Archive for the ‘BASIC’ Category

How Sound Cards Work


Computer Hardware Image Gallery

Computer Hardware Image Gallery

A sound card allows a computer to create and record real, high-quality sound.

Before the invention of the sound card, a PC could make one sound – a beep. Although the computer could change the beep’s frequency and duration, it couldn’t change the volume or create other sounds.

At first, the beep acted primarily as a signal or a warning. Later, developers created music for the earliest PC games using beeps of different pitches and lengths. This music was not particularly realistic — you can hear samples from some of these soundtracks atCrossfire Designs.

 

Fortunately, computers’ sound capabilities increased greatly in the 1980s, when several manufacturers introduced add-on cards dedicated to controllingsound. Now, a computer with a sound card can do far more than just beep. It can produce 3-D audio for games or surround sound playback for DVDs. It can also capture and record sound from external sources.

In this article, you’ll learn how a sound card allows a computer to create and record real, high-quality sound.

 

A sound card must translate between sound waves and bits and bytes.

Analog vs. Digital

Sounds and computer data are fundamentally different. Sounds are analog – they are made of waves that travel through matter. People hear sounds when these waves physically vibrate their eardrums. Computers, however, communicate digitally, using electrical impulses that represent 0s and 1s. Like agraphics card, a sound card translates between a computer’s digital information and the outside world’s analog information.

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Sound is made of waves that travel through a medium, such as air or water.

The most basic sound card is a printed circuit board that uses four components to translate analog and digital information:

  • An analog-to-digital converter (ADC)
  • digital-to-analog converter (DAC)
  • An ISA or PCI interface to connect the card to the motherboard
  • Input and output connections for a microphone and speakers

Instead of separate ADCs and DACs, some sound cards use a coder/decoder chip, also called a CODEC, which performs both functions.

In the next section, we’ll explore the analog-to-digital and digital-to-analog conversions that take place on the sound card.

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How Laptops Work


How Laptops Work

laptop-9-laptop-internal

Laptop Image Gallery

The i­nside of an IBM ThinkPad

In a way, the skyrocketing popularity of laptop computers is ironic. They’re completely portable, and they use less power and make less noise than desktop models. But, they’re often a little slower and have less graphics and soundprocessing power, although these differences can be too small for most users to notice.

Laptops are also more expensive than desktops. The price gap is closing, though — laptop prices are falling faster than desktop prices, and laptop PCs actually outsold desktop models for the first time in May of 2005 [Source: Windows IT Pro].

How can all the equipment found in a desktop tower fit into such a small package? And how can laptops be efficient enough to run on battery power alone? In this article, you’ll discover the answers to these and other questions about laptops.

Overall, lap­top and desktop computers are very similar. They have the same basic hardware, software andoperating systems. The primary difference is how their components fit together.­

A desktop computer includes a motherboard, video card, hard drive and other components in a large case. The monitor, keyboard, and other peripherals connect wirelessly or with cables. Whether the case sits vertically or horizontally, it has lots of space for add-in cards, cables and air circulation.

A laptop, however, is much smaller and lighter than even the most compact PC tower. Its screen is an integrated part of the unit, as is its keyboard. Instead of a spacious case with lots of room for air circulation, a laptop uses a small, flat design in which all the pieces fit together snugly.

Because of this fundamental design difference and because of a laptop’s inherent portability, components have to:

  • Fit into a compact space
  • Conserve power
  • Produce less heat than desktop components

Often, these differences make the components more expensive, which can contribute to higher laptop prices. In the following sections, we’ll examine how laptops handle these differences.

An IBM ThinkPad’s processor

Laptop Processors

The microprocessor, or CPU, works with the operating system to control the computer. It essentially acts as the computer’s brain. The CPU produces a lot of heat, so adesktop computer uses circulating air, a fan and a heat sink — a system of plates, channels and radiator fins used to draw heat off of the processor — to cool off. Since a laptop has far less room for each of these cooling methods, its CPU usually:

  • Runs at a lower voltage and clock speed — This reduces heat output and power consumption but slows the processor down. Most laptops also run at a higher voltage and clock speed when plugged in, and at lower settings when using the battery.
  • Mounts to the motherboard without using pins — Pins and sockets take up a lot of room in desktop PCs. Some motherboard processors mount directly to the motherboard without the use of a socket. Others use a Micro-FCBGA (Flip Chip Ball Grid Array), which uses balls instead of pins. These designs save space, but in some cases mean that the processor cannot be removed from the motherboard for replacement or upgrading.
  • Has a sleep or slow-down mode — The computer and the operating system work together to reduce the CPU speed when the computer is not in use or when the processor does not need to run as quickly. The Apple G4 processor also prioritizes data to minimize battery drain.

