The cable guide

Cat 5e

This cable connects every device to your home network, allowing you to distribute movies, music and photos from PCs to HDTVs.

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HDMI

The current king of AV cables, HDMI carries an uncompressed 1080p video signal and up to eight channels of digital audio.

USB

The standard wire for connecting PC peripherals is also used for game-console controllers.

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Component

This three-plug analog technology can carry HD video up to 1080p, but cannot handle audio.

iPod Connector

Many home theater receivers integrate iPod docks or USB inputs that interface directly with iPods.

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S-Video

Back in the days of DVDs, S-video was the highest quality video connector you could get, but it is limited to an analog signal of 480i.

DVI

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Some PCs now have built-in AV connectors, but DVI, a video-only screen output, is still the most common way to get HD images out of a computer.

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Composite

This video cable can only carry a standard-def image, but it is common on older equipment.

SPDIF

This optical cable transmits a purely digital audio signal from components and computers to receivers.

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RCA Audio

Two-plug analog RCA jacks are still the most common way to connect audio components.

Minijack

Most commonly used for headphones, this analog stereo audio connection is also the default audio output for portable devices.

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Coaxial

Not to be confused with coaxial audio, this is the "cable" behind the cable industry. It carries both multichannel video and Internet into your home.

Coaxial Audio

Like optical SPDIF audio cables, coaxial audio cables carry pure digital audio signals from components to AV receivers.

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Speaker Wire

Great big spools of this traditional wire need to be run throughout a room to carry sound from an AV receiver to surround-sound speakers.

Computer Cooling System Solutions

Computers and Heat

A computer system is comprised of electronic components such as a central processing unit, RAM, motherboard, and more. As new computers become ever more advanced and are coaxed to work faster, more heat is produced by these electronic components. Required to compute more, modern systems require increased cooling and ventilation capabilities to move air through the unit, dissipating excess heat and keeping the components working within safe operating temperatures. Cooling and dissipation of heat, especially around the central processing unit, is always a cause for concern as the temperature of the interiors of a PC increase due to the amount of heat generated by the central processing unit. Excess heat that is not removed by sufficient cooling can negatively impact the normal functioning of the central processing unit and can cause circuits and components to become unstable. If the temperature increases beyond a certain threshold, then the heat interferes with the proper functioning of the PC and can cause serious malfunctions. Without a proper computer cooling system, the PC's electronic components may not be able to function optimally and the integral parts of what makes the computer work could even be damaged. Overheating can reduce the lifespan of computer components and peripheral units and can lead to data loss and irreparable damage. Processor types and other factors determine the safe thermal operating range, a range that varies from computer manufacturer to manufacturer.

Cooling Computer Systems

To remove excess heat from a computer system, a thermal management cooling system is used. Typically, a heat sink is employed with a computer's central processing unit to increase the heat dissipation area for more effective cooling. Heat sinks have thermal conductors that draw heat away from a component, such as a processor, and carry it into fins that provide a large enough area for heat to dissipate and sufficient cooling to take place. Active heat sinks incorporate a fan to keep the processor cool. There are two types of heat sinks: active and passive. Active heat sinks make use of power to run the cooling fan to cool down the system and allow concentrated, dedicated cooling of the processor, while passive heat sinks dissipate heat through convection. To get the best results from active cooling, quality fans with ball bearings must be chosen to give top performance, and for passive cooling to work efficiently, the machine must be placed in an area where there's a steady flow of air moving across the fins.

Cooling fans are used to blow cool air over the heat-generating components in a computer and to draw the accumulated hot air away from the area around the components, thus lowering the temperature of the air surrounding the components while allowing more heat to be radiated out of the case.

Using Cooling Fans in Computers

Air-cooling with fans is one of the most widely practiced ways of dissipating heat in computers. Fans are not only easy to install and maintain, but are also an effective way to remove heat from components and bring in cooler air, thus maintaining a constant optimal temperature for operation. Fan sizes, types, and placements play an important role in the efficient dissipation of heat. The most common sizes for computer fans, which are typically square devices, include 60mm, 80mm, 92mm, and 120mm. Some of the types of cooling fans often installed in computers include:

• CPU fans, which are used in conjunction with heat sinks to prevent overheating of the components in central processing units.
• Case fans, which cool the surrounding area by circulating fresh air through the case by drawing out hot air, drawing in cooler air, or both.
• Hard drive fans, which are often used in systems with heat-production challenges from a lot of hard drive usage.

