties of your browser.

There is a very simple way to avoid exposing your details to the destination page. You can use a proxy service to bypass your direct connection with any website. This is a service that acts as an intermediate computer which accepts your web addresses and returns requested web pages. So the target website sees the proxy computer and not your computer or your browser. This way you are not accessing the websites directly and your IP address and other data is not exposed to the world but only to one computer. The only disadvantage of browsing this way is that the communication is a little bit slower because of the additional "element" between your computer and web server. This additional element is a computer which downloads pages and sends them to your browser. But this is the only price you will have to pay for anonymity.

There are many free proxy services. Just Google for "free proxy" and you will find many websites offering this service for free. Browsing is still pretty simple. Instead of entering the wanted web address into the address bar of the browser you enter it into address field of the proxy page and press enter or click the "go" button. This website will download web page and send it to your browser. You will get exactly the same content as you would get by browsing directly. This is not true if the server returns data according to the visitor's country. In such case you will probably get some local content. When you browse through proxy you access the target website with the IP address of the proxy website which may be hosted in a different country.

Proxy servers or websites offer some additional functions for even better protection. One of them enables you to prevent storing cookies. Cookies are some data that is stored on your computer when you visit certain pages. The second protection function is to remove JavaScript code. This code runs in your browser when the page loads. You can enable or disable these options on the same page where you enter the target address.

In most cases you can browse directly because there is no need to hide yourself. But in some cases it is better to browse anonymously and not reveal your true identity. You can also use proxy websites to access your website from other countries in order to check if right ads for that country are displayed. It is up to you to decide when to browse this way. Anyway, proxies enable us to effectively hide out location and computer data.

FM Radio - Free Music on Every Corner

Radio is probably one of the most popular free services. We can listen to it just everywhere. At home, at work, in the bus, in the car, while we walk, etc. With the term "radio" we usually mean a sound service that we can receive and is usually free, without any subscription or expensive equipment. With radio you also get free music. You can listen to it while working or you can relax and enjoy listening to your favorite band. There are many ways to get such free sound service. Each has some advantages and disadvantages but the fact is that the old FM radio as we know it is far the most widely used broadcasting service.

You can listen to radio stations that are broadcasting over internet. This service is still free, but you need access to the internet and a computer. There are also some devices (network players) that support internet broadcasting, but you still need access to the internet, either wireless (WiFi) or over local network. The advantage of internet broadcasting is that there are thousands of stations so it easy, at least in theory, to find a station that plays music according to your taste. Cable and IPTV systems also offer radio stations but this is limited to the place where you have the connection.

Satellites also offer a lot of radio stations. But to receive satellite stations you need a satellite receiver, so this type of reception is only suitable for home listening. There are also mobile satellite radio services, but in general they are not free. You have to pay a subscription. Despite the fact that satellite services are cheap and you get large coverage areas, this type of broadcasting is not suitable for general reception. Satellites do offer a huge choice of stations, but the receiving equipment is pretty complex.

Therefore, terrestrial broadcasting is the most popular platform for radio. While AM broadcasting is still used in some countries, mainly for international broadcasting, it is the FM radio that we can find it on every corner. There are many reasons for its popularity. It is free, you only need a simple and cheap receiver. Receivers are now integrated also into mobile phones, MP3 players and many other devices. The quality of FM (frequency modulation) is very high. With quality stereo reception and some high-end receiver you get superb sound quality comparable to vinyl records.

Because of many advantages of terrestrial broadcasting there are many stations interested in using this media. Of course, the radio-frequency spectrum is a limited resource and only a small fraction of the whole spectrum is allocated to broadcasting. Therefore, we can fit only a limited number of stations into this band. In addition to this, to prevent harmful interferences there are many strict rules on frequency planning which further limit the number of possible radio stations that we can receive.

But despite all the disadvantages and limitations the FM radio will be used for many years to come. Interestingly, there is still no comparable digital broadcasting system that could replace the old analog radio.

Web Hosting Facts

Web hosting is more than just putting some files on the web server. It is also a relationship between website owner and web hosting provider. The purpose of websites is to continuously offer access to web pages. Serving web pages without interruption or failures all around the clock. Of course, 100% up-time is not our goal and it would cost us a lot of money. A reasonable expectation is about 99.9% up-time. This means that on average 8 hours per year the system could be down. This is acceptable and doesn't cause much trouble to either website owner or visitors.

The things change when there are frequent malfunctions and the website is inaccessible for hours or even days. This is where we can start distinguishing good hosting from a not so good one. If the hosting provider doesn't have good support then the website owner quickly becomes frustrated and if the problems are not solved within few hours the web hosting service looses that customer. Loosing many customers means also loosing reputation. Bad reputation is the last thing a web hosting service provider wants.

The next important fact about hosting providers is the service they offer and/or advertise. To attract customers many web hosting providers promise unlimited "everything". Is this possible? Well, yes and no. Theoretically they don't limit disk size, bandwidth, number of domains, etc. The truth is that the web server is a physical machine, a computer with limited hard disk, limited processor capabilities, limited amount of memory, i.e. the computer is a limited resource. In addition to this, our web server is not hosting only our website (unless we have such hosting plan). Usually it hosts hundreds of websites. All the server resources are limited and shared between all websites hosted on this server. So you should understand properly the word "unlimited".

Another important fact about web hosting is connectivity with the internet. The connection between hosting provider and ISP should not be some bottleneck which limits how fast our pages load. The hosting provider should have a fast and reliable connection with the internet backbone. Pages that load slowly and even more slowly when the server is loaded are not visited frequently. We might loose visitors only because of poor internet connection of our web hosting provider.

Before we decide for web hosting company it is a good idea to check all key factors that contribute to fast and reliable hosting. We can contribute a lot to speed up our pages if we limit the resources that are needed to load the page. Pages without all the bells and whistles can also be useful to the visitors.