 

Some laptops use desktop CPUs that are set to run at lower clock speeds. Although this can improve performance, these laptops typically run much hotter and have a significantly reduced battery life.

laptop-2-heatsink

A laptop heat sink and fan

Laptops usually have small fans, heat sinks, heat spreaders or heat pipes to help dissipate the heat from the CPU. Some higher end laptop models reduce heat even further with liquid coolant kept in channels alongside the heat pipe. Also, most laptop CPUs are near the edge of the unit. This allows the fan to move the heat directly to the outside instead of across other components.

 

Laptop Memory and Storage

A laptop’s memory can make up for some of the reduced performance that comes from a slower processor. Some laptops have cache memory on or very near the CPU, allowing it to access data more quickly. Some also have larger busses, allowing data to move between the processor, motherboard and memory more quickly.

Lapto­ps often use smaller memory modules to save space. Memory types used in laptops include:

  • Small Outline Dual Inline Memory Module (SODIMM)
  • Dual Data Rate Synchronous RAM (DDR SDRAM)
  • Single data rate Synchronous RAM (SDRAM)
  • Proprietary memory modules

Some laptops have upgradeable memory and feature removable panels for easy access to the memory modules.

 

Like a desktop, a laptop has an internal hard disk drive, which stores the operating system, applications and data files. However, laptops generally have less disk space than desktops. A laptop hard drive is also physically smaller than that of a desktop. In addition, most laptop hard drives spin more slowly than desktop hard drives, reducing both heat and power consumption.

Desktop computers have multiple bays for installing additional drives, such as CD and DVD ROM drives. However, space in a laptop is in much shorter supply. Many laptops use a modular design, allowing a variety of drives to fit in the same bay. These drives come in three different designations:

  • Hot swappable – The computer can stay on while changing the drive.
  • Warm swappable – The computer can stay on while changing the drive, but the corresponding bus (the path the drive uses to send data to the CPU) must be inactive.
  • Cold swappable – The computer must be off during the swap.

In some cases, these drive bays are not just limited to drives but will also accept extra batteries.

Next, we’ll look at the video processing and display capabilities of a laptop.

 

A laptop GPU

Laptop Screen, Graphics and Sound

graphics processing unit(GPU) is a microprocessor that handles the calculations necessary for 3-D graphicsrendering. Like a CPU, a GPU produces a lot of heat. Most laptops have graphics capability built into the motherboard or have smaller graphics cards with a GPU designed specifically for laptop use. GPU manufacturers ATI andnVidia both make GPUs specifically for laptops. Laptops frequently share memory between the CPU and the GPU, saving space and reducing power consumption.

Many people don’t notice a laptop’s reduced graphics performance. Laptops have plenty of processing power for Web surfing and productivity applications. However, they may struggle with the latest 3-D games. A few specialty laptops, designed for gaming enthusiasts, include more powerful GPUs and additional video memory.

A laptop displays its graphics on a liquid crystal display (LCD) screen. Most screens measure between 12 and 17 inches, and the size of the screen affects the overall size of the laptop. In addition, laptop screens can be:

  • Black-and-white (16 grayscale) or color (65,536 colors)
  • Active or passive matrix
  • Reflective or backlit

Active matrix displays have sharper images and are easier to read, and backlit screens are better for low-level lighting conditions.

Most laptops also have sound cards or integrated sound processing on the motherboard as well as small, built-in speakers. However, there is generally not enough space inside a laptop for a top-of-the-line sound card or a high-quality speaker. Gaming enthusiasts and audiophiles can supplement their laptops’ sound capabilities with external sound controllers, which use USB or FireWireports to connect to the laptop.

Laptop Batteries

Laptops ­and desktops both run on electricity. Both have small batteries to maintain the real-time clock and, in some cases, CMOS RAM. However, unlike adesktop computer, a laptop is portable and can run on batteries alone.