There are many types of solutions that can maintain the high reliability of a computer's electronic components. However, leaving the decision about a computer cooling system until the end of the design process can prove to be costly in terms of larger or more expensive solutions. Instead, consider all your temperature regulation options at the initial stages of development to reduce costs while improving design layout and establishing high reliability.

Keep Your PC from Overheating

Apart from choosing the right cooling devices for your PC, you can also increase the lifespan of the components, avoid overheating, and improve reliability by taking measures such as maintaining a clean, dust-free operating environment for your computer.

The inside of a PC should be cleaned thoroughly at least once every six months, as dust build-up can lead to heating problems. In fact, dust accumulation is one of the main causes of premature system malfunctions and reliability problems. Dust acts as an insulation blanket that prevents heat from escaping. This can cause the system to overheat. Make sure you clean the inside of the CPU, including the fans on the top of the CPU, the filters of fans, and the fan located on top of the power supply.

Computer Cooling System Solutions from NMB

Drawing on our extensive experience in the manufacturing of bearings, one of the main components a cooling fanrelies on to work effectively, NMB manufacturers reliable, smoothly operating, and long lasting products to keep your computer system cool.

The future is coming faster....here's why...????

Moore’s Law / Quantum Computing

Currently, the growth in the rate of our technological advance is spearheaded by advances in computer chip technology. Through the tracking of this growth, it has been pronounced ‘Moore’s Law’. At some point in the next decade, the computer chip will reach the maximum level it can advance. But that does not mean that the exponential growth of technological advances will end. Another technology will simply take over the role of spearheading the growth. At around the year 2020, Quantum Computing will take over from the computer chip, and will be far far more advanced. Quantum Computing could even rise the rate of growth higher than the exponential rate.

We will show you what is possible

I would much prefer to have my smartphone, rather than a hover board; a smartphone of which was not even predicted in the Back to the Future Movie. The point is, the latest generation of futurists, should not be prejudged by what previous generations failed to predict. The predictions of the future that are being made now, are far more educated, and based on evidence based trends.With the understanding of exponential growth, people tend to look at future possibilities with much more of an open mind. Predictions of the future that were made in the 20th century, were largely made without consideration of trends and what society will want and need as their priority. Flying cars are not needed, and will not be needed for a very long time, if ever. It is not a priority to build them. When people were predicting flying cars, they didn’t even know what would make them fly, or what would even power them.

This website displays what is possible, and what dates in the future those possibilities will most likely become reality. Nothing is certain. But if exponential growth continues, everything will be possible.

How memory works?

The Central Processing Unit: (CPU), Buses, Ports and controllers, ROM; Main Memory (RAM); Input Devices; Output Devices; Secondary Storage; floppy disks, hard disk, CD-ROM

Figure 0: Inside The Computer

This part of the reading will examine the CPU, Buses, Controllers, and Main Memory. Other sections will examine input devices, output devices, and secondary memory.

The Central Processing Unit (CPU)

Figure 1: The Central Processing Unit

The computer does its primary work in a part of the machine we cannot see, a control center that converts data input to information output. This control center, called the central processing unit (CPU), is a highly complex, extensive set of electronic circuitry that executes stored program instructions. All computers, large and small, must have a central processing unit. As Figure 1 shows, the central processing unit consists of two parts: The control unit and the arithmetic/logic unit. Each part has a specific function.

Before we discuss the control unit and the arithmetic/logic unit in detail, we need to consider data storage and its relationship to the central processing unit. Computers use two types of storage: Primary storage and secondary storage. The CPU interacts closely with primary storage, or main memory, referring to it for both instructions and data. For this reason this part of the reading will discuss memory in the context of the central processing unit. Technically, however, memory is not part of the CPU.

Recall that a computer's memory holds data only temporarily, at the time the computer is executing a program. Secondary storage holds permanent or semi-permanent data on some external magnetic or optical medium. The diskettes and CD-ROM disks that you have seen with personal computers are secondary storage devices, as are hard disks. Since the physical attributes of secondary storage devices determine the way data is organized on them, we will discuss secondary storage and data organization together in another part of our on-line readings.

Now let us consider the components of the central processing unit.

The Control Unit
The control unit of the CPU contains circuitry that uses electrical signals to direct the entire computer system to carry out, or execute, stored program instructions. Like an orchestra leader, the control unit does not execute program instructions; rather, it directs other parts of the system to do so. The control unit must communicate with both the arithmetic/logic unit and memory.

The Arithmetic/Logic Unit
The arithmetic/logic unit (ALU) contains the electronic circuitry that executes all arithmetic and logical operations.

