Sega Dreamcast

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Dreamcast.jpg
Sega Dreamcast
Manufacturer: Sega
Variants: Sega NAOMI, Atomiswave, Sega Aurora
Release Date RRP Code

The Sega Dreamcast (ドリームキャスト), code-named "Katana" and "Dural" during development, is a video game console manufactured by Sega as a successor to the Sega Saturn. It was the first machine released in what is now known as the sixth generation of video game consoles, with its sixth-generation peers being the PlayStation 2, the Nintendo GameCube and the Xbox. The Dreamcast had an arcade counterpart, the Sega NAOMI (which, in turn, was succeeded by the Sega Hikaru and NAOMI 2).

The Dreamcast was Sega's last home console, and developed primarily to detoxify the Sega brand. Western trust in Sega had been reduced following the dismal performance of the Sega Mega-CD, Sega 32X and Sega Saturn, and Sega were keen to regain the trust seen in the days of the Sega Mega Drive. Faced with increased competition from Sony, Nintendo and Microsoft, the Dreamcast landed in a distant fourth place, and Sega largely pulled out of the console business as a result. By the end of its lifespan, it sold 10,6 million consoles worldwide.

Many of Sega's games still in development for the Dreamcast at the time of its discontinuation were eventually released for other platforms, leading to the Dreamcast Diaspora. However, the innovative features of the Dreamcast along with a strong library of games means the console still has a large, dedicated fanbase, to the extent that Dreamcast games are still being released commercially today.

Hardware

The Sega Dreamcast lays claim to being a "128-bit" video game console, although like many consoles of the era, this concept was mainly used as marketing jargon to assert a position above systems like the 32-bit PlayStation and "64-bit" Nintendo 64 (and save for a few handhelds and the PlayStation 2, it was the last mainstream console to make these sorts of claims). It is widely considered to be the console which ushered in what is now known as the "sixth generation" of video game consoles, beginning in 1998 and ending around 2007 when the major industry players began to focus their attention on seventh generation systems.

The Dreamcast is a small, white box with four control ports (taking design cues from the Nintendo 64), a removable modem, disc drive and an extension port (as well as the expected AV and power inputs). It is not backwards compatible with any prior Sega hardware or software (although its controller derives from the Saturn's 3D Control Pad), and operates in much the same way as the Saturn (and PlayStation) does, with a configurable settings and memory management accessed through a BIOS screen.

The Dreamcast uses a proprietary format of storage called GD-ROMs for games in order to foil software pirates, a strategy that ultimately backfired when the first run of discs had a high rate of defects. The format was also cracked fairly quickly (and in some cases, the pirated games were released before the legitimate versions). Sega largely had themselves to blame for the high levels of Dreamcast piracy—their use of the GD-ROM format was completely undermined by the console's support for the Mil-CD format, which allowed the console to boot from a standard CD-R. Mil-CD support was removed from the final Dreamcast revisions toward the end of the console's life.

The GD-ROM format also put the console at a disadvantage when competing against the PlayStation 2 - the PS2 used DVDs, and could therefore run DVD videos making it an inexpensive DVD player as well as a video game console. DVD-ROMs also have more stoage space, allowing for bigger games (though the initial run of PS2 games used a blue CD-ROM format).

The Dreamcast was the first video game console to ship with a built-in 56k modem, with broadband adapters being made available later on in certain regions. This allowed the system to connect to the internet using a custom, fully-functional web browser and e-mail client. Many games released for the Dreamcast shipped with online play modes, the most popular being Phantasy Star Online and the Sega Sports lineup (now published under the ESPN label). Although other consoles before the Dreamcast had network gaming support, such as the Sega Saturn's NetLink and the Sega Mega Drive's XB∀ND, the Dreamcast was the first game console to include this ability out of the box and is therefore considered the first internet-enabled home game system.

The Dreamcast has a modest hacking enthusiast community. The availability of Windows CE software development kits on the Internet—as well as ports of Linux (LinuxDC) and dreamcast NetBSD operating systems to the Dreamcast—gave programmers a selection of familiar development tools to work with, even though they do not really support the high speed graphics. A homebrew minimal operating system called Kallistios offers support for most hardware, while not offering multi-tasking, which is superfluous for games. Many emulators and other tools (MP3, DivX players, and image viewers) have been ported to or written for the console, taking advantage of the relative ease with which a home user can write a CD which is bootable by an unmodified Dreamcast.