Nickel-Cadmium (NiCad) batteries were the first type of battery commonly used in laptop computers, and older laptops sometimes still use them. They have a life of roughly two hours between charges, but this life decreases with each charge based on thememory effect. Gas bubbles form in the cell plates, reducing the total amount of available cell space for recharge. The only way around this is to discharge the battery completely before recharging it. The other drawback of NiCad is that if the battery charges too long, it can explode.

Nickel-Metal Hydride (NiMH) batteries are the bridge between NiCad and the newer Lithium-Ion (LiIon) batteries. They last longer between charges than NiCad but overall have a shorter total lifespan. They suffer from the memory effect, but to a lesser extent than NiCad batteries.

LiIon batteries are the current standard for laptop computers. They are light and have long life spans. They do not suffer from the memory effect, can be charged randomly, and won’t overheat if overcharged. They are also thinner than any other battery available for laptops, making them ideal for the new ultra-thin notebooks. LiIon batteries can last for anything from about 950 up to 1200 charges.

Many laptops with LiIon batteries claim to have a 5-hour battery life, but this measurement can vary greatly depending on how the computer is used. The hard drive, other disk drives and LCD display all use substantial battery power. Even maintaining wireless Internet connectivity requires some battery power. Many laptop computer models have power management software to extend the battery life or conserve battery power when the battery is low.

 

Whitebooks

Many people build custom PCs for themselves or customers. These home-made computers, calledwhiteboxes, represent a significant portion of the computer market. Some people also modify their computers for cosmetics or performance. This is called modding. But what about building or modding a laptop?­

A­ modded or homemade laptop is called a whitebook. Whitebooks represent about 5 percent of the notebook market right now, and this number is slowly rising. The industry has done a pretty good job of keeping end users out of laptops. They’ve made it difficult to open, modify and get parts for a laptop. In addition, opening the laptop chassis voids the manufacturer’s warranty in most cases.

It is still difficult to find parts to build a laptop from the ground up, but vendors like ASUS and ECS allow some customers to order blank laptop shells. They are especially open to resellers who build whitebooks and sell them to customers. In addition, people can mod or upgrade what came with the shell. Companies like TechStyle have made a business of it.

A laptop shell consists of:

  • Chassis
  • Motherboard
  • Optical drive
  • Display
  • Keyboard
  • Graphics Card

This means that anyone wanting to build a whitebook must find:

  • Microprocessor
  • RAM
  • Wireless card

At this point, there are no real standards for the form factor (shape and design) of laptop parts. Processors designed for laptops are available for sale, but finding a motherboard for those chips is a different story. Hard drives are pretty standard, and SODIMM system memory is easy to come by, but other parts may take some digging.

Next, we’ll look at the history of laptop computers.

 

Laptop History

In the 1970s, Alan Kay of the Xerox Palo Alto Research Center had a vision for a wireless portable computer roughly the size of a notebook. He called it theDynabook. Kay’s Dynabook never got past sketches and a cardboard model, but it set the wheels in motion for the development of a truly portable computer.

I­n 1979, William Moggridge of Grid Systems Corporation created the first functioning portable computer:The Grid Compass Computer 1109. It had 340 kilobytes of bubble memory, a die-cast magnesium case and a folding electroluminescent graphics display screen. NASA bought a handful of them at $800 apiece for use in the space program.

Other companies, like Gavilan Computer and Apple, introduced other portable computers in following years. The first commercially viable machine, however, was the IBM PC Convertible, introduced in 1986. The PC Convertible featured:

  • An 8088 microprocessor
  • 256 kilobytes of memory
  • Two 3.5-inch (8.9-cm) floppy drives
  • An LCD display
  • Parallel and serial printer ports
  • Space for an internal modem
  • A software suite including basic word processing, appointment calendar, telephone/address book, and calculator software

Weighing in at a hefty 12 lbs (5.4 kg), the PC Convertible sold for $3,500. It was the first portable computer with the clamshell design used in today’s laptops. The success of the PC Convertible was the catalyst for competitors like Compaq and Toshiba to switch to the clamshell design in their portable computers. And so began the era of the laptop computer.

What are system resources, and why do I run out of them?


