Codename: KatanaCodename: KatanaHardwareHardware

Hardware OverviewHardware Overview Processor: 64-bit Hitachi Processor: 64-bit Hitachi SH-4SH-4

Clock Speed: 200 MHzClock Speed: 200 MHz MIPS: 360MIPS: 360 Bus Speed: 800 MB/secondBus Speed: 800 MB/second

Graphics: 128-bit NEC Graphics: 128-bit NEC PowerVR 2DCPowerVR 2DC Resolution: 640x480 or 320x240Resolution: 640x480 or 320x240 Maximum 16,777,216 colorsMaximum 16,777,216 colors Renders 3,000,000 polygons/secondRenders 3,000,000 polygons/second Geometry EngineGeometry Engine

Alpha BlendingAlpha Blending Perspective CorrectionPerspective Correction Gouraud ShadingGouraud Shading Antistropic, bilinear, and trilinear mip Antistropic, bilinear, and trilinear mip

mappingmapping Z-BufferZ-Buffer

8 MB of video RAM8 MB of video RAM

Hardware Overview ContinuedHardware Overview Continued Audio: 45 MHz Yamaha Audio: 45 MHz Yamaha Super IntelligentSuper Intelligent sound processor sound processor

Channels: 64Channels: 64 Sample Rate: 44.1 KHzSample Rate: 44.1 KHz Special Effects: reverb, delay, surround soundSpecial Effects: reverb, delay, surround sound Memory: 2 MBMemory: 2 MB

Memory: 16 MBMemory: 16 MB Operating System: Sega Proprietary OS or Windows CEOperating System: Sega Proprietary OS or Windows CE Game Medium: Proprietary GD-ROM (Gigabyte Disc)Game Medium: Proprietary GD-ROM (Gigabyte Disc)

Transfer Speed: 1800 KB/sTransfer Speed: 1800 KB/s Storage Capacity: 1.2 GigabytesStorage Capacity: 1.2 Gigabytes Memory Buffer: 128KMemory Buffer: 128K

Built in 56 Kbps modemBuilt in 56 Kbps modem

What does all this mean?What does all this mean? Alpha BlendingAlpha Blending

In computer graphics, each pixel has three channels of color information--red, In computer graphics, each pixel has three channels of color information--red, green, and blue--and sometimes a fourth called the alpha channel. This channel green, and blue--and sometimes a fourth called the alpha channel. This channel controls the way in which other graphics information is displayed, such as levels controls the way in which other graphics information is displayed, such as levels of transparency or opacity. Alpha blending is the name for this type of control, of transparency or opacity. Alpha blending is the name for this type of control, and it's used to simulate effects such as placing a piece of glass in front of an and it's used to simulate effects such as placing a piece of glass in front of an object so that the object is completely visible behind the glass, unviewable, or object so that the object is completely visible behind the glass, unviewable, or something in between. something in between.

Perspective CorrectionPerspective Correction The mathematical transformation that is used to produce perspective in 3D The mathematical transformation that is used to produce perspective in 3D

computer graphics is not perfect. Human vision doesn't actually give you a computer graphics is not perfect. Human vision doesn't actually give you a realistic view of the world anyway, but either way the end result is that, without realistic view of the world anyway, but either way the end result is that, without correcting for the mathematical inaccuracy, objects can appear to warp or bend correcting for the mathematical inaccuracy, objects can appear to warp or bend at the side edges, top and bottom of a display, rather like looking through a fish-at the side edges, top and bottom of a display, rather like looking through a fish-eye camera lens. Perspective correction helps to make the displayed image look eye camera lens. Perspective correction helps to make the displayed image look much closer to what you would actually see if you were in the world you're much closer to what you would actually see if you were in the world you're playing in. In short, it makes the 'angle of view' more accurate and prevents playing in. In short, it makes the 'angle of view' more accurate and prevents rendered objects from swimming unrealistically at the periphery of the display.rendered objects from swimming unrealistically at the periphery of the display.

What does all this mean?What does all this mean? Gourard ShadingGourard Shading

Colors are assigned to each Colors are assigned to each vertex, then they are blended vertex, then they are blended across the face of the polygon. across the face of the polygon. Since each vertex is typically Since each vertex is typically associated with at least three associated with at least three distinct polygons, this makes the distinct polygons, this makes the object look natural instead of object look natural instead of faceted. You will notice the image faceted. You will notice the image on the bottom looks smoother on the bottom looks smoother than the image on the top. The than the image on the top. The top image is an example of top image is an example of Flat Flat ShadingShading where-as the image on where-as the image on the bottom is an example of the bottom is an example of Gourard Shading.Gourard Shading.

What does all this mean?What does all this mean? Anistropic, bilinear and trilinear Anistropic, bilinear and trilinear

mip-mappingmip-mapping Mip-mapping is a technique used Mip-mapping is a technique used

where textures are swapped in and out where textures are swapped in and out of a scene, depending on how far you of a scene, depending on how far you are from an object. are from an object.

