Sega Model 2

From Sega Retro

Model2 cpu.jpg
Sega Model 2
Manufacturer: Sega
Variants: Model 2A-CRX, Model 2B-CRX, Model 2C-CRX
Add-ons: DSB1/DSB2 (Model 2C-CRX)
Release Date RRP Code

The Sega Model 2 is an arcade system board originally debuted by Sega in 1993 as a successor to the Sega Model 1 board. It is an extension of the Model 1 hardware, most notably introducing the concept of texture-mapped polygons, allowing for more realistic 3D graphics for its time. The Model 2 board was an important milestone for the arcade industry, and helped launch several key arcade franchises of the 1990s, including Daytona USA, Virtua Cop, Sega Rally Championship, Dead or Alive, Virtua Striker, Cyber Troopers Virtual-On and The House of the Dead.

The Model 2's development was led by famed Sega AM2 game designer Yu Suzuki. Sega engineered the Model 2 with help from Fujitsu and GE Aerospace (acquired by Martin Marietta in 1993, now part of Lockheed Martin). Sega developed the polygon geometry engine in-house, using Fujitsu coprocessors, combined with GE Aerospace's expensive texture-mapping technology,[1] which Suzuki's team condensed into a more affordable chipset. The arcade board debuted along with Daytona USA, a game which was finished and copyrighted in 1993, and debuted at the JAMMA arcade show in August 1993.[2]

There are four versions of the system: the original Model 2, and the Model 2A-CRX, Model 2B-CRX and Model 2C-CRX variants. Model 2 and 2A-CRX used a custom DSP with internal code for the geometrizer, while 2B-CRX and 2C-CRX used well documented DSPs and uploaded the geometrizer code at startup to the DSP. The Model 2 was succeeded in 1996 by the Sega Model 3, which in turn was succeeded by the Sega NAOMI, Sega Hikaru and Sega NAOMI 2.

History

It was a further advancement of the earlier Model 1 system. The most noticeable improvement was texture mapping, which enabled polygons to be painted with bitmap images, as opposed to the limited monotone flat shading that Model 1 supported. The Model 2 also introduced the use of texture filtering and texture anti-aliasing,[3] as well as trilinear filtering.[4] It was the most powerful game system in its time, equivalent to the power of a PC graphics card in 1998, five years after the Model 2's release.[4]

The hardware was designed by Sega AM2's Yu Suzuki and engineered by his Sega AM2 team.[5] The polygon geometry engine was developed in-house at Sega,[1] using Fujitsu DSP coprocessors that were modified with Sega's custom microcode for hardware T&L capabilities;[6] it would be years before hardware T&L would appear on consumer home systems.

Suzuki stated that the Model 2's texture mapping chip originated "from military equipment from Lockheed Martin, which was formerly General Electric Aerial & Space's textural mapping technology. It cost $2 million dollars to use the chip. It was part of flight-simulation equipment that cost $32 million. I asked how much it would cost to buy just the chip and they came back with $2 million. And I had to take that chip and convert it for video game use, and make the technology available for the consumer at 5,000 yen ($50)" ($84 in 2014) per machine. He said "it was tough but we were able to make it for 5,000 yen. Nobody at Sega believed me when I said I wanted to purchase this technology for our games."[5] Suzuki stated that, in "the end," it "was a hit and the industry gained mass-produced texture-mapping as a result." For Virtua Fighter 2, he also utilized motion capture technology, introducing it to the game industry.[7]

There were also issues working on the new CPU,[5] the Intel i960-KB, which had just released in 1993[8]. Suzuki stated that when working "on a brand new CPU, the debugger doesn't exist yet. The latest hardware doesn't work because it's full of bugs. And even if a debugger exists, the debugger itself is full of bugs. So, I had to debug the debugger. And of course with new hardware there's no library or system, so I had to create all of that, as well. It was a brutal cycle."[5]