The arithmetic/logic unit can perform four kinds of arithmetic operations, or mathematical calculations: addition, subtraction, multiplication, and division. As its name implies, the arithmetic/logic unit also performs logical operations. A logical operation is usually a comparison. The unit can compare numbers, letters, or special characters. The computer can then take action based on the result of the comparison. This is a very important capability. It is by comparing that a computer is able to tell, for instance, whether there are unfilled seats on airplanes, whether charge- card customers have exceeded their credit limits, and whether one candidate for Congress has more votes than another.

Logical operations can test for three conditions:

• Equal-to condition. In a test for this condition, the arithmetic/logic unit compares two values to determine if they are equal. For example: If the number of tickets sold equals the number of seats in the auditorium, then the concert is declared sold out. 
• Less-than condition. To test for this condition, the computer compares values to determine if one is less than another. For example: If the number of speeding tickets on a driver's record is less than three, then insurance rates are $425; otherwise, the rates are $500. 
• Greater-than condition. In this type of comparison, the computer determines if one value is greater than another. For example: If the hours a person worked this week are greater than 40, then multiply every extra hour by 1.5 times the usual hourly wage to compute overtime pay.

A computer can simultaneously test for more than one condition. In fact, a logic unit can usually discern six logical relationships: equal to, less than, greater than, less than or equal to, greater than or equal to, and not equal.

The symbols that let you define the type of comparison you want the computer to perform are called relational operators. The most common relational operators are the equal sign(=), the less-than symbol(<), and the greater-than symbol(>).

• Registers: Temporary Storage Areas
  Registers are temporary storage areas for instructions or data. They are not a part of memory; rather they are special additional storage locations that offer the advantage of speed. Registers work under the direction of the control unit to accept, hold, and transfer instructions or data and perform arithmetic or logical comparisons at high speed. The control unit uses a data storage register the way a store owner uses a cash register-as a temporary, convenient place to store what is used in transactions.
  
  Computers usually assign special roles to certain registers, including these registers:
  
  • An accumulator, which collects the result of computations.
  • An address register, which keeps track of where a given instruction or piece of data is stored in memory. Each storage location in memory is identified by an address, just as each house on a street has an address.
  • A storage register, which temporarily holds data taken from or about to be sent to memory.
  • A general-purpose register, which is used for several functions.
• Memory and Storage 
  Memory is also known as primary storage, primary memory, main storage, internal storage, main memory, and RAM (Random Access Memory); all these terms are used interchangeably by people in computer circles. Memory is the part of the computer that holds data and instructions for processing. Although closely associated with the central processing unit, memory is separate from it. Memory stores program instructions or data for only as long as the program they pertain to is in operation. Keeping these items in memory when the program is not running is not feasible for three reasons:
  
  • Most types of memory only store items while the computer is turned on; data is destroyed when the machine is turned off.
  • If more than one program is running at once (often the case on large computers and sometimes on small computers), a single program can not lay exclusive claim to memory.
  • There may not be room in memory to hold the processed data.
  
  How do data and instructions get from an input device into memory? The control unit sends them. Likewise, when the time is right, the control unit sends these items from memory to the arithmetic/logic unit, where an arithmetic operation or logical operation is performed. After being processed, the information is sent to memory, where it is hold until it is ready to he released to an output unit.
  
  The chief characteristic of memory is that it allows very fast access to instructions and data, no matter where the items are within it. We will discuss the physical components of memory-memory chips-later in this chapter.
  To see how registers, memory, and second storage all work together, let us use the analogy of making a salad. In our kitchen we have:
  
  • a refrigerator where we store our vegetables for the salad;
  • a counter where we place all of our veggies before putting them on the cutting board for chopping;
  • a cutting board on the counter where we chop the vegetables;
  • a recipe that details what veggies to chop;
  • the corners of the cutting board are kept free for partially chopped piles of veggies that we intend to chop more or to mix with other partially chopped veggies.
  • a bowl on the counter where we mix and store the salad;
  • space in the refrigerator to put the mixed salad after it is made.
  The process of making the salad is then: bring the veggies from the fridge to the counter top; place some veggies on the chopping board according to the recipe; chop the veggies, possibly storing some partially chopped veggies temporarily on the corners of the cutting board; place all the veggies in the bowl to either put back in the fridge or put directly on the dinner table.The refrigerator is the equivalent of secondary (disk) storage. It can store high volumes of veggies for long periods of time. The counter top is the equivalent of the computer's motherboard - everything is done on the counter (inside the computer). The cutting board is the ALU - the work gets done there. The recipe is the control unit - it tells you what to do on the cutting board (ALU). Space on the counter top is the equivalent of RAM memory - all veggies must be brought from the fridge and placed on the counter top for fast access. Note that the counter top (RAM) is faster to access than the fridge (disk), but can not hold as much, and can not hold it for long periods of time. The corners of the cutting board where we temporarily store partially chopped veggies are equivalent to the registers. The corners of the cutting board are very fast to access for chopping, but can not hold much. The salad bowl is like a temporary register, it is for storing the salad waiting to take back to the fridge (putting data back on a disk) or for taking to the dinner table (outputting the data to an output device).
  