A memory chip, like the one above, contains an area for system resources.

In many cases, an “out of memory” message is misleading, since your whole system really did not run out of memory. Instead, certain areas of memory (Microsoft calls “heaps”) used by Windows have run low on space.

Windows maintains an area of memory for operating system resources. The maximum size of this area is 128K, in two 64K areas. Windows 95/98 uses this area of memory to store fonts, bitmaps, drop-down menu lists and other on-screen information used by each application.

When any program begins running, it uses up some space in the “system resources” area in memory. But, as you exit, some programs do not give back system resources they were temporarily using. Eventually the system will crash as it runs out of memory. The crash happens sometimes if you start and close many programs, even the same ones, without a periodic reboot. This is what Microsoftcalls a resource leak or memory leak.

When you tell your system to exit a program, the program is supposed to give back the resources (memory) it was using. But, because programs are written by humans, mistakes can happen and the program may not give back all to the operating system. This failing to “give back” is the “memory leak,” eventually leading to a message that your computer is low on resources. Memory leaks can also be caused by programs that automatically load every time you boot your Windows system. In Windows 95/98 you can see the list of active programs via the usual Ctrl-Alt-Del sequence. The Windows Startup folder contains programs that launch every time your system boots. In Windows 98, set the folder contents with MSCONFIG. In Windows 95, click the right mouse button on the Task Bar, click Properties, click Start Menu Programs, click Advanced and look for the Startup folder in the left pane.

The system resources problem is something you might have to live with until the misbehaving application is found. If you are sure a certain application is causing the problem, be sure to contact the software vendor.­

You can keep track of your system resources via the handy tool at Start >> Programs >> Accessories >> System Tools >> Resource Meter. If you do not have a copy, you can download it at UtilMind Solutions. The resource meter adds the “fuel gauge” to your Windows task bar, to help you keep track of your system’s resources. As the bar graph gauge turns from green to yellow, then the dreaded red, you know you have a problem! But you need to remember that the resource meter also consumes what you are trying to conserve: system resources.

 

WHAT’S INSIDE: COMPUTER HARDWARE


Computer Hardware Pictures

Computer Hardware Pictures

Some people love to take things apart to see how they work. But just because you can take a gadget apart doesn’t mean you can put it back together again. Even a successful rebuild doesn’t guarantee the device will still work. It’s best to leave some deconstruction projects to the professionals. When the device in question is a computer, this warning is particularly important.

Computers can be complicated, delicate and even dangerous. But that doesn’t stop us from wanting to know what’s actually inside one. That’s why we here at HowStuffWorks have taken it upon ourselves to dismantle a perfectly innocent computer in the name of science. We chose an IBM ­laptop computer, which not only has all the standard components you’d find in most computers, but also arranges them together into a very compact configuration.

Keep in mind that while desktop computers are larger than laptops, the actual components inside the computers are pretty much the same. The parts might look a bit different — there’s no need to pack them in so tightly — but they fulfill the same functions as the parts in a laptop computer. One other big difference is that many desktop computers allow users to swap out cards and components through computer card slots while many laptop computers have integrated cards that users can’t swap out.

We’ve divided up the components into two main categories: the brains and the guts. The brains of the computer include all the elements that allow the computer to process data. The guts include all the other elements that make computers useful, but aren’t directly involved in computing information.

We’ll begin with a little laptop neurosurgery. Join us in the next section as we take a closer look at the brains of a computer.

The Computer Brain

The base of operations for the brains of a computer is themotherboard. The motherboard serves as a literal foundation for many of the other elements inside your computer. It’s a large printed circuit board. The motherboard provides the connections and sockets that let other components communicate with each other. Motherboards come in different shapes and sizes — a motherboard in a laptop computer might not look like one from a desktop PC.

The computer brain is a microprocessor called the central processing unit (CPU). The CPU is a chip containing millions of tiny transistors. It’s the CPU’s job to perform the calculations necessary to make the computer work — the transistors in the CPU manipulate the data. You can think of a CPU as the decision maker.

Another critical component in computers is memory. The two most important kinds of memory are read-only memory (ROM) andrandom access memory (RAM). Computers can read data stored inROM, but can’t write new data to it. With RAM, computers can read from and write to that memory. Without computer memory, every calculation on a computer would be stateless. That means there’d be no way to preserve information from one moment to the next and every process would start on a clean slate. That’s not useful if you want to create complex programs.

