Working of Dreamcast

How Dreamcast Works

Sega Dreamcast hit the market in 1999 and was hailed as an innovative video game system.

With good reason, Popular Science magazine recognized the Sega Dreamcast as one of the most important and innovative products of 1999. Impressive technical specifications, great games and an imaginative advertising campaign heralded the arrival of the latest system from a company known for groundbreaking Video game systems.­

In this edition , you will learn about this phenomenal system, the revolutionary controller that it uses and the proprietary optical storage method chosen by Sega. You will also learn about the VMS, a versatile option that can be used all by itself!

Dreamcast History

An established leader in the arcade, Sega entered the home market right on the heels of Nintendo. Renamed the Sega Master System, the system known as the Mark III in Japan debuted in the United States in 1986. The Sega Master System used an 8-bit CPU, 128K ROM-based operating system and had a 128K of RAM. Games came on two types of cartridges: a large cartridge that could hold a megabit of game code, and a smaller cartridge that held 256 kilobits of game code.

In 1989, Sega introduced the world's first 16-bit home video game system, the Genesis. Based on Motorola's 68000 processor, the system was technically superior to anything else on the market. But the sheer dominance of Nintendo overshadowed the Genesis, when the rival company debuted the Super Nintendo Entertainment System later that same year.

But Sega beat Sony and Nintendo to the punch with a 32-bit system. The Saturn was officially launched on May 11, 1995. Not only was it the first 32-bit system, but it had two 28.8 MHz 32-bit Hitachi SH-2 processors working in parallel! Sega's Saturn was an amazing system with an incredible architecture, but quickly fell behind the other 32-bit system released that year, Sony's Playstation.

Dreamcast was the first video game system to have a built-in modem and 128-bit graphics.

Code-named Katana, the Dreamcast was released in the fall of 1999, the first system to provide a built-in modem and 128-bit graphics.

Dreamcast Console

Lets take a look at the components inside a Dreamcast, and what their capabilities are:

• Processor: 64-bit Hitachi SH-4
  • Processor clock speed: 200 MHz
  • MIPS (Million Instructions Per Second): 360
  • Bus speed: 800 MB per second
  • Cache:
    • Instruction: 8 K
    • Data: 16 K
• Graphics: 128-bit 100 MHz NEC PowerVR 2DC
  • Resolution: 640x480 or 320x240 interlaced
  • Colors: 24-bit (16,777,216) maximum, as well as 16-bit (65,536) mode
  • Polygon rendering: 3,000,000 polygons per second
  • Geometry engine:
    • Alpha blending
    • Perspective correction
    • Gouraud shading
      
      
    • Anistropic, bilinear and trilinear mip mapping
    • Z-buffer
      
      
  • Memory: 8 MB video RAM
• Audio: 45 MHz Yamaha Super Intelligent sound processor
  • Channels: 64
  • Sample rate: 44.1 KHz
  • Special effects: reverb, delay and surround sound
  • Memory: 2 MB RAM
• Memory: 16 MB
• Operating system: Windows CE-based or custom Sega OS
• Game medium: Proprietary GD-ROM (Gigabyte Disc)
  • Transfer speed: 1800 kilobytes per second
  • Storage capacity: 1.2 gigabytes
  • Memory buffer: 128 K
• Modem: 56 kilobits per second (Kbps)

Like the N64 and the PlayStation, the CPU in the Dreamcast is a RISC processor. RISC stands for reduced instruction set computer, and means that the instructions and computations performed by the processor are simpler and fewer. Also, RISC chips are superscalar -- they can perform multiple instructions simultaneously. This combination of capabilities, performing more instructions simultaneously and completing each instruction faster because it is simpler, allows the CPU to perform better than many chips with a much faster clock speed.

Inside a Dreamcast console is the RISC processor, similar to that in other video game systems.

To lower production costs, the graphics processor is combined with circuitry to control the system through a single application specific integrated circuit (ASIC). Simply put, this means that a custom chip is created to manage all of the necessary components that would normally be handled by separate chips. The Dreamcast sound processor is another ASIC; it combines a 45 MHz ARM7 CPU and a Yamaha digital signal processor (DSP). The ARM7 is a 32-bit RISC chip that handles all processing of the compressed adaptive differential pulse code modulation (ADPCM) audio information in real time. ADPCM is used to sample analog information, compress it at a ratio of 4:1 and store it in digital format.

The Dreamcast has several hardware effects that are handled by the PowerVR chip. They include alpha blending, perspective correction and mip mapping.

Alpha blending uses the alpha channel to add transparency effects to an object. This is a special graphics mode used by digital video, animation and video games to achieve certain looks. Essentially, 24 bits are used to define the red, green and blue amounts, 8 bits each, needed to create a specific color. Another 8 bits are used to create a gray-scale mask that acts as a separate layer for representing levels of object transparency. How transparent an object will be is determined by how dark the gray in the alpha channel is. By making an area of the mask dark gray, you can make an object appear to be very transparent; by making it light gray, you can create special fog or water effects.