In a late 1998 interview, Read3D's Jon Lenyo, a former employee of GE Aerospace (later Lockheed Martin), stated that Sega's development for the Model 2 can be traced back as early as November 1990, when he and other GE Aerospace employees visited Sega and demonstrated the trilinear texture filtering and shading capabilities of their technology. As Sega was already working on the Sega Model 1 internally, they eventually incorporated GE Aerospace's technology into the Model 2.[4]

Despite its high price tag of around $15,000[4] (equivalent to $24,489 in 2014), the Model 2 platform was very successful. It featured some of the highest grossing arcade games of all time: Daytona USA, Virtua Fighter 2, Cyber Troopers Virtual-On, The House of the Dead, and Dead or Alive, to name a few. Sega sold 65,000 units of the Model 2 annually,[4] and eventually sold over 130,000 units by 1996, amounting to over $1.95 billion revenue from hardware cabinet sales (130,000 units[9][10] at $15,000 each),[4][11] equivalent to over $3.18 billion in 2014, making it one of the best-selling arcade systems of all time.

According to Yu Suzuki, the Sega Model 2B-CRX arcade system board developed for Fighting Vipers "has a slightly faster processing speed" and "a higher response to displaying more polygons".[12]

Technical Specifications

Model 2 Specifications

Sound

Graphics

Graphical specifications of the Sega Model 2:[18][13][1]

Memory

  • Memory: Up to 62 MB (10,881 KB main, 35,460 KB video, 16,960 KB audio, 18 KB other)
  • System RAM: 9776 KB (9.546875 MB)[18]
  • Internal processor memory: 36.75 KB
    • CPU cache: 768 bytes[15]
    • TGP internal RAM: 36 KB (6 KB per TGP)[20]
  • Game ROM: Up to 54.25 MB

Bandwidth

  • System RAM bandwidth: 974 MB/s
    • Main RAM bandwidth: 112 MB/s
      • i960: 100 MB/s (32‑bit, 25 MHz)
      • Z80: 12 MB/s (2× 8‑bit, 8/4 MHz)
    • VRAM bandwidth: 883.34066 MB/s[14][21]
      • TGP: 384 MB/s (6× 32‑bit, 16 MHz)[32]
      • Video Board: 499.34066 MB/s
        • 315‑5292 & 315‑5644: 30.769232 MB/s (2× 16‑bit, 7.692308 MHz)[33]
        • 315‑5645: 28.571428 MB/s (16‑bit, 14.285714 MHz)[34]
        • 315‑5646 & 315‑5647: 400 MB/s (2× 32‑bit, 50 MHz)
        • 315‑5712: 40 MB/s (8‑bit, 40 MHz)[35]
    • Audio RAM bandwidth: 20 MB/s (16‑bit, 10 MHz)
  • Internal processor bandwidth: 484 MB/s
    • CPU cache: 100 MB/s (32‑bit, 25 MHz)
    • TGP internal RAM: 384 MB/s (6× 32‑bit, 16 MHz)
  • Game ROM bandwidth: 933–1000 MB/s (5× 32‑bit)[14][13]
    • EPROM: 133–200 MB/s (32‑bit, 33–50 MHz, 20–30 ns)[36][37]
    • MROM: 800 MB/s (4× 32‑bit, 50 MHz)

Model 2A-CRX

Model 2A-CRX, released in 1994, featured upgraded sound capabilities and increased ROM capacity:

  • Sound CPU: Motorola 68000 @ 12 MHz (16/32‑bit instructions @ 2.1 MIPS)
  • Sound chip: Yamaha SCSP
    • PCM channels: 56
    • PCM sample ROM: Up to 16 MB
    • PCM quality: 16‑bit depth, 44.1 kHz sampling rate (CD quality)
    • SCSP features: 128-step DSP, 32 PCM/FM/MIDI/LFO channels
  • Memory: Up to 142 MB (35,969 KB main, 90,244 KB video, 16,960 KB audio, 2064 KB other)
    • System RAM: 9776 KB (9.546875 MB)
      • Main RAM: 1152 KB (1.125 MB)
      • VRAM: 5984 KB (5.84375 MB)
      • Audio RAM: 576 KB
      • Other RAM: 2064 KB (2.015625 MB)
    • Internal processor memory: 36.75 KB
      • CPU cache: 768 bytes
      • TGP internal RAM: 36 KB
    • Game ROM: Up to 132.25 MB (34 MB main, 82.25 MB video,[38] 16 MB audio)