Sega released an arcade board, using the same technology as the Dreamcast, called Sega NAOMI, leading to many Dreamcast-exclusive games with a high level of arcade quality. They later packaged the Dreamcast into an arcade board as the Atomiswave.

Though the Dreamcast was officially discontinued in early 2001, commercial games were still developed for it and worldwide software support continued until 2002, terminating in the USA with the February 12th release of NHL 2K2, and in Europe with Cannon Spike and Freestyle Scooter on May 3. In Japan, software support continued for much longer. On February 24, 2004, Sega released its final Dreamcast game, Puyo Puyo Fever. The final new third party game for the system was Karous, released on March 8, 2007, and the final official release was a reprint of the 2003 title Border Down released exclusively through the Messe Sanoh store on January 17, 2008.

Models

See also: Dreamcast consoles

Japanese Dreamcasts can be identified by the triangle at the front of the unit. Though the power LED is identical across all regions, the piece of plastic attached to the lid of the Japanese model is transparent, while in North America it is grey.

For a full list of special edition Dreamcasts, see Special Dreamcast Models.

Technical Specifications

CPU

  • CPU: Hitachi SH-4 (RISC, 2‑way Superscalar) [1][2]
    • Operating frequency: 200 MHz
    • Units: 128‑bit SIMD vector unit with graphic functions, 64‑bit floating‑point unit, 32‑bit fixed‑point unit
    • 128‑bit SIMD @ 200 MHz: Vector unit, geometry processor, graphic functions, DMA controller, interrupt controller [3]
    • 128‑bit graphic computational engine: Calculates geometry and lighting of polygons, creates display lists of polygons for tiling, DMA allows SH4 access to VRAM and PowerVR2 access to Main RAM, store queue mechanism (allowing high‑speed packet transfers between Main RAM and VRAM) [4]
    • Bus width: 128‑bit internal, 64‑bit external
    • Bandwidth: 3.2 GB/s internal, 1.6 GB/s external
    • Fixed‑point performance: 360 MIPS
    • Floating‑point performance: 1.4 GFLOPS (7 MFLOPS per 16 MB/s)
    • Geometry performance: More than 10 million polygons/sec, with lighting calculations (140 FLOPS per polygon)

Graphics

Graphical specifications of the Dreamcast: [5][4][6]