Mip mapping is a cool process. It is a form of texture mapping in which different sizes of each texture map are made. In essence, the processor replaces the appearance of an object with a more detailed image as you move closer to the object in the game. Let's take a look at how Dreamcast uses these maps in trilinear mip mapping:

1. The system calculates the distance from your viewpoint to an object in the game.
2. The system loads the texture maps for the object. Our three maps will be 64x64 (large), 32x32 (medium), and 8x8 (small).
3. The system determines the exact size that the image map needs to be. Let's say 16x16 for our example here.
4. Based on the size, it decides which two texture maps to use. For our example, it will choose the medium and small texture maps.
5. It will then interpolate (average) between the two texture maps, creating a custom texture map that is 16x16, which it then applies it to the object.

To play a game on Dreamcast, you load a disc.

When a game is put in the console, the following happens:

• You turn the power on.
• The disc spins up to speed.
• While the disc is spinning up, the console loads portions of the operating system from ROM into RAM.
• The game initialization sequence is loaded into RAM.
• You interact with the game via the controller.
• As each specific part of the game is requested, the application code and hardware-render geometry are loaded into RAM, while the video and audio portions are usually streamed directly from the CD.
• The PowerVR chip coordinates everything. In addition to processing graphics, it receives the input from the controller, pulls the data from RAM, sends it to the CPU and directs the use of the audio processor.
• You are finally beaten by the game and turn it off.

The Dreamcast is the first console that has a built-in 56 Kbps modem. It was added to enable online play over a phone line, allowing users to play games against each other across long distances. In addition to the built-in modem, Sega is working on a cable or DSL external modem. Broadband networks are being developed that will take advantage of such a modem and enable fast online games for the Dreamcast.

Dreamcast Controller

As it is with other systems, the controller is the primary user interface for the Dreamcast. The standard Dreamcast controller has 11 buttons plus an analog joystick. The buttons include:

• four buttons arranged as a directional pad on the top left
• Start button in the top middle
• four action buttons on the top right
• one analog trigger on the front left
• one analog trigger on the front right
• analog joystick on the top left

Inside a Dreamcast controller

Although each button can be configured to perform a specific and distinctive action, all of the buttons, except for the two analog triggers and joystick, work on the same principle. In essence, each button is a switch that completes a circuit whenever it is pressed. A small metal disk beneath the button is pushed into contact with two strips of conductive material on the circuit board inside the controller. While the metal disk is in contact, it conducts electricity between the two strips. The controller senses that the circuit is closed and sends that data to the Dreamcast. The CPU compares that data with the instructions in the game software for that button, and triggers the appropriate response. There is also a metal disk under each arm of the directional pad. If you're playing a game in which pushing down on the directional pad causes the character to crouch, a similar string of connections is made from the time you push down on the pad to when the character crouches.

The analog joystick and triggers work in a completely different way from the buttons described above. The triggers each have a tiny magnet attached to the end of the trigger arm. When the trigger is depressed, the magnet is pushed toward a sensor mounted on the controller's circuit board. Through the process of induction, the magnet creates resistance to the current passing through the sensor. On the bottom of the magnet is a layer of foam padding. Pushing harder on the trigger compresses the padding, which brings the magnet closer to the sensor. The closer the magnet is to the sensor, the more resistance is induced. This variable resistance makes the triggers pressure-sensitive!

The joystick also uses a magnet, along with four small sensors. The sensors are arranged like a compass, with one at each of the cardinal points (north, south, east, west). The base of the joystick is shaped like a ball, with tiny spokes radiating out. The ball sits in a socket above the sensors. Spikes on the socket fit between the spokes on the ball. This allows for an extraordinary amount of movement without letting the joystick twist out of alignment with the sensors. As the joystick is moved, the magnet in the base moves closer to one or two of the sensors, and farther from the others. The system monitors the changes in induction caused by the magnet's movement to calculate the position of the joystick.

The controller has two expansion ports where memory cards, tremor packs, Visual Memory System (VMS) devices and other system additions can be inserted.

A popular option is the tremor pack, which provides force feedback. This feature provides a tactile stimulation to certain actions in a game. For example, in a racing game, you might feel a jarring vibration as your car slams into the wall. Force feedback is actually accomplished through the use of a very common device, a simple electric motor. The shaft of the motor holds an unbalanced weight. When power is supplied to the motor, it spins the weight. Because the weight is unbalanced, the motor tries to wobble. But since the motor is securely mounted inside the tremor pack, the wobble translates into a shuddering vibration of the controller itself.

While standard memory cards can be used with the Dreamcast, the VMS units are unique to this console. The VMS is actually a tiny Personal Digital Assistant (PDA) that fits into the upper expansion port of the controller.

About the size of a business card, each VMS unit contains:

• 8-bit Hitachi CPU
• 128 K memory (Flash RAM)
• Monochrome LCD panel, 48 pixels wide by 32 pixels high
• Two button (watch) batteries, with auto-off function, to provide power
• One-channel sound

When the VMS is inserted into a Dreamcast controller, its LCD can be used to perform some unique functions. For example, in a football game, you can select plays without your opponent seeing what they are. In addition to serving as a memory card for the Dreamcast, the VMS can be used as a stand alone device. Small games, as well as traditional PDA functions like a calendar and phone directory, can be downloaded to the VMS and taken with you.