Many desktop PCs have the capacity for additional RAM. The user simply has to open the computer and plug RAM chips into the appropriate sockets on the motherboard. But other computers are sealed systems — you aren’t meant to open them and make changes so you’re pretty much stuck with what you’ve got.

A chip called the Basic Input/Output System (BIOS) works closely with the CPU. BIOS is a specific kind of ROM. If you think of the CPU as the brain of the computer, then you might consider BIOS to be the spine. It’s the job of BIOS to handle interactions between the software running on a computer and the machine’s hardware components.

The motherboard, CPU, ROM, RAM and BIOS handle most of the heavy lifting for computer processes. They’re in charge of allocating resources to applications so that they run smoothly. They also accept input from devices like keyboardsmice and other computer accessories.

There are plenty of other components inside your computer. Let’s get into the guts of a computer in the next section.

Launch Video

Other Computer Parts

So what else is inside your computer? We can divide up the guts of a computer into five categories:

  • Power supplies and batteries
  • Drives
  • Modems and Wi-Fi cards
  • Sound and graphics cards
  • Cooling systems

The power supply component provides a supply of electricitythroughout the rest of the computer. When you plug your computer into a power socket, electricity flows from the cord into a shielded box containing a transformer. The transformer‘s job is to convert the incoming electricity into the proper voltage for each part of the machine that needs electricity. If you’re using a laptop, some of that power goes to the laptop’s battery to charge it. When unplugged, a laptop has to rely on the charge inside the battery for its power needs.

Computers have a small battery inside them that’s always on, even when you power down the rest of the computer. This battery helps preserve data stored in a special chip in charge of maintaining information about your computer’s hardware. It also powers a clock, which is why your computer should keep time accurately even if you turn it off or unplug it.

The drives in a computer are the devices that let you store and recall data and applications. Most computers have a hard drive — either a series of thin platters that store information using magnetic recordings or a solid state flash hard drive with no moving parts. In either case, the hard drive allows you to store information and applications directly to your computer.

Older computers used floppy disk drives. Newer computers have optical storage drives like CD-ROM orDVD-ROM drives. These drives allow you to use media storage devices like compact discs or DVDs with your computer.

Modems are machines that let computers communicate with other computing systems. Modems are closely related to wireless cards, which are radio transceivers that can send and receive data through a specific frequency of radio waves.

Sound and graphics cards are pretty self-explanatory. They give your computer the ability to display graphics or play sounds and music. Not all cards are the same — some support more software formats than others. Graphics cards in particular come in a wide variety of specs.

Copyright 2008 HowStuffWorks

Cooling systems typically includeheat sinks and fans. Overheating can be a serious problem with computers, causing performance to suffer to the point of a system failure in some cases. Heat sinks absorb heat and move it away from critical components. Fans give computers a way to exhaust heat externally. Some computers have more advanced liquid-cooling systems. A water-cooling syst­em uses tubes of flowing water to absorb heat and move it away from critical components.

There you have it. That covers the major elements that are inside a typical computer. Now you don’t have to take one apart and look at it yourself. And we get to find out if this computer will still work once we put it back together.

 

 

Is it better to turn my computer off or leave it on all the time?


Computer Hardware Image Gallery

Computer Hardware Image Gallery

This is one of those questions where there is no single right answer. In other words, it depends on how you use your computer.

There are at least three situations that force you to leave your computer on 24 hours a day:

  • You are on a network, and the network administrators back up files and/or upgrade software over the network at night. If that is the case, and you want your machine backed up or upgraded, then you need to leave it on all the time.
  • You are using your machine as some sort of server. For example, HowStuffWorks has a machine that creates the images for the How Webcams Work article. It needs to be on 24 hours a day. If your machine acts as a file server, print server, Web server, etc., on a LAN(local area network) or the Internet, then you need to leave it on all the time.
  • If you are running something like SETI@home and you want to produce as many result sets as possible, you need to leave your machine on all the time.

If you do not fall into any of these categories, then you have a choice about whether or not to leave your machine on.

