Sega Saturn

Sega Saturn
Manufacturer: Sega
Variants: Sega Titan Video
Add-ons: Backup Memory, PriFun, Video CD Card, Extended RAM Cartridge, ROM Cartridge
Release Date RRP Code JP 1994-11-22 ¥80,80080,800 HST-0001 US 1995-05-11 $399.99399.99 MK-80001 EU 1995-07-08 DE 1995-07-07 DM 699699 ES 1995-07-07 79,900Ptas79,900 FR 1995-07 3,390F3,390 AU 1995-07-08 BR 1995-08-30 R$899.99899.99 KR 1995-11-10 ₩550,000550,000 SPC-SATURN AS 1994

The Sega Saturn (セガサターン), is a video game console manufactured by Sega and was the successor to the Sega Mega Drive/Genesis (as opposed to add-ons such as the Sega 32X and Mega-CD). Initially released in 1994, the Saturn was a 32-bit compact disc-based system, and was a key player in what is now widely known as the fifth generation of video game consoles. The Saturn was first released on November 22, 1994 in Japan, May 11, 1995 in North America, and July 8, 1995 in Europe.

Depending on where you live, the Saturn could be described as either Sega's most successful console of all time (Japan) or one of their biggest commercial failures (North America). Despite being powerful for its time, its complex hardware and inability to meet rapidly evolving consumer expectations and demands put it in a distant third place in the Western world, but a combination of 2D sprite games, 3D arcade ports and strong marketing campaigns made the Saturn the most successful Sega console in Japan. Estimates for the total number of Saturns sold worldwide range from 9.5 million to 17 million.

The Saturn's main competitors were Sony's PlayStation released just a week after the Saturn in Japan, and the Nintendo 64 from September 1996. Its arcade counterpart was the Sega Titan Video (ST-V) system. It was succeeded by the Sega Dreamcast in late 1998.

Hardware

The Sega Saturn is the successor to the Mega Drive, though as a video game system it is almost entirely different. It is a "32-bit" console, marketed in such a way that it appeared to be an evolution of the "16-bit" era of video gaming dominated by the Mega Drive and Super NES (which in turn succeeded the "8-bit" Master System and NES, respectively).

This description, however, was initially fabricated - Sega of Japan originally claimed the Saturn was a "64-bit" console and some within Sega even chose to call it an "128-bit" machine, a number arrived at by cumulating processors rather than simply picking the main CPU. Alternatively some areas of Sega simply went down the "multi-processor" route, refusing to get drawn into the perceived differences between 32-bit and 64-bit. This was incidentally the last video game generation where these so-called "bit wars" were considered to matter.

The system uses CD-ROMs as its primary choice of media. Though it contains a cartridge slot, this is not used for games, but rather backup memory or RAM cartridges. The former was to extend the space for save games beyond that of the Saturn's internal memory, while the latter was used to augment the Saturn's limited memory and to avoid long CD load times.

The Saturn has two controller ports, and the standard Saturn controller builds on that seen in the six button Sega Mega Drive controller. It adds two shoulder buttons, first seen on the Super NES controller, bringing the amount of buttons up to nine. The 3D Control Pad, released later with NiGHTS into Dreams, would supply the console with an analogue stick and analogue shoulder buttons, the latter later being used in the Sega Dreamcast before being adopted by Nintendo and Microsoft for their GameCube and Xbox consoles, respectively.

The Sega Saturn hardware combined features from several Sega arcade systems. It has a multi-processor system, like arcade machines. Its geometry engine consists of three DSP math processors, two inside both Hitachi SH-2 CPU and one inside the SCU, which were all intended to be programmed in parallel using complex assembly language, similar to how Sega programmed 3D arcade games at the time.

The VDP1 combined features from the Sega System 32 and the Sega Model series, with a quad polygon engine based on the Model 1, and texture mapping capability based on the Model 2 and System 32. The VDP1 is capable of drawing more polygons than the Model 1, but less than the Model 2. The Saturn was also influenced by the Sega Model 1's use of a separate graphics processor for the 2D backgrounds (based on the Sega System 24). The quad polygons are drawn with edge anti‑aliasing (for smoother edges), forward texture mapping (a form of perspective correction), bilinear approximation (reduces texture warping), and medium polygon accuracy (resulting in seamless polygons).

The Saturn's VDP2 was based on Sega System 32 technology (an evolution of Super Scaler technology), used for both 2D backgrounds and 3D planes; the latter can be manipulated as polygon objects. The VDP2's tiled infinite plane engine uses tilemap compression and a form of scanline/tiled rendering to draw large, detailed, 3D texture-mapped infinite planes (for things such as grounds, seas, walls, ceilings, skies, etc.), with perspective correction and a virtually unlimited draw distance (and capable of effects such as transparency, parallax scrolling, reflective water surfaces, fog/misting, fire, and heat haze), at a very high tile fillrate for its time.

The VDP2 draws 3D infinite planes as large as 4096×4096 pixels at 30 FPS, equivalent to a fillrate of over 500 MPixels/s, significantly larger than what any console or PC hardware were capable of with polygons at the time. It requires 1 million texture-mapped polygons/sec, with 500 pixels per polygon, to draw a texture-mapped 4096×4096 infinite plane at 30 FPS; the Dreamcast was the first home system capable of doing this with polygons, as it was the first home system that exceeded 500 MPixels/s polygon fillrate (using tiled rendering).

The Saturn was known for its difficult 3D development environment (especially for third-party developers), including its complex parallel processing hardware architecture, requiring familiarity with assembly language, lack of an operating system, and initial lack of C language support, useful development tools and graphics software libraries. Sega eventually provided DTS support for these features in late 1995. However, the C language development tools were not very well optimized for Saturn hardware, only tapping into a fraction of the Saturn's power, compared to assembly language which could tap into most of the Saturn's power. For example, the libraries did not use the SCU DSP, nor were they well-optimized for a multi-core CPU setup. Some of the advanced techniques used by Sega's first-party AM studios did not become available until the introduction of SGL (Saturn Graphics Library).