Dreamcast Games

While Dreamcast games are similar to CD-ROM, the actual optical disc used is proprietary, and can hold up to 1.2 gigabytes of information. This is a lot of space -- most games use only a fraction of it for the actual game. What can eat up the space are the incredible full motion video intros and intermissions included in most Dreamcast games.

The Dreamcast has a drive similar to other CD-ROM drives, but the optical disc is proprietary.

There is a noticeable delay while the game is loaded from the CD, which you do not get with cartridge-based games. Of course, the trade-off for faster loading is a significantly smaller amount of storage on a cartridge. Most Dreamcast games use a customized version of Microsoft Windows CE as their operating system; but some use Sega's proprietary Dreamcast operating system.

Dreamcast CDs are just as susceptible to scratches and intense heat as normal CDs. Even more so in fact, since a scratch on a game CD can make it totally unusable.

The games available for the Dreamcast cover all the categories, and its library of games is increasing rapidly. Game prices range from under $20 for certain preplayed titles to over $75 for some of the hottest new games.

Working of GameCube

How GameCube Works

In the United States, the Nintendo GameCube is the undeniable underdog of the "console wars." Sony's PlayStation 2 and Microsoft's Xbox certainly sell better, and they tend to get more media attention. Toward the end of 2002, for example, the PlayStation 2 stirred up a lot of controversy with its new game Grand Theft Auto : Vice City, and Microsoft had a hit with Xbox Live, its online gaming program. Once the undisputed king of home video games, Nintendo seems to be struggling just to hold its own.

The GameCube comes in a variety of colors like its predecessor Nintendo 64.

But if you've actually spent any time with a GameCube, you may be confused by its reputation as a third-rate system. It's hard to see ground-breaking GameCube games like Metroid Prime and Super Mario Sunshine as anything less than state of the art. No matter how it fares in sales, this console is definitely a remarkable technological achievement.

we'll find out what the GameCube has under the hood, and we'll see how it stacks up to the competition.

Inside the Cube

The GameCube is not actually a cube; at 6 inches long, 6 inches wide and 4.3 inches tall (15 x 15 x 11 cm), it is a very compact rectangular block. Like its predecessor, the Nintendo 64, the GameCube comes in a variety of colors. A handle on the back of the machine makes it easy to transport.

The limited edition platinum GameCube

While Nintendo didn't spend a lot of time on the aesthetics of the console, the insides are pretty impressive. Let's take a look at the components inside the GameCube and see what they can do. (

• The GameCube is powered by a 485-megahertz (MHz) IBM microprocessor, an extension of the IBM PowerPC architecture. It has a maximum bus transfer rate of 2.6 GB per second. The Gekko also features a whopping 256 kilobytes (KB) of level 2 (L2) cache memory.

• An ATI 162-MHz graphics chip, called "Flipper," allows the GameCube to produce about 12 million polygons per second. Polygons are the building blocks of 3-D graphics. Increasing the number of polygons results in sharper, more detailed images. In comparison, the Nintendo 64 produces 150,000 polygons per second.

• A special 16-bit digital signal processor supports 64 audio channels.

• The GameCube has 40 MB of RAM (24 MB 1T-SRAM, 16 MB of 100-MHz DRAM).

• Gamers can now attach a modem to the GameCube. The modem fits into a serial port on the underside of the console. It allow users to connect to an online network, where they can trade data and play games over the Internet. For more information, check out Befor you buy a Modem Adapter and Before you buy a Broadband Adapter on Nintendo's official site.

56K modem

Broadband modem

• Other GameCube features include:
  • Four game controller ports

  • The GameCube's wireless controller

    Wavebird wireless RF game controller (sold separately)
  • Two slots for Memory Cards
  • High speed parallel port
  • Two high-speed serial ports
  • Analog and digital audio/video outputs

One thing that you won't find in Nintendo's GameCube is a DVD player, which the PS2 and Xbox both have. Nintendo says it's sticking to the basics and what it knows best -- video games.

The Games

The GameCube is the first Nintendo console not to use game cartridges. Instead, the GameCube uses 1.5-GB proprietary optical discs with a diameter of 8 cm (3.14 inches). A compact disc has a diameter of 12 cm (4.72 inches), which is the size of the Sony game discs. Since the GameCube operates with discs, the Nintendo 64 games are not compatible with it.

The GameCube uses small proprietary discs instead of cartridges.

When you get down to it, the biggest difference between the different consoles is their respective game catalogs. Gamers typically pick the console that supports the titles they're most interested in. The PlayStation 2 has a huge lead in sheer number of games because it plays original PlayStation games and it hit store shelves well before the other consoles. The X-box has fared well largely because of high profile games aimed at teenage and adult players (such as Halo and Splinter Cell).

Nintendo's main strategy has been to launch exclusive games based on well-known established characters. For example, Mario, Star Fox and Metroid's Samus, who were all featured in hit games on earlier Nintendo consoles, will appear only in GameCube titles. Nintendo has also worked out a deal with Capcom for exclusive rights to new Resident Evil games.