  Now for a more technical example. let us look at how a payroll program uses all three types of storage. Suppose the program calculates the salary of an employee. The data representing the hours worked and the data for the rate of pay are ready in their respective registers. Other data related to the salary calculation-overtime hours, bonuses, deductions, and so forth-is waiting nearby in memory. The data for other employees is available in secondary storage. As the CPU finishes calculations about one employee, the data about the next employee is brought from secondary storage into memory and eventually into the registers.
  The following table summarizes the characteristics of the various kinds of data storage in the storage hierarchy.
  

  Storage	Speed	Capacity	Relative Cost ($)	Permanent?
  Registers	Fastest	Lowest	Highest	No
  RAM	Very Fast	Low/Moderate	High	No
  Floppy Disk	Very Slow	Low	Low	Yes
  Hard Disk	Moderate	Very High	Very Low	Yes

  Modern computers are designed with this hierarchy due to the characteristics listed in the table. It has been the cheapest way to get the functionality. However, as RAM becomes cheaper, faster, and even permanent, we may see disks disappear as an internal storage device. Removable disks, like Zip disks or CDs (we describe these in detail in the online reading on storage devices) will probably remain in use longer as a means to physically transfer large volumes of data into the computer. However, even this use of disks will probably be supplanted by the Internet as the major (and eventually only) way of transferring data. Floppy disks drives are already disappearing: the new IMac Macintosh from Apple does not come with one. Within the next five years most new computer designs will only include floppy drives as an extra for people with old floppy disks that they must use.For more detail on the computer's memory hierarchy, see the How Stuff Works pages on computer memory.. This is optional reading.
• How the CPU Executes Program Instructions
  Let us examine the way the central processing unit, in association with memory, executes a computer program. We will be looking at how just one instruction in the program is executed. In fact, most computers today can execute only one instruction at a time, though they execute it very quickly. Many personal computers can execute instructions in less than one-millionth of a second, whereas those speed demons known as supercomputers can execute instructions in less than one-billionth of a second.
  
  

  Figure 2: The Machine Cycle

  Before an instruction can be executed, program instructions and data must be placed into memory from an input device or a secondary storage device (the process is further complicated by the fact that, as we noted earlier, the data will probably make a temporary stop in a register). As Figure 2 shows, once the necessary data and instruction are in memory, the central processing unit performs the following four steps for each instruction:
  
  1. The control unit fetches (gets) the instruction from memory.
  2. The control unit decodes the instruction (decides what it means) and directs that the necessary data be moved from memory to the arithmetic/logic unit. These first two steps together are called instruction time, or I-time.
  3. The arithmetic/logic unit executes the arithmetic or logical instruction. That is, the ALU is given control and performs the actual operation on the data.
  4. Thc arithmetic/logic unit stores the result of this operation in memory or in a register. Steps 3 and 4 together are called execution time, or E-time.
  
  The control unit eventually directs memory to release the result to an output device or a secondary storage device. The combination of I-time and E-time is called the machine cycle. Figure 3 shows an instruction going through the machine cycle.
  
  Each central processing unit has an internal clock that produces pulses at a fixed rate to synchronize all computer operations. A single machine-cycle instruction may be made up of a substantial number of sub-instructions, each of which must take at least one clock cycle. Each type of central processing unit is designed to understand a specific group of instructions called the instruction set. Just as there are many different languages that people understand, so each different type of CPU has an instruction set it understands. Therefore, one CPU-such as the one for a Compaq personal computer-cannot understand the instruction set from another CPU-say, for a Macintosh.

  Figure 3: The Machine Cycle in Action

  It is one thing to have instructions and data somewhere in memory and quite another for the control unit to be able to find them. How does it do this?
  