Only a handful of developers were able to squeeze most of the power out of the second SH-2 CPU, and even fewer utilized the SCU DSP, as its assembly code was more complex than the SH-2. Assembly language was often used by Japanese and British developers, but rarely used by American developers who preferred C language. The VDP1 rendered quadrilateral polygons, which, despite being used by the most powerful gaming system at the time (Sega Model 2 arcade system), did not become industry standard for 3D graphics, compared to the more widely used triangle polygons.

The VDP2's tiled infinite plane engine, which could draw large 3D infinite planes with a much higher draw distance, texture details and fillrate than polygons at the time, was unfamiliar to most developers who relied on polygons to construct 3D planes. Sega's first-party 3D games often utilized both CPU, the DSP, and/or both VDP, but the hardware's complexity and difficult 3D development environment led to most third-party developers only utilizing a single CPU and the VDP1, just a portion of the Saturn's power, for 3D games. This was also partly due to the advanced techniques used by Sega's first-party studios being unavailable to third-party developers until the introduction of SGL. While the VDP2 was under-utilized for 3D games, it was frequently used for 2D games, where the VDP1 draws sprites and the VDP2 draws scrolling backgrounds.

Models

Main article: Sega Saturn consoles.

There are a variety of Sega Saturn models of different shapes and colours, as well as novelty units, such as the Game & Car Navi HiSaturn. Differences between systems are not as drastic as seen with the Sega Mega Drive - the same basic feature set and component designs were used throughout the console's lifespan in all regions.

HST-3200/HST-3210

First seen on launch day in Japan (1994-11-22), the HST-3200 (later revised and released as the HST-3210, although the differences aside from a BIOS update are not fully understood), commonly referred to as the "grey Saturn" (although during development it had a metallic finish), was the basis for all Sega Saturns released between the Japanese launch and early 1996. These Saturns use blue "oval" buttons, mounted to black plastic at the front of the unit, and have both "power" and "access" LEDs similar to the Sega Mega-CD.

The Saturn saw variants produced by Hitachi and Victor as the HiSaturn and V-Saturn respectively, though aside from altered BIOSes and aesthetics (and bundles/pricing) these do not deviate much from the Sega designs. Novelty value sees these models worth slightly more in pre-owned markets - fewer were produced than the Sega models, but compatibility rates are much the same.

Overseas versions are physically identical (save for region encoding), but use black plastic throughout.

• 

  Japanese model

• 

  Japanese V-Saturn model

• 

  Japanese HiSaturn model

• 

  Overseas model

• 

  Korean model

HST-3220

Released in March 1996, the HST-3220 stands as the only significant change to the Saturn's design, although functionality wise, the only feature omitted is the "access" LED seen in previous models. Reportedly the change in colour scheme was made to appeal to younger and female demographics.

These "white" Saturns likely cost less to produce (they were certainly sold for a lot less in Japan), but from a user perspective the change is largely negligible - the console is roughly the same size and has no problems running any Saturn software. White Saturns opt for grey "circle" power and reset buttons and a pink "open" button for lifting the lid.

It is rumoured, though not proven, that the HST-3220 has a faster disc reading time than its earlier counterparts, meaning quicker loading screens in games.

When brought overseas the console continued to be shipped only in black, although the North American and European models have different coloured buttons. In 1998 Sega started releasing special versions of these consoles with semi-transparent plastic under the "This is cool" brand - only 30,000 units were produced. Again aside from aesthetic differences the consoles are interchangeable.

Some of the Japanese colour designs were also brought to Brazil.

• 

  Japanese model

• 

  Japanese V-Saturn model

• 

  Japanese HiSaturn model

• 

  North American model

• 

  European model

• 

  Japanese "This is Cool" model

• 

  Japanese "Derby Stallion" model

• 

  Korean model

Revisions

Motherboards:

Note that the changes are all evolutional unless noted. If one revision, for example, integrates two ICs into one, all following ones have that too unless noted.

Board types used in Model 1: VA0 to 3

Board types used in Model 2: VA2 to 15

- VA0: Launch units, very first revision. CD Block is on a daughterboard, power supply mounted on top ("Type A"). Power led, access led, on/off and reset buttons, and the CD Tray open/close sensor are all separate. Uses ENR-007B drives (on some later units, ENR-007D). Very rarely they may have a Hitachi drive instead (JA00292).

- VA1: marked as "VA" on the motherboard, "VA1" on the controller board. Power supply is now bottom mounted ("Type B"). Every previous sub-board is now integrated to the motherboard, except the controller ports which are separated. This includes the CD Tray sensor which is now a very tall switch on the motherboards. Uses ENR-007D drives.

- VA2 & 3: Same form factor as VA1, but there are small changes to accompany the different CD Drive. The controller board is also a little different from VA1. VA2 is marked as VA SG, and VA3 is marked as VA SD. Type B power supply and ENR-011A drive. VA2 uses SG RAM for the main memory, VA3 uses SD RAM (hence their markings).

You'll notice that even revisions will all use SG RAM and the following odd one will use SD RAM, but the boards themselves are otherwise identical.

- VA4 & 5: Exactly the same as VA2 and 3, respectively, but in a model 2 case. The only difference is that a few components are removed (access led, memory reset button, resistor leading to both of them), since they are not used on model 2s anymore. Type B power supply, ENR-011A drive. Note that some model 2s are still marked as VA2 or 3 by the serial number, but they also have those components removed, perhaps some manufacturers failed to get the memo.