This reduces blockiness on textures up This reduces blockiness on textures up close and provides more detail from close and provides more detail from afar. For example, if you have a texture afar. For example, if you have a texture that's 256x256 in size but you're so far that's 256x256 in size but you're so far from it that it appears as 24x24, from it that it appears as 24x24, shrinking the original larger texture shrinking the original larger texture down to the smaller size causes it to down to the smaller size causes it to distort and basically look like crap. To distort and basically look like crap. To avoid this, developers will make avoid this, developers will make several versions of the same texture at several versions of the same texture at different sizes, thereby maintaining the different sizes, thereby maintaining the clarity and greatly reducing the blocky clarity and greatly reducing the blocky nature of textures up close.nature of textures up close.

What does all this mean?What does all this mean? Z-BufferZ-Buffer

An area in graphics memory reserved for storing the Z-axis value of each pixel.An area in graphics memory reserved for storing the Z-axis value of each pixel.

Why Sega chose the SH-4Why Sega chose the SH-4 very high performance at a low cost very high performance at a low cost 360 MIPS, 1.4 GigaFLOPS for around 360 MIPS, 1.4 GigaFLOPS for around

$30 in 1998 $30 in 1998 Hitachi has the manufacturing ability to Hitachi has the manufacturing ability to

provide millions of SH-4s provide millions of SH-4s the SH-4 does not need a fan for heat the SH-4 does not need a fan for heat

dissipation (heat sink only) dissipation (heat sink only) simplifying system design simplifying system design smaller, less expensive, lower weight smaller, less expensive, lower weight

power supply needed power supply needed SEGA's software engineers are SEGA's software engineers are

familiar with programming SH series familiar with programming SH series chips chips

SEGA has good relations with Hitachi SEGA has good relations with Hitachi SEGA had some input in the design of SEGA had some input in the design of

the SH-4 the SH-4 floating point unit designed to excel at floating point unit designed to excel at

calculating matrix math arrays  calculating matrix math arrays  able to run Windows CE able to run Windows CE

GD-RomGD-Rom While Dreamcast discs While Dreamcast discs

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

Sega Dreamcast ControllerSega Dreamcast Controller

About the controllerAbout the controllerThe standard Dreamcast controller has 11 buttons plus an analog The standard Dreamcast controller has 11 buttons plus an analog joystick. The buttons include:joystick. The buttons include:

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

Also includes 2 ports for either a memory Also includes 2 ports for either a memory unit, rumble pack, etc.unit, rumble pack, etc.

The controller is a simple device inside. Each button is a simple switch that completes a circuit when the button 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 then compares that data with the instructions in the game software for that button, and triggers the appropriate response.

Inner WorkingsInner Workings

Inner WorkingsInner Workings The joystick also uses a magnet, along The joystick also uses a magnet, along

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

But wait, you forgot something!But wait, you forgot something! The directional pad and triggers work in a completely The directional pad and triggers work in a completely

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

So What Else Can TheSo What Else Can TheDreamcast Do?Dreamcast Do?

Run LinuxRun Linux Setup a router/firewallSetup a router/firewall Run a webserverRun a webserver Run PC GamesRun PC Games Play MP3’sPlay MP3’s Watch DivX moviesWatch DivX movies Build a cluster using Build a cluster using

mosixmosix

LinuxDC Project URL: http://linuxdc.sourceforge.net/

Run NetBSDRun NetBSD

Run a firewall/router/webserverRun a firewall/router/webserver Show that you’re an Show that you’re an ÜbernerdÜbernerd

NetBSD URL: http://www.netbsd.org/Ports/dreamcast/

Develop Your Own SoftwareDevelop Your Own Software

Create your own software using C/C++ in Create your own software using C/C++ in either Linux, or NetBSDeither Linux, or NetBSD

Free Way:Free Way:

Create your own software using the Create your own software using the Windows CE Software Development Kit.Windows CE Software Development Kit.

Expensive Way:Expensive Way:

Emulate Other Game SystemsEmulate Other Game Systems The following systems are currently emulated on the The following systems are currently emulated on the

Dreamcast:Dreamcast: Atari 800, 2600, 5200, 7800, LynxAtari 800, 2600, 5200, 7800, Lynx ColecovisionColecovision Commodore 64Commodore 64 Gameboy/Gameboy AdvanceGameboy/Gameboy Advance Sega Master System, Genesis, Saturn, Game GearSega Master System, Genesis, Saturn, Game Gear Mammotech MSXMammotech MSX MAMEMAME NeoGeo CD, PocketNeoGeo CD, Pocket Super Nintendo, NintendoSuper Nintendo, Nintendo Odyssey 2Odyssey 2 PlaystationPlaystation Sinclair SpectrumSinclair Spectrum

Software Development LinksSoftware Development Links

http://www.atani-software.net/dcprog/http://www.atani-software.net/dcprog/ http://dev.dcemulation.com/http://dev.dcemulation.com/ http://wotsit.thingy.com/haj/dc-index.htmlhttp://wotsit.thingy.com/haj/dc-index.html http://www.ludd.luth.se/~jlo/dc/http://www.ludd.luth.se/~jlo/dc/ http://http://imrtechnology.ngemu.com/dev.htmimrtechnology.ngemu.com/dev.htm