  

  Figure 4: Memory Addresses Like Mailboxes

  The location in memory for each instruction and each piece of data is identified by an address. That is, each location has an address number, like the mailboxes in front of an apartment house. And, like the mailboxes, the address numbers of the locations remain the same, but the contents (instructions and data) of the locations may change. That is, new instructions or new data may be placed in the locations when the old contents no longer need to be stored in memory. Unlike a mailbox, however, a memory location can hold only a fixed amount of data; an address can hold only a fixed number of bytes - often two bytes in a modern computer.
  
  Figure 4 shows how a program manipulates data in memory. A payroll program, for example, may give instructions to put the rate of pay in location 3 and the number of hours worked in location 6. To compute the employee's salary, then, instructions tell the computer to multiply the data in location 3 by the data in location 6 and move the result to location 8. The choice of locations is arbitrary - any locations that are not already spoken for can be used. Programmers using programming languages, however, do not have to worry about the actual address numbers, because each data address is referred to by a name. The name is called a symbolic address. In this example, the symbolic address names are Rate, Hours, and Salary.

6 worst health problems common with computer use

1. Musculoskeletal problems:

Muscle soreness and muscle fatigue are the most common complaints of regular computer users. Back pain, chest pain, pain or numbness in arms, shoulder and feet top the list. These types of problems mainly occur because your posture while using the computer is not correct. Either you are sitting on an uncomfortable chair or your workstation is not supportive of correct posture. Read more about causes of muscle pain.

Practical tips

• Adjust your chair and desk such that your screen is either at your eye level or lower. Sit with your back straight and legs perpendicular to the floor with feet resting flat on the floor. Your elbows should rest at the sides.
• Take mini breaks from work and stretch a bit or go for a short walk. Here are a few more tips for correcting ergonomics at work.

2. Repetitive stress injury

Pain in the neck, shoulder, or anywhere from the shoulder to fingers may indicate repetitive stress injury. When you use your muscles in an awkward position, you may experience stiffness, pain or swelling in that area. For example, twisting the wrist to use the mouse or specific typing technique that causes stretching of fingers or pressure on the wrist can turn really painful. One of the disorders that affect the fingers and wrist is carpal tunnel syndrome.  

Practical Tips:

• Adjust the mouse besides the keyboard. Move your entire arm, while moving the mouse. Don’t just move your wrist by fixing it at one position. Typing should be gentle. Do not fix your wrists in a certain position while typing.
• Relax your arms or stretch when you are not typing or using the mouse.

3. Vision problems

Bright light and bad glare or flickering image can strain your eyes. Constantly focusing on the screen without blinking can cause dry eyes. Computer vision syndrome is another problem that you may suffer from. Here are some natural remedies for improving eye sight.

Practical tips

• Adjust the contrast and brightness such that your eyes are not strained. You can tilt your screen to avoid glare.
• Maintain a proper distance from the screen. Look away from the screen intermittently. Don’t forget to blink.

4. Headache

Because of increased muscle tension or pain in the neck at the base of the skull, headache is common problem with computer use. Many a times, prolonged use can affect eye power which needs vision correction. This can also result in headache. Here are more reasonswhy you should take your headache seriously.

Practical tips

• Get your eye power tested if headache is a common problem with computer use. Here are some tests that you might to check your eye sight.
• Keep your neck straight when in front of the computer. Constantly looking down or stretching the neck sideways can also cause pain. Take breaks in between and circle your neck a bit to release the strain. Read more about tips to prevent headache after using computer.

5. Obesity

Studies have shown that prolonged use of computers, especially in children, is the major contributing factor of sedentary lifestyle and childhood obesity. Read more about the reason why childhood obesity is on the rise.

Practical tips:

• Set limits for your children if they insist to playing computer games non-stop.
• Encourage your children to play outdoor games or to take up a hobby. Involve them in extra-curricular activities
• Adults who work for 7-8 hours should avoid spending time on computer after reaching home. Your body and mind both need to relax. Join a gym or go for evening jog and stay physically active.

6. Stress disorders

Technology has a huge impact on our behaviour and emotions. Prolonged computer use along with other factors like poor health, work pressure and job environment can make you susceptible to stress. Moreover, the longer you uphold the stress, the more susceptible you become to other health issues mentioned above. It can also lead to loss of concentration, dizziness and weariness.

Practical tips:

• Be proactive and take necessary measures to beat stress before it affects your health. Try these natural remedies to beat stress. Also, take a look at these effective yoga poses that can beat stress and laughter yoga to beat stress,