- VA6 to 9: Entirely new form factor, everything is in a single board from now on. Uses a new PLL chip (CY2292SC-45). Power supply has a different pinout ("Type C"). Uses ENR-013A drive. Some units may have a Sanyo 610-6185-30 drive instead. VA6 & 7 has the CD Block reduced to a single IC from the previous two, VA8 & 9 has them still separated. VA6 & 8 uses SG RAM, VA 7 & 9 uses SD RAM. VA9 seems to be using a much later design and is almost exclusive to PAL units, the only exception being the Hi-Saturn MMP-11. It also uses the old type PLL chip (315-5746, aka Hitachi HD49422).

- VA10 to 15: uses HQA-001A drive, sometimes rarely a Sanyo 610-6294-30 or a Sanyo 610-6473-30 instead. Sound block is now integrated to a single IC instead of two. Type C power supply. VA10 uses SG RAM, VA11 & 13 & 15 uses SD RAM. VA11 has a small extra daughter board to fix some design error. The function of that board is unknown. VA11+ boards have a different form factor DAC, VA10 uses the old one. VA12 and 14 were never produced. They would have been SG RAM counterparts to VA13 and 15. They may have been produced in extremely low quantities, so low that they haven't been spotted, but it is doubtful VA15 integrates the two SH-2 main cpus into a single IC.

Note: the integrated sound block has a bug in certain 68000 commands, this might be the same bug as the Genesis 3 suffers from as that one also has an integrated 68000 made by Yamaha. The result is that certain games are incompatible with these boards. The Japanese only releases of Space Harrier and Outrun are the only two that come to mind, and both have received second pressings that eliminate this bug and work in all machines equally. Metal Slug is rumored to be incompatible, but this appears to be false.

PAL Motherboards (only the main differences are listed, otherwise see above):

All PAL boards use different region & video output jumpers when compared to ntsc machines and use a 17.7344 Mhz master clock (NTSC units use 14.31818 Mhz). They also replace the c-sync output of the a/v out with a 9v connection, intended for SCART auto switching. On VA7+ boards, there is an extra power supply pin added to the entire machine just for that. C-sync is still there, just not wired into the a/v out, it can be restored with modding very easily (in case you are interested, the test point for c-sync is TP4 near the a/v out, on the bottom of the board).

- VA0 PAL - has extra jumpers to set the master clock divider (JP18 & 19), functional but unpopulated 50/60hz switch on the back (SW4).

- VA1 PAL - unpopulated 50/60hz switch on the back (SW4). There is a design snafu however, as it is still connected to the master clock divider select pin. Therefore the switch does not work on its own, you have to cut or raise+ground the PLL pin 1 for the switch to work.

- VA3 PAL - has extra jumpers to set the master clock divider (JP20 & 21), functional but unpopulated 50/60hz switch on the back (SW4).

- VA5 PAL - same as VA3 PAL.

- VA7 PAL - chronologically, this board was designed after VA9, likely to use up remaining stock of certain parts. Unlike NTSC boards, this still uses the old Hitachi PLL (315-5746), and its pin 1 is interconnected to the pal/ntsc and 50/60hz selection pins on the video encoder and the VDP2. So, for installing 50/60hz switches, you have to separate those accordingly. Has an extra fifth power supply pin for the a/v out (for SCART auto selection).

- VA9 - same notes apply as for VA7 PAL. This is an odd board in that it has no NTSC equivalent. Only the model 2 Hi-Saturn MMP-11 used VA9 boards, and they used the exact same boards as PAL machines, not counting the different jumper setup, master clock, power supply, etc.

- VA13 PAL - Has an extra fifth power supply pin for the a/v out (for SCART auto selection), but otherwise it seems to be identical to the NTSC boards.

It should be noted that no PAL board ever used SGRAM. The cause of this is unknown. Of course, the cause of using SGRAM in the first place is also unknown (and up to speculation - possible causes for both points include contractual obligations, shortage of one specific part, or a very good deal on SGRAM that made it worth to design two of each motherboards).

Power supplies:

Type A is for VA0 units, is mounted to the top, pinout is GND, GND, 3.3V, 5V, (empty pin), 9V. (5 pins total)

Type B is for VA 1 to 5 units, bottom mounted, pinout is GND, GND, 3.3V, 5V, 9V. (5 pins total)

Type C is for VA6+ units, bottom mounted, pinout is GND, GND, 5V, 5V (4 pins total). PAL units use a 5-pin variant of Type C power supplies, where the extra fifth pin is a 9V used exclusively in the a/v connector (for SCART auto switching). Later Asian units (that have a 220v power supply) most likely use that type of power supply too, with the 5th pin just not connected. In fact there are some USA machines that had a hole for the fifth pin but it was not connected to anything.

The moniker "Type A/B/C" is coined by the service manuals.

CD Drives:

20pin, VA0-1:

- JVC ENR-007B EMW10447-003E

- JVC ENR-007B EMW10447-004E

- JVC ENR-007D EMW10447-005E

- JVC ENR-007D EMW10447-006E

- Hitachi JA00292

These are all 20pin units. The Hitachi drive is rarely found in Japanese units, most commonly on early Hi-Saturns. They also seem to be exclusive to the SKC-1000 and SKC-1000C. There is a small difference in the microcontrollers used between ENR-007B and D.

21pin, VA 2-5:

- JVC ENR-011A EMW10589-002

- JVC ENR-011A EMW10589-003

These are the so-called 64pin drives. The -002 one seems to be used only in model 1s and the -003 only in model 2s, but it seems they are exchangeable.

21pin, VA6-9: - JVC ENR-013A EMW20035-002 610-6185-20 - Sanyo 610-6185-30 The JVC drive is most often referred to as the 32pin drive. The Sanyo drive may or may not come with an extra Trap Board, its function is unknown at this point.

