Sega Saturn emulators
|Type||Home video game console|
|Predecessor||Genesis / Mega Drive|
The Sega Saturn is a 32-bit, fifth-generation console released by Sega in Japan on November 22, 1994 and in the US on May 11, 1995. It was retailed for $399.99. It had 2 Hitachi SH-2 CPUs at 28.6 MHz and it had the VDP1 GPU & VDP2 GPU. The arcade board, ST-V (Sega Titan Video), uses the same hardware except for sound, VRAM, and game storage (where it is stored on ROM cartridges instead of CD-ROM discs).
The Sega Saturn has historically been one of the harder consoles to emulate due to its infamously difficult architecture consisting of 8 processors overall and use of quadrilaterals rather than triangles as polygons, resulting in a lack of good options. However, things are looking up for open-source emulators like Mednafen, and to a lesser extent, Yabause.
- Version 1.31.0 added experimental support for ST-V games that don't require decryption chips or special hardware. Refer to the ST-V section of the official documentation for more details and a list of explicitly supported games.
- Exclusive to libretro core.
- Yaba Sanshiro libretro core (yabasanshiro_libretro) is outdated, known for having many issues, and unmaintained. Use standalone version OR "yabause_libretro" or "mednafen_saturn_libretro" cores for RetroArch Saturn emulation.
- Due to recent virus detections in the latest versions, it is risky for some computers to use. This emulator remains somewhat recommended especially for older hardware, though it may be avoided for these reasons.
- Libretro core is still active.
- One of the best emulators for ST-V emulation but still "Imperfect".
- Mednafen (compatibility, JAP compatibility, PAL compatibility, USA compatibility , st-v compatibility)
- An open-source, multi-system emulator with an original Saturn core. It's currently the most accurate but runs from the command-line (obviously it'll have video output though) unless using an external frontend like Mednaffe or a libretro frontend like RetroArch. Its goal for accuracy means it only supports the BIOS of one console revision per region, and is also more demanding than any other Saturn emulator (other than MAME). By default, only x86-64 builds have Saturn support, but unofficial x86-32 builds and libretro frontends like RetroArch can surpass this limitation.
- SSF (USA compatibility, JPN compatibility, PAL compatibility)
- Used to be the emulator of choice for compatible Saturn emulation. However, it is closed-source and only for Windows and Android. Pretty good performance with low-end computers.
- City Connection uses SSF as part of Zebra Engine, the engine behind their Saturn Tribute releases, currently for Switch, PS4, Xbox One and PC. Some games are altered with English translations (Assault Suit Leynos 2) or with censorship from CERO (Idol Janshi Suchie-Pai series).
- Yabause (compatibility)
- Used to be the first and only option for multi-platform Saturn emulation. It's far less developed than SSF and Mednafen and still has many compatibility issues. Development seems to have stopped, active forks are Libretro core, Kronos and Yaba Sanshiro 2.
- Yaba Sanshiro 2 (formerly uoYabause) (compatibility)
- A Multi-platform fork by DevMiyax using OpenGL ES 3.X (Android), and Open GL 3.X (Windows). Unlike other forks, it uses the GPU to emulate the VDP1, VDP2, and has a modified SH2 Dynamic Recompiler.
- Kronos (compatibility)
- A fork of UoYabause 0.5.2 created by François (French dev. AKA 'FCare'.). Has his own written SH2 Interpreter, and now supports the ST-V arcade in version 1.30, and Higher (All ST-V games are launchable on Linux; most games are still problematic on Windows). 2115 games have been tested : 1884 are playable (89.08 %), 209 are not, 19 are almost playable.
- MAME (compatibility, st-v compatibility)
- Has a
saturndriver with compatibility on par with Yabause. The driver is marked overall as not working but graphics and sound are OK. It has good compatibility with at least around 50 of the ~70 ST-V arcade games, though performance quality may vary. But versions 0.158. (Jan 2015) to much later have made good advances in performance. Early known work on ST-V hardware emulation was done in various builds of 0.125, 0.133, 0.138, 0.142 & 0.143 (See prior builds) between 2008-2011. Even bug fixes and more graphical improvements were included in the years 2017-2018 (i.e. 0.191, 0.197 & 0.198).
- - Sega Saturn JP compatibility list (Created by MAME dev Angelo 'Kale' Salese)
- An up-and-coming emulator focused on being fast, compatible, and user-friendly. Like SSF, it is closed-source and Windows only. From v0.2.1 onwards, it can now emulate the Sega Titan Video (ST-V) arcade hardware (eg. Guardian Force on ST-V in v0.2.2.). Refer to compatibility list (Not updated every version. Note that the 'Playable' category may only mean the games being in-game but with visual errors).
- An open-source, multi-system emulator designed for tool-assisted speedruns. Its Saturn core is based on Mednafen.