Model 2B-CRX

Model 2A-CRX, released in 1995, featured upgraded geometry engine DSP coprocessors and increased VRAM:[18]

  • GPU Geometry Engine DSP coprocessors: 2× ADSP-21062 SHARC @ 40 MHz[39]
    • Coprocessor abilities: Floating decimal point operation function, axis rotation operation function, 3D matrix operation function, SOC, ALU, T&L
    • Floating-point units: 32/40‑bit operations, 240 MFLOPS peak (120 MFLOPS each), 160 MFLOPS sustained
    • Fixed-point arithmetic: 32‑bit instructions @ 80 MIPS (40 MIPS each)
    • Data bus width: 96‑bit (48‑bit each)
    • DMA controllers: 20 DMA channels (10 channels each), 480 MB/s transfer rate (240 MB/s each)
  • Fillrate:
    • Rendering: 120 MPixels/s (2 MPixels per frame)
    • Texturing: 120 MTexels/s
  • Geometry calculations: 160 MFLOPS
    • Vertex transformations: 4.7 million vertices/sec[n 11]
    • Polygon transformations: 1.6 million triangles/sec,[n 12] 1.2 million quads/sec[n 13]
    • Lighting calculations: 1.2 million triangles/sec,[n 14] 900,000 quads/sec[n 15]
  • Polygon rendering performance: 120 MPixels/s, 120 MTexels/s
    • 800,000 polygons/sec: Lighting, textures, 150-texel textures
    • 600,000 polygons/sec: Lighting, textures, 200-texel textures
  • Memory: Up to 150.21 MB (35.125 MB main, 99,332 KB video, 16,960 KB audio, 18 KB other)
    • System RAM: 18,388 KB (17.957031 MB)[13]
      • Main RAM: 1152 KB (1.125 MB)
      • VRAM: 14,596 KB (1.5 MB framebuffer VRAM, 8228 KB coprocessor buffer SRAM/SDRAM, 4 MB texture SRAM/SDRAM, 64 KB luma, 32 KB geometry, 576 KB tiles, 64 KB colors)
      • Audio RAM: 576 KB
      • Other RAM: 2064 KB (2.015625 MB)
    • Internal processor memory: 512.75 KB
      • CPU cache: 768 bytes
      • DSP internal RAM: 512 KB SRAM (256 KB per DSP)[39]
    • Game ROM: Up to 132.25 MB (34 MB main, 82.25 MB video, 16 MB audio)
  • System RAM bandwidth: 1.111 GB/s
    • Main RAM bandwidth: 112 MB/s
    • VRAM bandwidth: 979.34066 MB/s
      • SHARC: 480 MB/s (2x 240 MB/s)[40]
      • Video Board: 499.34066 MB/s
    • Audio RAM bandwidth: 20 MB/s

Model 2C-CRX

Model 2A-CRX, released in 1996, featured an upgraded GPU chipset and optional MPEG sound boards:

  • GPU coprocessors: 2× Fujitsu TGPx4 MB86235 @ 40 MHz[18][41]
    • Coprocessor abilities: Geometry Engine DSP, Z-sorters, clipping, hardware renderers, floating decimal point operation function, axis rotation operation function, 3D matrix operation function, ALU, DMA controllers, T&L
    • Floating-point units: 32/40‑bit operations @ 160 MFLOPS (80 MFLOPS each)
    • Fixed-point arithmetic: 32/64‑bit instructions @ 240 MIPS (120 MIPS each)
    • Bus width: 192‑bit (96‑bit each; 64‑bit SDRAM, 32‑bit SRAM)
  • Graphical features: Gouraud shading, hidden surface, Z-buffering, point sampling, bilinear filtering, trilinear filtering[42]
  • Fillrate:[41]
    • Rendering: 190 MPixels/s (95 MPixels/s per GPU)
    • Texturing: 190 MTexels/s (95 MTexels/s per GPU)
  • Polygon rendering performance:[41]
    • 800,000 polygons/sec: Lighting, textures, flat shading[n 16]
    • 600,000 polygons/sec: Lighting, textures, flat shading, Z-sorting[n 17]
    • 490,000 polygons/sec: Lighting, textures, Gouraud shading[n 18]
    • 366,000 polygons/sec: Lighting, textures, Gouraud shading, Z-sorting[n 19]
  • Optional MPEG sound board: DSB1
    • Sound CPU: Zilog Z80 (8/16‑bit instructions)
    • Sound chip: NEC µD65654GF102
  • Optional MPEG sound board: DSB2
    • Sound CPU: Motorola 68000 (16/32‑bit instructions)
    • Sound chip: NEC µD65654GF102

List of Games

Model 2

Model 2A-CRX

Model 2B-CRX

Model 2C-CRX

Other

Gallery

Notes

  1. [i960: 13.6 MFLOPS
    TGP: 96 MFLOPS (6x 16 MFLOPS) i960: 13.6 MFLOPS
    TGP: 96 MFLOPS (6x 16 MFLOPS)]
  2. [34 FLOPS (32 adds/multiplies,[26] 1 divide)[27] per vertex 34 FLOPS (32 adds/multiplies,[26] 1 divide)[27] per vertex]
  3. [99 FLOPS (96 adds/multiplies,[26] 3 divides)[27] per triangle 99 FLOPS (96 adds/multiplies,[26] 3 divides)[27] per triangle]
  4. [132 FLOPS (128 adds/multiplies, 4 divides) per quad 132 FLOPS (128 adds/multiplies, 4 divides) per quad]
  5. [131 FLOPS (128 adds/multiplies,[26] 3 divides) per triangle 131 FLOPS (128 adds/multiplies,[26] 3 divides) per triangle]
  6. [164 FLOPS (160 adds/multiplies,[26] 4 divides) per quad 164 FLOPS (160 adds/multiplies,[26] 4 divides) per quad]
  7. [201 FLOPS per triangle[26] 201 FLOPS per triangle[26]]
  8. [268 FLOPS per quad[26] 268 FLOPS per quad[26]]
  9. [347 cycles (268 geometry FLOPS, 40 RAM cycles, 39 raster FLOPS) 3 FLOPS/scanline per polygon,[29][30] 3 cycles per pixel, 359 cycles per 4-scanline polygon, 455 cycles per 32-pixel polygon 347 cycles (268 geometry FLOPS, 40 RAM cycles, 39 raster FLOPS) 3 FLOPS/scanline per polygon,[29][30] 3 cycles per pixel, 359 cycles per 4-scanline polygon, 455 cycles per 32-pixel polygon]
  10. [695 cycles per 100-texel polygon
    • Gouraud shading: 455 cycles per 32-pixel polygon
    • Texture mapping: 128 cycles per 32-texel texture: 2 block moves, 2 cycles per texel (2 bytes per texel)
    • Texture mapping: 112 divide cycles per 32-texel polygon: 56 divides per 100-texel polygon, 24 vertex divide cycles per polygon (12 divides per polygon), 64 texel divide cycles per 32-texel polygon (32 divides, 1 divide per texel)[31] 695 cycles per 100-texel polygon
    • Gouraud shading: 455 cycles per 32-pixel polygon
    • Texture mapping: 128 cycles per 32-texel texture: 2 block moves, 2 cycles per texel (2 bytes per texel)
    • Texture mapping: 112 divide cycles per 32-texel polygon: 56 divides per 100-texel polygon, 24 vertex divide cycles per polygon (12 divides per polygon), 64 texel divide cycles per 32-texel polygon (32 divides, 1 divide per texel)[31]]
  11. [34 FLOPS per vertex 34 FLOPS per vertex]
  12. [99 FLOPS per triangle 99 FLOPS per triangle]
  13. [132 FLOPS per quad 132 FLOPS per quad]
  14. [131 FLOPS per triangle 131 FLOPS per triangle]
  15. [164 FLOPS per quad 164 FLOPS per quad]
  16. [200 FLOPS per polygon, 266 IPS per polygon 200 FLOPS per polygon, 266 IPS per polygon]
  17. [272 FLOPS per polygon 272 FLOPS per polygon]
  18. [326 FLOPS per polygon 326 FLOPS per polygon]
  19. [438 FLOPS per polygon 438 FLOPS per polygon]