21pin, VA10-15:

- JVC HQA-001A HQ100002-002 610-6294-20

- Sanyo 610-6294-30

- Sanyo 610-6473-30

Same as the above ones, but they all lack an oscillator and have a white border on the edges of the PCB. The Sanyo drive does not always comes with a trap board apparently.

Optical pickups used:

for EVERY JVC drive: Optima-6 (personally verified this for all drives)

for the Hitachi drive: HOP-6 (personally verified)

for Sanyo drives: SF-P101 is used in the 610-6185-30 (verified).

As you can see, there are three different Sanyo drives, from two different type of drive families. Modchip guides seem to take them all under the same umbrella, and that's why one guide may not work with one of the Sanyo drives (as it was meant for the other type).

Technical specifications

Processors

• Main CPU: 2× Hitachi SH-2 @ 28.63636 MHz
  • Configuration: Master/Slave
  • 2x CPU cores: 32‑bit RISC instructions/registers, 74.454536 MIPS (37.227268 MIPS each, 1.3 MIPS per MHz), up to 4 instructions/cycle (2 instructions/cycle per SH-2)
  • 2x DMA units: 2x DMAC (Direct Memory Access Controller), parallel processing
  • 4x internal fixed‑point math processors: 2x MULT multiplier DSP, 2x DIVU division units, parallel processing
    • 2x MULT multiplier DSP: 57.27272 MOPS fixed-point math (28.63636 MOPS per SH-2)
    • 2x DIVU division units: 16/32/64-bit division, 1,468,531 divides/sec
  • Bus width: 64‑bit (2× 32‑bit) internal, 32‑bit external
  • Word length: 32-bit
• System coprocesor: Custom Saturn Control Unit (SCU), with DSP for geometry processing and DMA controller for system control
  • System control processor: 32‑bit fixed‑point registers/instructions, interrupt controller, DMA controller, 3 DMA channels
  • Math coprocessor: Geometry DSP @ 14.31818 MHz, 32‑bit fixed‑point instructions, 6 parallel instructions per cycle, 85.90908 MIPS (6 MIPS per MHz)
• CD‑ROM CPU: Hitachi SH-1 32‑bit RISC processor @ 20 MHz (20 MIPS) (controlling the CD‑ROM)
  • Contains internal DAC and internal math processor
  • Bus width: 32‑bit internal, 16‑bit external
• Microcontroller: Hitachi HD404920 (4‑bit MCU) "System Manager & Peripheral Control" (SMPC) @ 4 MHz
  • RTC: 1 MHz (real‑time clock)
  • Instruction set: 4‑bit instructions, 890 ns per instruction, 1.123595 MIPS
  • Bus width: 10‑bit internal, 8‑bit external
• Optional MPEG Video CD Card:
  • MPEG Video decoder: Sega P/N 315-5765 (Hitachi HD814101FE)
  • MPEG Audio decoder: Hitachi HD814102F

Audio

• Sound processor: Yamaha SCSP (Saturn Custom Sound Processor) YMF292
  • Sound DSP: Yamaha FH1 DSP (Digital Signal Processor) @ 22.58 MHz (24‑bit, 128‑step, 4 parallel instructions)
  • Bus width: 24‑bit internal, 16‑bit external
• Sound CPU: Motorola 68EC000 (16/32‑bit CISC) sound processor @ 11.29 MHz (1.97575 MIPS)
  • Bus width: 16‑bit internal, 16‑bit external

Video

• Sega/Hitachi VDP1 @ 28.63636 MHz: Handles sprite/texture and polygon drawing
  • Bus width: 48‑bit (3x 16‑bit)
  • Word length: 16-bit
• Sega/Yamaha VDP2 @ 28.63636 MHz: Backgrounds, scrolling, handles background, scroll and 3D rotation planes
  • Bus width: 32‑bit
  • Word length: 32-bit
• Sony CXA1645M RGB‑Composite Video Encoder

Graphics

• Graphics pipeline:
  • 3 DSP geometry processors: 2× SH-2 DSP, SCU DSP
  • 2 VDP rendering processors: VDP1 for sprites/textures/polygons, VDP2 for planes/backgrounds/textures
• Video clock rate: 28.63636 MHz MHz (NTSC), 28.4375 MHz (PAL)
  • NTSC dot clock: 7.15909 MHz (lo-res), 14.31818 MHz (hi-res)
  • PAL dot clock: 7.109375 MHz (lo-res), 14.21875 MHz (hi-res)
• Display resolutions: 320×224 to 704×480 (see Resolutions)
  • NTSC overscan resolution: 453×263 (lo-res), 907×263 (hi-res)
  • PAL overscan resolution: 454×313 (lo-res), 908×313 (hi-res)
• Refresh rate: 30–60 Hz (NTSC), 25–50 Hz (PAL)
  • Maximum frame rate: 60 FPS (NTSC), 50 FPS (PAL)
• Color depth: 15-bit RGB to 32‑bit RGBA (24‑bit color with 8‑bit alpha transparency)
  • Color palette: 16,777,216 (VDP2), 32,768 (VDP1)
  • Colors on screen: 256 to 16,777,216 (VDP2), 256 to 32,768 (VDP1)
  • VDP2 colors per background: 16 colors (4-bit) to 16,777,216 colors (24-bit)
  • VDP1 colors per sprite/polygon: 16 colors (4-bit) to 32,768 colors (15-bit)
  • CLUT: Virtually unlimited number of CLUTs
• DSP geometry processing: 188 MIPS (million instructions per second)
  • Fixed-point operations: 114 MOPS (million operations per second)
  • Additions: 85 million adds/sec
  • Multiplications: 85 million multiplies/sec
  • 16-bit divisions: 5 million divides/sec
• Geometry calculations: 114 MOPS fixed-point calculations
  • Vertex transformations: 2,400,000 vertices/sec
  • Polygon transformations: 1,800,000 polygons/sec
  • T&L flat lighting: 800,000 polygons/sec
  • T&L Gouraud lighting: 700,000 polygons/sec
• Transmission bus bandwidth: 143 MB/s
  • DSP–VDP transmission bus: 114.54544 MB/s
  • VDP1–VDP2 transmission bus: 28.63636 MB/s
• Fillrate:
  • Bitmap/Framebuffer fillrate: 26–28 MPixels/s (24-bit color), 82–85 MPixels/s (15-bit color), 143–150 MPixels/s (8-bit color), 250–264 MPixels/s (4-bit color)
  • Tile fillrate: 280–570 MPixels/s
• Optional MPEG Video CD Card: 704×480 resolution, 30 frames/sec, 16‑bit audio with 44.1 kHz sampling, up to 72 minutes on one CD