A screen shot from Metroid Prime

A screen shot from Super Mario Sunshine

As it turned out, using established characters in the console's biggest games had a significant downside. With the cartoon Mario characters front and center, the GameCube was immediately branded as a "kid's console." While it does have many games aimed at older players, it hasn't hit on anything as controversial as the PlayStation 2's Grand Theft Auto series or as lauded as X-Box's shooter Halo.

Resident Evil Zero	Spider-man: The Movie
Super Smash Bros. Melee	Madden NFL 2003

One thing the GameCube does have over the competition is its ability to interact with the Game Boy Advance (GBA), Nintendo's handheld system. The GBA plugs directly into the GameCube's controller port to allow the two systems to communicate with select games. In May of 2003, Nintendo will release an accessory that will let you play Game Boy games on a TV, through the GameCube.

The Game Boy Player, due out in May of 2003

Ultimately, the winner in the game console wars will be the gamers themselves. As the console manufacturers continue to try to top one another to attract increasingly discriminating buyers, the great titles keep on coming.

Working of Cable Modems

How Cable Modems Work

Motorola SURFboard modem

For millions of people, television brings news, entertainment and educational programs into their homes. Many people get their TV signal from cable television (CATV) because cable TV provides a clearer picture and more channels. (See How Cable TV Works for details.)

Many people who have cable TV can now get a high-speed connection to the Internet from their cable provider. Cable modems compete with technologies like asymmetrical subscriber lines (ADSL). If you have ever wondered what the differences between DSL and cable modems are, or if you have ever wondered how a computer network can share a cable with dozens of television channels, then read on. In this article, we'll look at how a cable modem works and see how 100 cable television channels and any Web site out there can flow over a single coaxial cable into your home.

Extra Space

You might think that a television channel would take up quite a bit of electrical "space," or bandwidth, on a cable. In reality, each television signal is given a 6-megahertz (MHz, millions of cycles per second) channel on the cable. The coaxial cable used to carry cable television can carry hundreds of megahertz of signals -- all the channels you could want to watch and more. (For more information, see How Television Works.)

In a cable TV system, signals from the various channels are each given a 6-MHz slice of the cable's available bandwidth and then sent down the cable to your house. In some systems, coaxial cable is the only medium used for distributing signals. In other systems, fiber-optic cable goes from the cable company to different neighborhoods or areas. Then the fiber is terminated and the signals move onto coaxial cable for distribution to individual houses.

Streams

When a cable company offers Internet access over the cable, Internet information can use the same cables because the cable modem system puts downstream data -- data sent from the Internet to an individual computer -- into a 6-MHz channel. On the cable, the data looks just like a TV channel. So Internet downstream data takes up the same amount of cable space as any single channel of programming. Upstream data -- information sent from an individual back to the Internet -- requires even less of the cable's bandwidth, just 2 MHz, since the assumption is that most people download far more information than they upload.

Putting both upstream and downstream data on the cable television system requires two types of equipment: a cable modem on the customer end and a cable modem termination system (CMTS) at the cable provider's end. Between these two types of equipment, all the computer networking, security and management of Internet access over cable television is put into place.

Inside the Cable Modem

Cable modems can be either internal or external to the computer. In some cases, the cable modem can be part of a set-top cable box, requiring that only a keyboard and mouse be added for Internet access. In fact, if your cable system has upgraded to digital cable, the new set-top box the cable company provides will be capable of connecting to the Internet, whether or not you receive Internet access through your CATV connection. Regardless of their outward appearance, all cable modems contain certain key components:

• A tuner
• A demodulator
• A modulator
• A media access control (MAC) device
• A microprocessor

Inside the Cable Modem: Tuner

The tuner connects to the cable outlet, sometimes with the addition of a splitter that separates the Internet data channel from normal CATV programming. Since the Internet data comes through an otherwise unused cable channel, the tuner simply receives the modulated digital signal and passes it to the demodulator.

In some cases, the tuner will contain a diplexer, which allows the tuner to make use of one set of frequencies (generally between 42 and 850 MHz) for downstream traffic, and another set of frequencies (between 5 and 42 MHz) for the upstream data. Other systems, most often those with more limited capacity for channels, will use the cable modem tuner for downstream data and a dial-up telephone modem for upstream traffic. In either case, after the tuner receives a signal, it is passed to the demodulator.

Inside the Cable Modem: Demodulator

The most common demodulators have four functions. A quadrature amplitude modulation (QAM) demodulator takes a radio-frequency signal that has had information encoded in it by varying both the amplitude and phase of the wave, and turns it into a simple signal that can be processed by the analog-to-digital (A/D) converter. The A/D converter takes the signal, which varies in voltage, and turns it into a series of digital 1s and 0s. An error correction module then checks the received information against a known standard, so that problems in transmission can be found and fixed. In most cases, the network frames, or groups of data, are in MPEG format, so an MPEG synchronizer is used to make sure the data groups stay in line and in order.

Inside the Cable Modem: Modulator

In cable modems that use the cable system for upstream traffic, a modulator is used to convert the digital computer network data into radio-frequency signals for transmission. This component is sometimes called a burst modulator, because of the irregular nature of most traffic between a user and the Internet, and consists of three parts:

• A section to insert information used for error correction on the receiving end
• A QAM modulator
• A digital-to-analog (D/A) converter

Inside the Cable Modem: MAC

The MAC sits between the upstream and downstream portions of the cable modem, and acts as the interface between the hardware and software portions of the various network protocols. All computer network devices have MACs, but in the case of a cable modem the tasks are more complex than those of a normal network interface card. For this reason, in most cases, some of the MAC functions will be assigned to a central processing unit (CPU) -- either the CPU in the cable modem or the CPU of the user's system.