References

  1. 1.0 1.1 1.2 File:NextGeneration US 11.pdf, page 16
  2. File:EGM US 051.pdf, page 222
  3. IGN PRESENTS THE HISTORY OF SEGA (page 8)
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 http://www.thg.ru/smoke/19991022/print.html
  5. 5.0 5.1 5.2 5.3 The Disappearance of Yu Suzuki: Part 1 (1UP)
  6. 6.0 6.1 6.2 TGP (MAME)
  7. Yu Suzuki recalls using military tech to make Virtua Fighter 2
  8. 8.0 8.1 File:80960KB datasheet.pdf
  9. http://archive.today/XN3rz
  10. http://tinyurl.com/nyb7y3s
  11. Early concept of Daytona USA at Summer CES 1993
  12. File:SSM_UK_02.pdf, page 21
  13. 13.0 13.1 13.2 13.3 13.4 https://github.com/mamedev/mame/blob/master/src/mame/drivers/model2.cpp
  14. 14.0 14.1 14.2 14.3 14.4 14.5 http://www.tvspels-nostalgi.com/pcb_sega.htm
  15. 15.0 15.1 File:I960 datasheet.pdf
  16. http://pdf.datasheetarchive.com/indexerfiles/Scans-068/DSA2IH00225160.pdf
  17. File:ST-077-R2-052594.pdf
  18. 18.0 18.1 18.2 18.3 18.4 18.5 https://github.com/mamedev/mame/blob/master/src/mame/video/model2.cpp
  19. Sega Model 2 ROM Dump
  20. 20.0 20.1 File:MB86232 datasheet.pdf
  21. 21.0 21.1 Sega Model 2 Video Board
  22. Sega 16‑Bit Common Hardware, MAME
  23. File:EGM US 059.pdf, page 68
  24. File:VirtuaFighter2 Model2 Flyer.pdf, page 2
  25. 25.0 25.1 http://www.gamezero.com/team-0/whats_new/past/news9504.html
  26. 26.0 26.1 26.2 26.3 26.4 26.5 Design of Digital Systems and Devices (pages 95-97)
  27. 27.0 27.1 3D Polygon Rendering Pipeline (page 50)
  28. File:DaytonaUSA Model2 Flyer.pdf, page 2
  29. Transformation Of Rendering Algorithms For Hardware Implementation (page 53)
  30. File:32XUSHardwareManual.pdf, page 76
  31. State of the Art in Computer Graphics: Visualization and Modeling (page 110)
  32. File:TC5588P datasheet.pdf
  33. File:TC518128CPL datasheet.pdf
  34. File:MB84256A datasheet.pdf
  35. http://pdf.datasheetarchive.com/datasheetsmain/Datasheets-39/DSA-764435.pdf
  36. File:AM27C1024 datasheet.pdf
  37. File:MX27C1024 datasheet.pdf
  38. http://mamedb.com/game/dynamcop
  39. 39.0 39.1 File:ADSP-2106 datasheet.pdf
  40. File:ADSP-2106 datasheet.pdf, page 4
  41. 41.0 41.1 41.2 File:3DGraphicsProcessorChipSet.pdf
  42. File:3D-CG System with Video Texturing.pdf


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