SCU DSP

• SCU math coprocessor: Geometry DSP @ 14.31818 MHz, 32‑bit fixed‑point instructions
  • Parallel units: 32/48-bit ALU (arithmetic logic unit), 48/64‑bit Multiplier, 32-bit instruction decoder
• Buses:
  • Internal: 4 parallel buses, 32-bit per bus, 128-bit overall bus width, 3 buses at 14.31818 MHz, 1 bus at 28.63636 MHz
  • External: 32-bit, 28.63636 MHz
• Cache RAM: 2 KB (1 KB data, 1 KB program)
• Instructions: 6 parallel instructions/cycle (one instruction per unit/bus), 85.90908 MIPS (6 MIPS/MHz)
  • Fixed-point operations: 28.63636 MOPS (million operations per second), 2 MOPS/MHz (2 parallel operations/cycle)
• Capabilities: Matrix and vector calculations, 3D point transformations, lighting calculations, fixed-point calculations, faster than SH-2, can use DMA to directly fetch and store vertex data, floating-point operations, geometry transformations, voxel rendering acceleration, fast coordinate transformations, lighting computations, transparency calculations
• Notes: Can only be programmed with assembly language, more difficult to program than SH-2

VDP1

Main article: VDP1 (Saturn).

• VDP1 @ 28.63636 MHz: Handles sprite/texture and polygon drawing, color calculation and shading, geometry
  • Versions: Sega 315‑5883 (Hitachi HD64440) Video Display Processor 1 (VDP1), Sega 315‑5689 VDP1
  • Adjustable video clock rate: 28.63636 MHz or 26.8465875 MHz (NTSC), 28.4375 MHz or 26.8426 MHz (PAL)
  • Parallel data bus structure: 3 parallel data buses (dual framebuffers, texture cache), 48-bit data bus width (16-bit per bus), 171.8184 MB/s bandwidth
  • Parallel data bus cycles: 85.90908 million bus cycles/sec
• Color palette: 32,768 colors (15-bit RGB) to 16,777,216 (24-bit VDP2 CRAM palette, accessible by VDP1)
  • Colors on screen: 32,768 colors (15-bit RGB) to 1,048,576 colors (15-bit RGB, 32 transparency levels using VDP2 palette)
  • Colors per pixel: 32,768 colors (16bpp, 15-bit RGB), 256 colors (8bpp, 8-bit palette)
• Features: Alpha blending, clipping, luminance, shadows, transparency (3 alpha levels, or 32 alpha levels using VDP2 palette), per-pixel transparency
  • Polygon capabilities: Texture mapping, lighting, shading, wire‑frame, flat shading, Gouraud shading, 15-bit color Gouraud shading, 15-bit colored lighting, quad polygons, edge anti‑aliasing, forward texture mapping (form of perspective correction), bilinear approximation (reduces texture warping), medium polygon accuracy (seamless polygons)
• Framebuffer capabilities: Double buffering, dual 256 KB framebuffers, rotation & scaling, VDP1 framebuffer can be rotated as bitmap layer by VDP2
  • Framebuffer resolution: 512×256, 512×512, 1024×256
  • Overscan resolution: 1708×263 (NTSC), 1820×313 (PAL), 852×525 (31KC), 848×562 (HDTV)
• Sprite/Texture capabilities: Rotation & scaling, flipping, distortion, warping, vertical and horizontal line scrolling, virtually unlimited color lookup tables, System 24/32 sprite rendering system
  • Sprite/Texture size: 8×1 to 504×255 texels
  • Colors per sprite/texture in Lo-Res: 16, 64, 128, 256, and 32,768
  • Colors per sprite/texture in Hi-Res: 16, 64, 128, and 256
  • Maximum texels per scanline: 1812 (NTSC), 1820 (PAL)
  • Maximum sprites/textures per scanline: 226 (NTSC), 227 (PAL)
• Texture cache VRAM: 512 KB
  • Sprite/Polygon size: 32 bytes (flat shading), 40 bytes (Gouraud shading), 64–96 bytes (shadows), 72–104 bytes (shadows, Gouraud shading)
  • Texture size: 4 bytes (8×1 texels, 16 colors) to 251.02 KB (504×255 texels, 32,758 colors)
  • Maximum sprites per frame: 16,383 (virtually unlimited), 13,106 (Gouraud shading), 5461–8191 (shadows)
  • Maximum polygons per frame: 16,384 (flat shading), 16,383 (texture mapping), 13,107 (Gouraud shading), 13,106 (texture mapping, Gouraud shading), 8192 (shadows), 8191 (texture mapping, shadows), 7281 (texture mapping, shadows, Gouraud shading)
• Framebuffer fillrate: 28.63636 MPixels/s (16bpp), 35.6465 MPixels/s (8bpp)
  • Gouraud shading: 28 MPixels/s (512×512 polygons),
    16 MPixels/s (10×10 polygons)
  • Shadows/Translucency: 28 MPixels/s (VDP2 palette), 5 MPixels/s (RGB)
• Texture fillrate: 19 MTexels/s (504×255 textures), 14 MTexels/s (10×10 textures), 12 MTexels/s (8×8 textures)
  • Gouraud shading: 19 MTexels/s (504×255 textures), 9 MTexels/s (10×10 textures)
• Polygon rendering performance: Lighting
  • 800,000 polygons/s: Flat shading, 32-pixel polygons
  • 500,000 polygons/s: Flat shading, 50-pixel polygons
  • 200,000 polygons/s: Gouraud shading, 32-pixel polygons
• Texture mapping performance: Lighting
  • 300,000 polygons/s: 32-texel textures
  • 200,000 polygons/s: 70-texel textures
  • 140,000 polygons/s: Gouraud shading, 32-texel textures

VDP2

Main article: VDP2 (Saturn).