Microprocessor

The microprocessor's job depends somewhat on whether the cable modem is designed to be part of a larger computer system or to provide Internet access with no additional computer support. In situations calling for an attached computer, the internal microprocessor still picks up much of the MAC function from the dedicated MAC module. In systems where the cable modem is the sole unit required for Internet access, the microprocessor picks up MAC slack and much more. In either case, Motorola's PowerPC processor is one of the common choices for system designers.

Cable Modem Termination System

At the cable provider's head-end, the CMTS provides many of the same functions provided by the DSLAM in a DSL system. The CMTS takes the traffic coming in from a group of customers on a single channel and routes it to an Internet service provider (ISP) for connection to the Internet. At the head-end, the cable providers will have, or lease space for a third-party ISP to have, servers for accounting and logging, Dynamic Host Configuration Protocol (DHCP) for assigning and administering the IP addresses of all the cable system's users, and control servers for a protocol called CableLabs Certified Cable Modems -- formerly Data Over Cable Service Interface Specifications (DOCSIS), the major standard used by U.S. cable systems in providing Internet access to users.

The downstream information flows to all connected users, just like in an Ethernet network -- it's up to the individual network connection to decide whether a particular block of data is intended for it or not. On the upstream side, information is sent from the user to the CMTS -- other users don't see that data at all. The narrower upstream bandwidth is divided into slices of time, measured in milliseconds, in which users can transmit one "burst" at a time to the Internet. The division by time works well for the very short commands, queries and addresses that form the bulk of most users' traffic back to the Internet.

A CMTS will enable as many as 1,000 users to connect to the Internet through a single 6-MHz channel. Since a single channel is capable of 30 to 40 megabits per second (Mbps) of total throughput, this means that users may see far better performance than is available with standard dial-up modems. The single channel aspect, though, can also lead to one of the issues some users experience with cable modems.

Pros and Cons to Cable Modems

If you are one of the first users to connect to the Internet through a particular cable channel, then you may have nearly the entire bandwidth of the channel available for your use. As new users, especially heavy-access users, are connected to the channel, you will have to share that bandwidth, and may see your performance degrade as a result. It is possible that, in times of heavy usage with many connected users, performance will be far below the theoretical maximums. The good news is that this particular performance issue can be resolved by the cable company adding a new channel and splitting the base of users.

Another benefit of the cable modem for Internet access is that, unlike ADSL, its performance doesn't depend on distance from the central cable office. A digital CATV system is designed to provide digital signals at a particular quality to customer households. On the upstream side, the burst modulator in cable modems is programmed with the distance from the head-end, and provides the proper signal strength for accurate transmission.

Working of Xbox 360

How Xbox 360 Works

Microsoft's first video game console, the Xbox, has sold more than 20 million units worldwide since its introduction in 2001. Despite the Xbox's impressive power, the list of big-name video game titles to support it and the success of the Xbox's online component, Xbox LIVE, Sony's PlayStation 2 still outsold it.

As the game industry moved into the next generation of video game technology, Microsoft was determined to dethrone Sony's PlayStation. Enter the Xbox 360.

Xbox 360.

Microsoft rebuilt the Xbox from the ground up. From the name to the look to hardware and features, the Xbox 360 is a radically different and more powerful machine than its predecessor. Far more than a video game console, the Xbox 360 is a total media center that allows users to play, network, rip, stream and download all types of media, including high-definition movies, music, digital pictures and game content.

In this article, we will learn about the hardware and features that make the Xbox 360 a leap forward into the next generation of gaming consoles.

The Xbox 360, like all video game consoles, is just a computer with hardware and software dedicated to the function of running video game software. The original Xbox was essentially a Windows PC with a modified Pentium III processor, some relatively powerful graphics and audio hardware and a modified version of the Microsoft operating system Windows 2000, all packaged in that distinctive black box. The Xbox 360 is also a specially packaged computer, but once you look inside, you realize that this console has quite a bit under the hood:

• Custom IBM Power PC-based CPU with three 3.2 GHz cores
• Custom ATI graphics processor with 10 MB embedded DRAM
• 512 MB 700 MHz GDDR3 RAM
• Detachable and upgradeable hard drive -- all models except the Core system
• 12x dual-layer DVD-ROM
• Support for up to four wireless game controllers
• Three USB 2.0 ports
• Two memory unit slots

As you can see, Microsoft intends the Xbox 360 to be a serious game machine. The company is also serious about reaching more audiences with the Xbox 360. On the next page, we'll look at variations of the Xbox 360 that are marketed to different kinds of gamers.

Xbox 360 Consoles

Microsoft released two versions of the Xbox 360 in November 2005: the Xbox 360 Premium Package and Xbox 360 Core System. Since then, the lineup has undergone some changes. The Premium Package is now known simply as the Xbox 360 console. A new Elite system hit store shelves in April 2007. Microsoft announced another new system, the Xbox 360 Arcade, in October 2007.