One reason why you might want to turn it off is economic. A typical PC consumes something like 300 watts. Let’s assume that you use your PC for four hours every day, so the other 20 hours it is on would be wasted energy. If electricity costs 10 cents per kilowatt-hour in your area, then that 20 hours represents 60 cents a day. Sixty cents a day adds up to $219 per year.

It’s possible to use the energy-saving features build into modern machines and cut that figure in half. For example, you can have the monitor and hard disk power down automatically when not in use. You’ll still be wasting $100 per year.

 

The argument for leaving your computer on all the time is that turning it on and off somehow stresses the computer’s components. For example, when the CPU chip is running, it can get quite hot, and when you turn the machine off it cools back down. The expansion and contraction from the heat probably has some effect on the solder joints holding the chip in place, and on the micro-fine details on the chip itself. But here are three ways to look at that:

  • If it were a significant problem, then machines would be failing all the time. In fact, hardware is very reliable (software is a whole different story, and there is a lot to be said for rebooting every day).
  • I don’t know a single person who leaves the TV on 24 hours a day. TVs contain many of the same components that computers do. TVs certainly have no problems being cycled on and off.
  • Most vendors will sell you a three-year full-replacement warrantee for about $150. If you are worried about it, spend some of the money you are saving by turning your machine off and buy a service contract. Over three years, you come out way ahead!

How to Speed up your PC by this simple RAM tweak


Well this is a little tut or in other terms a simple hack or a tweak for the techs. SO… Faster PC , first of all why a faster PC ?? Well its not a question of a faster PC but this is more a question of when. If you’ve been running a large application (or several large applications, maybe a game, Photoshop, something like that) the RAM can get taken up quickly. Even when you close down these programs, RAM can still be eaten-up.
You’ll notice this effect at the end of the day. When you first power-up your PC it’s running smoothly, by the end of the day it gets sluggish. Yes, you can get various softwares to solve this. May of which costs but when free things matters, heres how a simple trick can work (in both XP and Vista)
Open up Notepad (I use Notepad++, review coming soon)
Type in MYSTRING=(80000000)
Save the file as MEMORY.VBE (or RAM.VBE if you like…just remember the .VBE)
Make sure you save the file to your DESKTOP.
Just double-click the newly created file on your desktop whenever your PC seems sluggish. It will give your RAM a much needed boost.
Not that if you have less than 128mb of RAM (do you really? If so then Oh! wake up you need an upgrade) change the 80000000 to 160000000 and it should work the same.
RAM Defrag is another nice freeware utility that frees up your RAM however it clears of all the injected DLL’s and the cache so the computer may get more sluggish for a while a Defrag.
You can Download Ram Defrag from this website.
Note that told above is version 2.71 of Ram Defrag which is a freeware, a newer version 2.84 is also available here which is Shareware available here.I am not aware of the working of the version 2.84

How to Speed up your PC by this simple RAM tweak


Well this is a little tut or in other terms a simple hack or a tweak for the techs.
SO… Faster PC , first of all why a faster PC ?? Well it’s not a question of a faster PC but this is more a question of when. If you’ve been running a large application (or several large applications, maybe a game, Photoshop, something like that) the RAM can get taken up quickly. Even when you close down these programs, RAM can still be eaten-up.
You’ll notice this effect at the end of the day. When you first power-up your PC it’s running smoothly, by the end of the day it gets sluggish. Yes, you can get various softwares to solve this. May of which costs but when free things matters, here’s how a simple trick can work (in both XP and Vista)
Open up Notepad (I use Notepad++, review coming soon)
Type in MYSTRING=(80000000)
Save the file as MEMORY.VBE (or RAM.VBE if you like…just remember the .VBE)
Make sure you save the file to your DESKTOP.
Just double-click the newly created file on your desktop when your PC seems sluggish. It will give your RAM a much-needed boost.
Not that if you have less than 128mb of RAM (do you really? If so then Oh! wake up you need an upgrade) change the 80000000 to 160000000 and it should work the same.
RAM Defrag is another nice freeware utility that frees up your RAM however it clears of all the injected DLL’s and the cache so the computer may get more sluggish for a while a Defrag.
You can Download Ram Defrag from this website.
Note that told above is version 2.71 of Ram Defrag which is a freeware, a newer version 2.84 is also available here which is Shareware available here.I am not aware of the working of the version 2.84