• VDP2 @ 57.27272 MHz: Handles background, scroll and 3D rotation planes
  • Versions: Sega 315‑5890 (Yamaha) Video Display Processor 2 (VDP2), Yamaha 315‑5690 VDP2
  • Video clock rate: 26.8426–28.63636 MHz (NTSC), 26.6564–28.4375 MHz (PAL)
  • Memory clock rate: 53.6852–57.27272 MHz (NTSC), 53.3128–56.875 MHz (PAL)
• VDP2 cores: 4 parallel cores (17 units), 28.63636 MHz per core
  • Bus control
  • H/V counter & timing generator
  • Scroll picture block: 8 units (Normal picture coordinate calculation, Rotation picture coordinate calculation, Pattern name control, Window control, Character control, Line picture control, VRAM control, Dot data control)
  • Video process: 7 units (Color offset & shadow, Output data control, Color computing control, Color RAM, Priority control, Color RAM control, Sprite control)
• Features: Transparency (32 levels of transparency, can also be applied to VDP1 polygons/sprites), shadowing, 2 windows for special calculations, matrix calculations, multi-texturing, bump mapping, color gradients
  • 3D infinite planes: Can be manipulated as large polygon objects, with perspective transformation and rotation. Can have curved surface and bumps, and be used for grounds, walls, ceilings, seas, skies, etc.
  • Visual effects: Water, fire, fog, heat haze, misting, reflective water surfaces
• Rotation picture coordinate calculation: Geometry processing unit within Scroll picture block, rotation and transformation of 3D planes, manipulates 3D planes as very large polygons, 24-bit fixed-point operations, 28.63636 MOPS (million operations per second)
• Planes: 7 layers, 2–6 simultaneous layers (1–4 scrolling 2D backgrounds, 1–2 rotating 3D playfields, 1 back screen)
  • 2D scrolling backgrounds: Scrolling, parallax scrolling, single-axis 2D rotation
    • NBG0: 16–16,777,216 colors, tilemap (1024×1024 to 2048×2048) or bitmap (512×256 to 1024×512), column/row/line scrolling, scaling
    • NBG1: 16–32,768 colors, tilemap (1024×1024 to 2048×2048) or bitmap (512×256 to 1024×512), column/row/line scrolling, scaling
    • NBG2/NBG3: 16–256 colors, tilemap (1024×1024 to 2048×2048)
  • 3D rotating playfields: Scrolling, scaling, dual-axis 3D rotation, three-axis 3D rotation, 3D infinite ground planes, perspective correct 3D rotation, can be manipulated as large polygon objects, perspective transformation, can have curved surface and bumps
    • RBG0: 16–16,777,216 colors, tilemap (2048×2048 to 4096×4096) or bitmap (512×256 to 512×512)
    • RBG1: 16–16,777,216 colors, tilemap (2048×2048 to 4096×4096)
  • Back screen: 1 plain background, 1 to 240 colors (1 color/scanline)
• Tile capabilities: 8×8 and 16×16 tile sizes, scroll plane up to 8192×8192 pixels, rotating 3D infinite planes up to 4096×4096 pixels each, tile compression, tile-based texture compression, tiled rendering, virtually unlimited draw distance
• Bitmap capabilities: Bitmap layers can be used as additional framebuffer (with full transparency), displays VDP1 framebuffer as additional bitmap layer, can rotate VDP1 framebuffer
• Color palette: 16,777,216 colors (24-bit), 32,768 colors (15-bit), 65,536 colors (15-bit with transparency)
  • Colors per plane: 16,777,216 colors (3 planes, Lo-Res), 32,768 colors (4 planes), 16–256 colors (6 planes)
• Bitmap fillrate:
  • 2D scrolling planes: 26.8426–229.09088 MPixels/s
    • 16,777,216 colors on screen: 26.8426–28.63636 MPixels/s
    • 32,768 colors per plane: 53.6852–57.27272 MPixels/s
    • 256 colors per plane: 107.3704–114.54544 MPixels/s
    • 16 colors per plane: 214.7408–229.09088 MPixels/s
  • 3D rotation planes: 26.8426–28.63636 MPixels/s
• Tile fillrate: 251.65824–534.77376 MPixels/s
  • 2D scrolling planes: 251.65824–503.31648 MPixels/s
    • Tile fillrate: 3,932,160 tiles/sec, 65,536 tiles per frame
  • 3D rotating playfields: 251.65824–503.31648 MPixels/s
    • Effective polygon fillrate: 1 million texture-mapped polygons/sec (500-texel polygons)

Resolutions

The Saturn supported the following display resolutions:

Progressive

• 320×224 (Lo‑Res)
• 320×240 (Lo‑Res)
• 320×256 (Lo-Res, PAL)
• 352×224 (Lo‑Res)
• 352×240 (Lo‑Res)
• 352×256 (PAL)
• 640×224
• 640×240
• 640×256 (PAL)
• 704×224
• 704×240
• 704×256 (PAL)

Interlaced

• 320×448
• 320×512 (PAL)
• 320×480
• 352×448
• 320×480
• 352×512 (PAL)
• 640×448 (Hi‑Res)
• 640×480 (Hi‑Res)
• 640×512 (Hi‑Res, PAL)
• 704×448 (Hi‑Res)
• 704×480 (Hi‑Res)
• 704×512 (Hi‑Res, PAL)

Sound

Main article: Saturn Custom Sound Processor.