The Xbox 360 debuted at the 2005 E3 Expo Microsoft booth.

The Core System is "plug and play" -- in addition to the console, it includes a wired controller and an AV cable. The Xbox 360 comes with a wireless controller, an HD AV cable, an Ethernet connectivity cable, a headset and a removable 20-GB hard drive. Initially, it also included a DVD remote, but this is no longer available as part of the package.

The Xbox 360 Elite is similar to the main Xbox 360, with a black case, matching wireless controller and headset. It also includes a larger 120-GB hard drive and an HDMI cable.

To combat Nintendo's surprise powerhouse, the Wii, Microsoft announced the Xbox 360 Arcade in October 2007. Aimed at casual gamers, the console will come with between three and five Xbox LIVE Arcade games and will probably include "Pac-Man," "Uno" and "Luxor 2."

Microsoft has also prepared subtle variations of the console for marketing tie-ins. To commemorate the release of "The Simpsons Movie," Microsoft created a run of 100 limited-edition Simpsons Xbox 360s, which were given away in promotions. Fans of Bungie's "Halo" game series can purchase the "Halo 3" limited edition Xbox 360, which comes in "Spartan green and gold" and features a matching controller.

On the next page we will see what makes the Xbox 360 tick -- the central processing unit, or CPU.

Xbox SalesBecause of delays in manufacturing, there were not enough Xbox 360s to meet the demand of the 2005 holiday season. As a result, Xbox 360s were selling for as much as $2,000 on Web sites like eBay, and initial sales figures were poor. However, Microsoft still got a jump on its competitors, as the PlayStation 3 and the Nintendo Wii did not release until 2006. According to industry analyst the NPD Group, as of August 2007, the Xbox 360 sold 6.3 million Xbox 360s in the United States, to 4 million of Nintendo's Wii and 1.75 million Sony Playstation 3s.

CPU: The Heart of the 360

As with any computer, the CPU is the heart of the Xbox 360. Microsoft has outfitted the 360 with a 165-million transistor, multi-core processor running three 3.2-GHz PowerPC cores.

Each core on the chip functions as a separate processor. Recently, hardware manufacturers have started combining several cores, or processors, onto one chip. This is a multi-core processor. Multi-core processors offer a combination of tremendous computing capabilities and efficient power consumption. They split
heavy work loads over multiple powerful processors rather than giving all the work to one super-powerful processor.

The Xbox 360 on display at the 2005 E3 Expo.

The other interesting thing to note about the Xbox 360 CPU is that each core is capable of processing two threads simultaneously. Think of a thread as a set of instructions for a program's job. The core processes these instructions and does the heavy lifting to get the job done. A conventional processor can run a single execution thread. Because the Xbox 360 cores can each handle two threads at a time, the 360 CPU is the equivalent of having six conventional processors in one machine.

What this means when you are playing video games is that the Xbox 360 can dedicate one core entirely to producing sound, while another may run the game's collision and physics engine. The system may allocate an entire processor just to rendering hi-def graphics. It's really up to the game developers how the system's considerable resources are used. With a multi-core processor, the system is powerful enough to pull off the computational demands needed for an amazing gaming experience without even breaking a sweat.

360 DegreesAccording to J. Allard, Microsoft Corporate Vice President and chief XNA architect, in an interview with Gamespot, "If we were building another console in the 3D era, we'd just call it Xbox 2 ... So, we eliminated Xbox 2 from the list. So, the name that we came up with was Xbox 360, because we are putting the gamer at the center of the experience."

The graphics processor unit, or GPU, is responsible for the heavy-lifting for the console's beautiful, high-resolution images.

The GPU

Another powerful asset in the Xbox 360 is the Graphics Processor Unit (GPU). The Xbox 360 boasts the new, custom-built 500-MHz ATI Graphics Processor card with 10 MB of embedded DRAM. While the 500-MHZ graphics processor is powerful, and 10 MB of DRAM provides ample memory for the GPU to do its job, the most innovative thing about this card is that it is built on unified shader architecture.

Shaders are computer programs that determine the final look of what you see on the screen when you're looking at computer animation. Shaders take rendered 3-D objects built on polygons (the building blocks of 3-D animation) and make them look more realistic. There are two types of shaders: pixel shaders and vertex shaders.

Pixel shaders alter the lighting, color and surface of each pixel. This in turn affects the overall color, texture and shape of 3-D objects built from these pixels. Pixel shaders help "smooth out" 3-D objects, giving them a more organic texture. To learn more about pixel shaders, see nVidia: Pixel Shaders.

The Xbox 360 with a custom, wood-grain faceplate.

Vertex shaders work by manipulating an object's position in 3-D space. "Vertex" refers to the intersection of two coordinates in space. The machine maps the position of an animated object in 3-D space by giving it a value. These values are the x, y and z coordinates. By manipulating these variables, a vertex shader creates realistic animation and special effects such as "morphing."

In real-time graphics, like the kind you see in video games, shaders work with the graphics processor. The shaders make billions of computations every second to perform their specific tasks. These computations are performed in steps through a series of computational components. Think of an assembly line. In the world of hardware, these assembly lines are called pipelines.