  • GPU: 2 core processors (SH‑4 SIMD, PowerVR2)
    • Core units: 5 units (SH‑4 SIMD, 4 PowerVR2 cores)
  • GPU Geometry Processor: Hitachi SH‑4 SIMD @ 200 MHz
  • GPU Rasterizer: NECVideoLogic PowerVR2 CLX2 (PVR2DC/HOLLY) @ 100 MHz
  • PowerVR2 Cores: Tile Accelerator (TA), Image Synthesis Processor (ISP), Texture & Shading Processor (TSP), RAMDAC
    • TA: Tile renderer, partitions infinite strip polygon data, divides polygons into tiles, performs tile clipping, generates object lists, retrieves display lists from SH4 (through store queues and DMA), generates ISP/TSP parameters
    • ISP: Rasterizer, depth‑sorting, RLE tile/polygon compression, parallel‑processing of tiles/polygons at high speeds (1 clock cycle per vector, 32 pixels per clock cycle)
    • TSP: Shader and texture‑mapping unit, avoids shading/texturing overdrawn pixels/tiles and back‑facing polygons to maximize bandwidth for on‑screen pixels/tiles and front‑facing polygons
    • RAMDAC: 230 MHz [7]
  • PowerVR2 Capabilities:
  • Display Resolution: 320×240 to 800×608 pixels, interlaced and progressive scan, TV and VGA
    • Internal resolution: 320×240 to 1600×1200 pixels [7]
  • Color Depth: 16‑bit RGB to 32‑bit ARGB, 65,536 colors (16‑bit color) to 16,777,216 colors (24‑bit color) with 8‑bit (256 levels) alpha blending, YUV and RGB color spaces, color key overlay [13]
  • Framebuffer:
    • Full framebuffer: 320×240×16‑bit (150 KB) to 1600×1200×32‑bit (7500 KB)
    • Strip/Tile buffer: 32×32×16‑bit (4 KB) to 32×1024×32‑bit (256 KB) [4]
  • Geometry Performance: 23 million vertices/sec (60 FLOPS per polygon) [14]
  • Polygon Geometry: Effective performance, including overdrawn and back‑facing polygons not drawn on screen
    • 11 million polygons/sec (130 FLOPS per polygon)
    • More than 10 million polygons/sec: Lighting (140 FLOPS per polygon) [1]
  • Rendered On‑Screen Polygons: Front‑facing polygons drawn on screen, not including overdrawn and back‑facing polygons (including them, effective performance is more than than 10 million polygons/sec) [1][15]
    • 7 million polygons/sec: Lighting, textures, shadows,[7] trilinear filtering [16]
    • 6 million polygons/sec: Lighting, textures, trilinear filtering, Gouraud shading (243 FLOPS per polygon)
    • 3.3 million polygons/sec: Lighting, textures, trilinear filtering, Gouraud shading, bump mapping (430 FLOPS per polygon) [17]
  • Rendering Fillrate: [1][4]
    • 3.2 GPixels/s: Opaque polygons (32 pixels per clock cycle)
    • 200–500 MPixels/s: Average fillrate [18]
    • 100 MPixels/s: Translucent polygons with maximum hardware sort depth of 60 (1 pixel per clock cycle)
    • 100 MPixels/s to 3.2 GPixels/s, depending on opacity/translucency of polygons (1–32 pixels per clock cycle) [6]
  • Texture Fillrate:
    • 200–500 MTexels/s: Effective fillrate (including overdrawn and back‑facing textures)
    • 100 MTexels/s: Front‑facing textures drawn on screen
  • VRAM: 8 MB (unified framebuffer/polygon/texture memory) [4][19]
    • Framebuffer: 4 KB to 7500 KB
    • Polygons: Up to 6511 KB (10 million polygons/sec, 32‑bit precision, 40 bytes per polygon)
    • Textures: Up to 8188 KB (63.8 MB with maximum compression)
    • Note: Main RAM can also be used to store textures and polygon display lists
  • Full Motion Video: MPEG decoding, video compression, 320×240 to 640×320 and 320×480 video resolutions, 3D polygons can be superimposed over FMV video [1]

Sound

Memory

  • System RAM: 26.125 MB
    • Main RAM: 16 MB SDRAM (Hyundai HY57V161610D)
      • Can be used for storing textures and polygon display lists, accessible by SH4 and PowerVR2 (via SH4 DMA) [4]
    • VRAM: 8 MB SDRAM (unified framebuffer/polygon/texture memory)
      • Accessible by Power VR2 and SH4 (via DMA and store queues)
    • Sound RAM: 2 MB SDRAM
    • GD-ROM buffer RAM: 128 KB [5]
  • System ROM: 2 MB [5]
  • Flash Memory: 128 KB [4]
  • Internal Processor Memory: 65,232 bytes (63.703 KB) [4]
    • SH4: 26,178 bytes (8 KB instruction cache, 16 KB data cache, 64 bytes store queue cache,[21] 1538 bytes registers)
    • PowerVR2: 6274 bytes (128 bytes ISP cache, 1 KB texture cache, 509 bytes fog table, 4093 bytes palette RAM, 256 bytes FIFO buffer, 264 bytes registers)
    • AICA: 32,780 bytes (32 KB sound registers, 8 bytes RTC registers,[5] 4 bytes FIFO buffer)
  • GD-ROM Drive: 12× maximum speed (when running in Constant Angular Velocity mode) [5][4]
    • Disc formats: GD‑ROM, CD‑ROM, CD‑DA, , Photo CD, Video CD, CD Extra, CD+G, CD+EG
    • Storage capacity: 1 GB per GD‑ROM, 656 MB per CD‑ROM

Bandwidth

  • System RAM Bandwidth: 1.8 GB/s [5]
    • SH4 <‑> Main RAM — 800 MB/s (64‑bit, 100 MHz)
    • PVR2 <‑> VRAM — 800 MB/s (64‑bit, 100 MHz, 7 ns) [22]
    • AICA <‑> Sound RAM — 132 MB/s (16‑bit, 66 MHz)
    • SH4 <‑> GD‑ROM buffer — 13.3 MB/s (16‑bit)
  • System ROM Bandwidth: 20 MB/s (16‑bit, 10 MHz)
  • Internal Processor Memory Bandwidth: 2.7 GB/s
    • SH4: 1.6 GB/s (64‑bit, 200 MHz)
    • PowerVR2: 800 MB/s (64‑bit, 100 MHz)
    • AICA: 256 MB/s (32‑bit, 67 MHz)
  • GD‑ROM Drive: 1.8 MB/s transfer rate, 250 milliseconds access time