• SCSP @ 22.58 MHz:
  • Audio channels: 32
  • Sound formats: PCM, FM, MIDI, LFO
  • PCM sampling: 16‑bit and 8‑bit audio depth, 44.1 kHz sampling sate (CD quality), up to 32 PCM channels
  • FM synthesis: 1–4 operators per FM channel, up to 32 FM channels (1‑operator) or 8 FM channels (4‑operator)
  • LFO waveforms: 4 waveform types (Sawtooth, rectangular, triangular, white noise), up to 32 LFO channels
• CD‑DA: 1 streaming CD‑DA channel (16‑bit PCM, 44.1 kHz) from CD
• Stereo audio output

Memory

• Total memory: 5–11 MB (5152 KB system, 39,408 bytes cache, 512–5120 KB cartridge, 1 MB card)
  • RAM: 4.549–10.049 MB (4640 KB system, 18,928 bytes cache, 512–5120 KB optional cartridge, 512 KB optional card)
  • ROM: 532–3092 KB (512 KB system, 20 KB cache, 2 MB optional cartridge, 512 KB optional card)
• System RAM: 4.53125 MB (4640 KB)
  • 2 MB Work RAM
    • 1 MB High Work SDRAM
    • 1 MB Low Work FPM DRAM
  • 1.5 MB VRAM
    • 512 KB VDP1 texture cache VRAM
    • 512 KB (2× 256 KB) VDP1 dual framebuffers
    • 512 KB (512 KB) VDP2 background cache VRAM (tiled texture compression up to 17 MB)
  • 512 KB Sound RAM
  • 512 KB CD‑ROM sub‑system buffer data cache
  • 32 KB battery backup SRAM
• System ROM: 512 KB BIOS
• Internal processor cache: 39,408 bytes (38.484375 KB)
  • SH2: 8 KB cache (4 KB per SH2)
  • SH1: 4 KB cache
  • SCU DSP: 2 KB RAM cache (1 KB program, 1 KB data)
  • SMPC: 20,976 bytes (496 bytes 4‑bit RAM, 20 KB 10‑bit ROM)
  • VDP2: 4 KB on‑chip color RAM
• Optional cartridge: 512 KB to 4.5 MB
  • RAM cartridge: 512 KB to 4.5 MB
    • Extended RAM Cartridge: 1 MB or 4 MB Work RAM
    • Saturn Backup Memory: 512 KB battery backup
    • Pro Action Replay: 512 KB battery backup
    • Action Replay Plus: 4.5 MB
      • 4 MB Work RAM
      • 512 KB battery backup
  • Saturn ROM Cartridge: 2 MB (The King of Fighters '95)
• Optional MPEG Video CD Card: 1 MB (512 KB FPM RAM buffer, 512 KB MROM program)

Configuration

System RAM buses, all connected through the SCU:

• System bus
  • SH2 (×2), SCU, SMPC <–> Work RAM, battery backup SRAM
• Video sub‑system buses
  • SCU <–> VDP1, VDP2
  • VDP1 <–> Texture cache VRAM
  • VDP1 <–> Framebuffer 0 VRAM
  • VDP1 <–> Framebuffer 1 VRAM
  • VDP2 <–> Background cache VRAM
• Sound sub‑system bus — SCU, 68EC000, SCSP <‑> Sound RAM
• CD‑ROM sub‑system bus — SCU, SH1 <‑> CD‑ROM cache/buffer RAM

Bandwidth

• System RAM bandwidth: 480 MB/s
  • System bus RAM: 114.54544 MB/s
    • Work RAM: 114.54544 MB/s
    • Battery backup SRAM: 10 MB/s
  • VRAM: 286.3636 MB/s
    • VDP1: 171.81816 MB/s
    • VDP2: 114.54544 MB/s (tiled texture compression up to 534 MB/s)
  • Sound RAM: 40 MB/s
  • CD‑ROM cache/buffer: 40 MB/s
• Internal processor bandwidth:
  • SH2 cache: 229 MB/s
  • SH1 cache: 80 MB/s
  • SCU DSP RAM cache: 286 MB/s
  • SMPC: 7 MB/s
  • 68EC000: 22 MB/s
  • SCSP: 67 MB/s
  • VDP: 286.3636 MB/s
• System ROM bandwidth: 20 MB/s
• Optional cartridge RAM bandwidth: 44 MB/s to 50 MB/s

Storage

• Saturn double-speed CD-ROM drive
  • Storage capacity: 680 MB
  • Data transfer rate: 320 KB/s
  • Access time: Under 360 ms
  • Compatibiity: CD‑ROM, Audio CD, CD+G, CD+EG, CD Single (8cm)
  • Optional: Video CD, Photo CD, Digital Karaoke, E-book
• Cartridge slot: Extended RAM Cartridge, Saturn ROM Cartridge

Input/Output

Main article: List of Sega Saturn accessories.

• Two 16‑bit bidirectional parallel I/O ports
• High-speed serial communications port (Both SH2 SCI channels and SCSP MIDI)
• Cartridge connector
• Internal expansion port for video decoder card
• Composite video/stereo (JP Part No: HSS-0106)
• NTSC/PAL RF (US Part No.: MK-80116, JP Part No.: HSS-0110)
• S-Video compatible (JP Part No.: HSS-0105)
• RGB compatible (JP Part No.: HSS-0109)
• EDTV compatible (optional)

Peripherals

Main article: List of Sega Saturn accessories.