Comparisons of several Saturn emulators:
- A Deep Dive into the Sega Saturn and Saturn Emulation (By Dolphin tester, JMC47, AKA Justin M. Chadwick. 13 OCTOBER 2017. Tested emulators: Yabause & uoYabause, SSF (unofficial site), and Mednafen. Already outdated the next year by progress in the Kronos fork).
Hardware Features and Accessories
|Name||Mednafen||Kronos||Yaba Sanshiro 2||Saturnin|
|Sega Net Link/XBⱯND modem||✗[N2 1]||✗||✓*||✗|
|3D Control Pad||✓*||TBD||TBD||✗*|
|Dual Mission Stick||✓*||TBD||TBD||✗*|
|Real Arcade Light Gun||TBD*||TBD||TBD||✗*|
|6Player & SBom Multitap||✓*||TBD||TBD||✗*|
Sometimes called "XBAND" and is a modem for Sega Saturn. Possibly can be emulated by YabaSanshiro.
Video CD Card
Also called the Movie Card in Japan - allows Saturn to play Video CDs (VCDs) and hardware playback of MPEG-1 (version 1) video in certain games, leading to higher quality FMV for use in cutscenes (and occasionally, gameplay) (similar to the Philips CD-i's Digital Video Cartridge). It is not known what emulators support this accessory.
- This section was copied from Wikipedia in 2014. For an up-to-date explanation, see Sega Saturn § Technical specifications
The complexity of the system has made the creation of a proper emulator for it rather difficult.
One very fast central processor would be preferable. I don't think all programmers have the ability to program two CPUs — most can only get about one-and-a-half times the speed you can get from one SH-2. I think that only 1 in 100 programmers are good enough to get this kind of speed [nearly double] out of the Saturn. "Yu Suzuki reflecting upon Saturn's Virtua Fighter development.
The Saturn had technically impressive hardware at the time of its release, but its complex design, with two CPUs and six other processors, made harnessing this power difficult for developers accustomed to conventional programming. The biggest disadvantage was that both CPUs shared the same bus and were unable to access system memory at the same time. Making full use of the 4 kB of cache memory in each CPU was critical to maintaining performance. One example of how the Saturn was utilized was with Virtua Fighter's use of one CPU for each character. Many of the Saturn's developers, such as Lobotomy Software programmer Ezra Dreisbach, found it difficult to develop for compared to the PlayStation because of its more complex graphics hardware. In order to port Duke Nukem 3D and PowerSlave to the Saturn, Lobotomy Software had to almost entirely rewrite the Build engine to take advantage of the Saturn's unconventional hardware. Third-party development was initially hindered by the lack of useful software libraries and development tools, requiring developers to write in assembly language to achieve good performance. During early Saturn development, programming in assembly could offer a two to fivefold speed increase over C language. Sega responded to these criticisms by writing new graphics libraries which were claimed to help make development easier. These libraries were presented as a new operating system by Sega of Japan.
Unlike the PlayStation and Nintendo 64 which used triangles as their basic geometric primitive, the Saturn rendered quadrilaterals with forward texture mapping. This proved to be a hindrance because most of the industry's standard design tools were based on triangles, with independent texture UV coordinates specified per vertex. One of the challenges brought forth by quadrilateral-based rendering was problems with textured surfaces containing triangles. To make a triangular-shaped object, rendering had a fourth side with a length of zero. This technique proved problematic as it caused texture distortion and required careful reworking to achieve the desired appearance—Sega provided tools for remapping textures from UV space into rectangular tiles. These complications can be seen in the Saturn version of Tomb Raider.
For more information about Sega Saturn hardware and reverse engineering;
- Rodrigo Copetti: Sega Saturn Architecture analysis
- MVG: How the SEGA Saturn CD Security was defeated
- PSDevWiki: PS4's Sega Saturn Emulation
- LGR: Oddware - Diamond Edge 3D (nVidia NV1+Sega Saturn Ports)
- Graphics comparison table (for Saturn as opposed to PS1, N64, Sega Model 2 arcade hardware and 1995-era PC)
- More leaked, official documentation (Only that this time there are some that include for Sega Genesis, its CD add-on, and documentation on how the Sega Saturn CD Communication Interface works, and how its Boot ROM works Source)
- Sega ST-V Arcade Games A to Z - M.A.M.E.. Youtube (2017-02-10)
- Touryuu Densetsu Elan Doree - New Improvements on ST-V Hardware - MAME 0.158. Youtube (2015-02-03)
- Next Generation (magazine) issue 2, 1995
- Interview: Ezra Dreisbach. Curmudgeon Gamer (July 9, 2002)
- So many 32-Bit Systems To Choose From Next Generation (magazine) issue 12, 1995