Traditionally, pixel shaders and vertex shaders have dedicated pipelines because each one has very specific and differing needs. As we learned before, the new ATI graphics card in the Xbox 360 has unified shader architecture. What that means is that now, both shader types share the same pipelines. ATI figured out a way at the hardware level to address the needs of both types of shaders using the same pipeline.

The apparent advantage of sharing pipelines is to add more assembly lines, making computation that much faster. ATI claims that this unified shader architecture allows for 48 billion shader operations per second. The Xbox 360 is the first device to use this type of architecture.

On the next , we'll learn about how the Xbox 360 fits in with your home entertainment system.

Jacks, Tracks and Other 360 Features

Input/Output
The Xbox 360 supports up to four wireless controllers at once. It also has three USB 2.0 jacks, two in the front and one in the back that can be used to plug in wired controllers for play or wireless controllers when they need to be charged. The USB jacks can also be used to connect devices like digital cameras, MP3 players and computer keyboards to the 360 (but the keyboard can only be used for text entry, not game play).

Online
The Xbox 360 has an Ethernet port to hook up to a broadband connection, as well as a slot for a WiFi card. The 360 is WiFi-ready "out of the box" and the bundle includes a connectivity Ethernet cable.

TV Connections
The Xbox 360 comes standard with both composite and component video connections to hook up to a TV. There are also optional connections for S-Video and VGA, and the console supports some SCART-type adapters used in Europe. The Xbox 360 Core System includes a standard-definition AV cable, while the other Xbox 360 bundles come with an AV HD cable and a media remote.

Audio
The Xbox 360 has multi-channel surrounding sound that supports 256 channels of 48 KHz, 16-bit digital audio. The 32-bit audio processing is handled by the CPU. One of the most talked about new audio features of the Xbox 360 is customizable soundtracks. No matter what video game you are playing, you can play or stream your music during game play.

Removable Hard Drive and Storage
The original Xbox was quite innovative in that it had an 8-GB hard drive built into the console. The 360 takes the hard-drive concept one step further: The Xbox 360 includes a removable 20-GB hard drive, and the Xbox 360 Elite has a removable 120-GB hard drive. The Xbox 360 also supports up to two 64-MB memory cards at one time.

An Xbox 360's external hard drive

The Disc Drive
In keeping with the idea that the Xbox 360 is a full media center, it sports a 12x dual-layer DVD-ROM that can read DVD-Video, DVD-ROM, DVD-R/RW, DVD+R/RW, CD-DA, CD-ROM, CD-R, CD-RW, WMA CD, MP3 CD and JPEG Photo CD. You can buy an external HD-DVD player for the Xbox 360. The 360 does not, however, support Blu-ray.

Cooling
The original Xbox took a lot of criticism for how large it was. The cooling system that kept the Xbox's rather hefty processor cool was the single greatest factor that contributed to the console's robust size. Microsoft changed all this for the Xbox 360.

In order to fit all that hardware into the stylish and slim form factor of the Xbox 360, Microsoft devised a cooling system that combines a small, vacuum-sealed, liquid-cooled system with fans to maintain a comfortable temperature inside the 360. The system regulates the temperature of the cores and adjusts the flow of liquid and fan speed accordingly. Additionally, the cooling system monitors the core's workload: If one or more cores are not needed for the job at hand (for instance, if you are using the Xbox 360 to watch a DVD), then the unused cores are automatically turned off.

Other Accessories
There are dozens of accessories on the market for the Xbox 360, including headsets, wireless controllers, cooling systems, rechargeable batteries and more. You can play compatible Xbox 360 games on your Windows computer with the Wireless Gaming Receiver for Windows. The Live Vision Camera allows players to create an in-game version of themselves in select games. The Xbox 360 Wireless Racing Wheel is a force-feedback steering wheel controller with standard gamepad buttons and floor-mounted accelerator and brake pedals. The Messenger Kit attaches to Xbox 360 controllers and features a keyboard to message other players.

Next we'll take a look at the Xbox 360 controller and how it has evolved from the original Xbox controller.

Xbox Controller

The design for the Xbox 360 controller is based largely on the one used for the original Xbox -- the Controller S.

The new Xbox 360 controller is a familiardesign with several new features.

The most noticeable difference in the Xbox 360 controllers from those for the original Xbox is that most of them are wireless. Microsoft created a proprietary technology to deal with some of the latency and bandwidth issues that can be a problem for some wireless controllers. The Xbox 360 can support up to four wireless controllers at one time.

The wireless controller comes with all Xbox 360 bundles except for the Core system, which includes a wired controller with a nine-foot cable. Everything else about the design is the same. Of course, wireless controllers are available separately if you choose to upgrade.

Control Issues When the original Xbox was released in 2001, one of the most common complaints about the new console was the controller. Gamers worldwide criticized it for being too large and having poor button spacing. In Japan, where the Xbox sales were already suffering, Japanese gamers all but refused to use the large Xbox controllers, opting instead for smaller, third-party ones. This compelled Microsoft to create a smaller, redesigned controller for Asian markets that was released in winter 2002. Shortly after that, Microsoft released a slightly improved version of the Japanese controller in the west called the Controller S. The Controller S is now the standard Xbox controller that is shipped with all Xbox consoles.