Power source

• AC110 volts; 60 Hz (US)
• AC240 volts; 50 Hz (EU)
• AC100 volts; 60 Hz (JP)
• AC240 volts; 60 Hz (AS)
• AC220 volts; 60 Hz (KR)
• 4 volt lithium battery to power non-volatile RAM and SMPC internal real-time clock
• Power Consumption: 25 W

Dimensions

US/European model:

• Width: 260 mm (10.2 in)
• Length: 230 mm (9.0 in)
• Height: 89 mm (3.2 in)

BIOS

BIOS Revisions

BIOS Version	Machine	Download
1.00	Sega Saturn (Japan)	1.00 (Asian Saturn) (info) ()
1.00a	Sega Saturn (NA & EU)	1.00a (NA & EU Saturn) (info) ()
1.003	Sega Saturn Devkit (Japan)	1.003 (Asian Devkit) (info) ()
1.01	Sega Saturn (Japan), HiSaturn (Japan), V-Saturn (Japan)	1.01 (Asian Saturn) (info) ()
		1.01 (Asian HiSaturn) (info) ()
		1.01 (Asian V-Saturn) (info) ()
1.01a	Sega Saturn (NA & EU)	1.01a (NA & EU Saturn) (info) ()
1.02	HiSaturn (Japan)	1.02 (JP HiSaturn) (info) ()
1.03	HiSaturn Navi (Japan)	1.03 (JP HiSaturn Navi) (info) ()

Errata

See VDP1 Errata

VDP1 transparency rendering quirk causes strips of pixels to be rewritten to framebuffer for 2-point (scaled) and 4-point (quadrangle) "sprites", applying the transparency effect multiple times. Rarely seen in commercial games (e.g. Robotica explosions), later titles implemented software transparency to correctly render transparent polygons (e.g. Smoke, shadows and a lot of particles in Loaded).

The VDP1 supports per-pixel transparency between different polygons/sprites in the VDP1 framebuffer, or between VDP1 and VDP2 layers, but not both at the same time, with the VDP2's transparency overriding the VDP1's transparency. There are several ways to overcome this issue. The most common method used by Saturn games is to fake transparency with dithering, using a mesh that gets blended by a television's Composite or S-Video cable. Another method is using a VDP2 bitmap layer as an additional transparent framebuffer, copying transparent assets from the VDP1 framebuffer to a VDP2 bitmap framebuffer layer (e.g. the transparent polygons in Burning Rangers). Another method is software transparency, programming the CPU with software code.

Technical comparison

Main article: Sega Saturn/Hardware comparison.

History

Main article: History of the Sega Saturn.

Emulation

The Saturn is notoriously hard to emulate due to its complex architecture (dual processors, etc.), but four notable emulators do exist:

• SSF is a highly compatible emulator, which is in continual development by a single developer.
• GiriGiri was initially based on an abandoned emulator by Sega themselves, and was considered the best until development ceased and SSF overtook it.
• Yabause is an open-source effort to create a Saturn emulator.
• Mednafen Sega Saturn is still in an experimental stage, but already highly compatible and can play games that don't work properly with SSF or Yabause.

Software that plays files in the Saturn Sound Format, which stores audio ripped from games, does so through emulation of the audio-related code only.

Games

Main article: Sega Saturn games.

Magazine articles

Main article: Sega Saturn/Magazine articles.

Promotional material

Print advertisements

|

Print advert in Sega Visions (US) #24: "May 1995" (1995-xx-xx)

|

Print advert in Game Players (US) #0811: "Vol. 8 No. 11 November 1995" (1995-1x-xx)

|

Print advert in Next Generation (US) #11: "November 1995" (1995-10-24)
also published in:

• Electronic Gaming Monthly (US) #77: "December 1995" (1995-xx-xx)

|

Print advert in Next Generation (US) #18: "June 1996" (1996-05-21)
also published in:

• GamePro (US) #93: "June 1996" (1996-xx-xx)

|

Print advert in Player One (FR) #57: "Octobre 1995" (1995-xx-xx)
also published in:

• CD Consoles (FR) #11: "Novembre 1995" (1995-xx-xx)

|

Print advert in CD Consoles (FR) #12: "Décembre 1995" (1995-xx-xx)

|

Print advert in Hobby Consolas (ES) #46: "Julio 1995" (1995-xx-xx)

|

Print advert in Hyper (AU) #21: "August 1995" (1995-xx-xx)
also published in:

• Hyper (AU) #20: "July 1995" (1995-xx-xx)

|

Print advert in Ação Games (BR) #91: "Setembro 1995" (1995-09-16)
also published in:

• SuperGamePower (BR) #19: "Outubro 1995" (1995-xx-xx)
• Video Game (BR) #54: "Outubro 1995" (1995-xx-xx)

• 

  KR print advert

• SPC Saturn Print Ad 2 KR.jpg

  KR print advert

• Saturn Price Drop Print Ad KR.jpg

  KR print advert

• KDS Saturn Print Ad KR 1.jpg

  KR print advert

• KDS Saturn Print Ad KR 2.jpg

  KR print advert

Pamphlets

• 

  EU (1996)

• 

  EU (1997-01)

• 

  EU (1997)

• 

  AU

Television advertisements

• JP (launch)

• US (1)

• US (2)

• US (Who?)

• US (Who? 15 second variant)

• UK (launch; long)

• UK (launch; short)

Artwork

• 

  Japanese logo

• 

  North American/European/Australian/Brazilian logo

• 

  Korean logo

• 

  Korean logo, used on magazine advertisements

Patents

• 

  USD362869

• 

  USD362870

External links

• Dave's Sega Saturn Page - Famous fansite that was extremely popular during the Saturn's heyday (no longer updated).

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