BIOS

BIOS Revisions
BIOS Version Machine Download
1.004 Sega Dreamcast (Commercial-Early) 1.004 (Japan) (info) ("Jp_dc_1.004.7z" does not exist)
1.01d Sega Dreamcast (Commercial) 1.01d (North America) (info) ("Us_dc_1.01d.zip" does not exist)
1.01d (Europe) (info) ("Eu_dc_1.01d.zip" does not exist)
1.01d (Japan) (info) ("Jp_dc_1.01d.zip" does not exist)
1.011 Sega Dreamcast (HKT-0120 Devbox) 1.011 (HKT-0120 Devbox) (info) ("Jp_dc_1.011(dev).7z" does not exist)

Other Specifications

  • Operating Systems:
  • Inputs: Four ports that can support a digital and analog controller, steering wheel, joystick, keyboard, mouse, and more
  • Dimensions: 189mm x 195mm x 76mm (7 7/16" x 7 11/16" x 3")
  • Weight: 1.9kg (4.4lbs)
  • Modem: Removable; Original Asia/Japan model had a 33.6 Kbytes/s; models released after 9 September 1999 had a 56 Kbytes/s modem
  • Sega Dreamcast Broadband Adapter: these adapters are available separately and replace the removable modem
    • HIT-400: "Broadband Adapter", the more common model, this used a RealTek 8139 chip and supported 10/100mbit
  • HIT-300: "Lan Adapter", this version used a Fujitsu MB86967 chip and supported only 10mbit
  • Storage: "Visual Memory Unit" (VMU) 128 Kb removable storage device
  • Input devices: (4 custom controller ports)
  • Output devices:
  • Add-ons:

History

Main article: History of the Sega Dreamcast

Launch Titles

Japan

North America

Europe

[23]

Gallery

Hardware Diagrams

Logos

Promotional Material

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Television Advertisements

References

Sega Home Video Game Systems
83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11
SG-1000 SG-1000 II Mega Drive Mega Drive II
SC-3000 Mega-CD Mega-CD II Genesis 3
Sega Mark III 32X Dreamcast
Master System Master System II
AI Computer Game Gear
Saturn
Pico Beena


Sega Dreamcast
Topics Technical specifications (Hardware comparison) | History (Development | Release | Decline and legacy | Internet) | List of games | Magazine articles | Promotional material | Merchandise
Hardware Japan (Special) | Western Europe | Eastern Europe | North America | Asia | South America | Australasia | Africa
Add-ons Dreamcast Karaoke | Dreameye
Controllers Controller | Arcade Stick | Fishing Controller | Gun (Dream Blaster) | Race Controller | Maracas Controller (Third-party) | Twin Stick | Keyboard | Mouse | Third-party
Controller Add-ons Jump Pack (Third-party) | Microphone | VMU (4x Memory Card | Third-party)
Development Hardware Dev.Box | Controller Box | Controller Function Checker | Sound Box | GD-Writer | C1/C2 Checker | Dev.Cas | GD-ROM Duplicator
Online Services/Add-ons Dreamarena | SegaNet | WebTV for Dreamcast | Modem | Modular Cable | Modular Extension Cable | Broadband Adapter | Dreamphone
Connector Cables Onsei Setsuzoku Cable | RF Adapter | Scart Cable | S Tanshi Cable | Stereo AV Cable | VGA Box

Dreamcast MIDI Interface Cable | Neo Geo Pocket/Dreamcast Setsuzoku Cable | Taisen Cable

Misc. Hardware Action Replay CDX | Code Breaker | Kiosk | MP3 DC | MP3 DC Audio Player | Official Case | Treamcast
Third-party accessories Controllers | Controller converters | Miscellaneous
Unreleased Accessories DVD Player | Zip Drive | Swatch Access for Dreamcast | VMU MP3 Player
Arcade Variants NAOMI | Atomiswave | Sega Aurora