The new Xbox 360 wireless controllers can be powered by either a pair of traditional AA batteries or a rechargeable battery pack. The battery pack can be "flash charged" in a charger or "trickle charged" via a USB connection to the console, and it alerts the user when its charge is running low.

The Xbox 360 controller has a Guide button in the center of its face that provides a new functionality. This button is divided into four quadrants that light up to provide gamers with different types of information during game play. (Incidentally, the "ring of light" power button on the console also provides this function.) For instance, during a split screen multiplayer match, a particular quadrant will light up to indicate to a player which part of the screen he or she is playing on at that time. The Guide button can also light up to let a player know he has received a message from another gamer. In this case, when the user pushes the button, he or she visits the Xbox dashboard (the equivalent of a PC's desktop). The dashboard provides access to features like messaging friends, downloading content, voice chat and customizing soundtracks, all while staying in the game. The controller has a standard headphone jack on the back so that the user can plug in a headset for voice communication during game play. Some wireless headsets will also work with the Xbox 360.

The new Xbox 360 controller has the same basic familiar button layout as the Controller S except that a few of the auxiliary buttons have been moved. The "back" and "start" buttons have been moved to a more central position on the face of the controller, and the "white" and "black" buttons have been removed and replaced with two new shoulder buttons that are positioned over the analog triggers on the back of the controller.

One of the great features of Xbox 360 is its ability to let players compete against one another online. Learn about Xbox LIVE next .

Xbox LIVE

Xbox LIVE is an online subscription service that allows Xbox gamers to play video games together and download additional game content using the Internet. Once online, gamers can play one another over the Internet and talk to each other in real-time using the headset (included in the bundle). Xbox LIVE has created a huge online community of gamers challenging one another worldwide. The Xbox 360 will also usher in the next generation of online game play and online community with the new, revamped Xbox LIVE.

The Xbox 360 is WiFi-ready so that gamers can jump on Xbox LIVE wirelessly.

The new Xbox LIVE has enhanced matchmaking and feedback systems as well as voice chat and video conferencing. It has a new, more seamless interface and is a generally more robust system for communicating during online gaming. Xbox LIVE on the 360 is divided into two services: Xbox LIVE Silver and Xbox LIVE Gold.

Xbox LIVE Silver is a free service that ships with all Xbox 360s and allows any Xbox 360 user with a broadband connection to get online and create a gamer tag as well as a new ID type called a gamer card. The gamer card is a profile that displays a gamer's interests, skill level, competitiveness and gaming accomplishments. In addition, gamers can use Xbox LIVE Silver to chat, download content and play certain games. Xbox LIVE Silver allows gamers to access most of the features of Xbox LIVE. The one key feature missing from the free service is the ability to play multiplayer games online.

In order to play in multiplayer matches online, you must upgrade to the subscription service known as Xbox LIVE Gold. The Gold service has all the functionality of Silver plus the ability to play multiplayer games. Additionally, Xbox LIVE Gold has exclusive content, tournaments and events.

Serious gamers know the Xbox 360 has a great slate of games available for it.

Xbox Games

As history has shown time and again, the latest and greatest console is nothing without great games. Microsoft has set out to create a series of blockbuster titles in-house for the Xbox 360 as well as make deals with as many third-party developers as possible. Game developers are attracted to the prospect of creating games on such a powerful canvas, and in the years to come they will find new ways to build games that push the potential of the Xbox 360.

One game franchise more than any other has defined the success of the Xbox and Xbox 360: "Halo." Microsoft acquired game developer Bungie Studios in 2000 to bring the game to the original Xbox. The game took off and spawned a sequel. Then, on September 25, 2007, came "Halo 3." In 12 days, it had already surpassed the biggest-selling game in 2007, "Wii Play," selling 3.3 million copies and pushing the Xbox 360 ahead of the Wii in numbers of consoles sold for the month [source: Casamassina]. Microsoft even released a special "Halo"-themed Xbox 360 console for hard-core fans.

Halo 3 is one of the most successful video games in history by earning over 300 million dollars in first week sales. Read about some of the Halo 3 features.

The game even seems to have affected the motion picture industry. Ticket sales for the October 5, 2007, weekend only totaled $80 million, a 27 percent decrease from the same weekend the year before [source: Brodesser-Akner, Claude]. Some movie executives blame Bungie and Microsoft for stealing their sales.

Below is a list of games that released with the Xbox 360. For a complete list of current and upcoming games, check out Xbox.com games.

• "Kameo: Elements of Power"
• "Perfect Dark Zero"
• "Project Gotham Racing 3"
• "Call of Duty 2"
• "Need for Speed Most Wanted"
• "Peter Jackson's King Kong"
• "Madden NFL 06"
• "GUN"
• "Condemned: Criminal Origins"
• "NBA 2K6"
• "Ridge Racer 6"
• "Tony Hawk's American Wasteland"
• "QUAKE 4"
• "Tiger Woods PGA TOUR 06"
• "Amped 3"
• "FIFA 06: Road to FIFA World Cup"
• "NHL 2K6"
• "NBA Live 06"