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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, resulting in a lack of good options. However, things are looking up for open-source emulators like Mednafen, and to a lesser extent, Yabause.

• 1Emulators

Emulators[edit]

Many of the Saturn’s best games have still not been ported to other consoles. A new generation of retro gamers are just now discovering what the Saturn has to offer. While emulation of the console has improved a lot over the last decade, fast and accurate emulation can still be challenging. Download MAME and the GUI, unzip both files to the same directory, and run the 'Play GUI' executable. It's nothing but a (long) list from which to select games, though it supports find-as-you-type.

Comparisons[edit]

Mednafen

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 very demanding, having recommendations to use a quad-core Intel Haswell CPU with a base frequency of >= 3.3GHz and a turbo frequency of >= 3.7GHz (e.g. Xeon E3-1226 v3 or i5-4590).^[1]. By default, only x86-64 builds have Saturn support, but unofficial x86-32 builds and libretro frontends like RetroArch can surpass this limitation.

MedSat

An unofficial frontend, built by Saturn romhacker paul_meta, to simplify the process of loading Saturn games.

SSF

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 in mid-end (and maybe low-end) computers.

Yabause

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 Kronos which is recommended for PCs and YabaSanshiro which is recommended for Android.

YabaSanshiro (formerly uoYabause)

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. UoYabause Compatibility List and official compatibility page.

Kronos

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). Compatibility list of Kronos.

MAME

Has a saturn driver with compatibility on par with Yabause. The driver is marked overall as not working but graphics and sound are OK. It has goodcompatibility with at least around 50 of the ~70 ST-V arcade games, though performance quality may vary.^[2] But versions 0.158^[3] (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)

Nova

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.)

BizHawk

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 progresses in the Kronos fork.)

Emulator development[edit]

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 Virtua Fighter development.^[4]

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.^[4] 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.^[5] 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.^[5] 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.^[4] Sega responded to these criticisms by writing new graphics libraries which were claimed to help make development easier.^[6] These libraries were presented as a new operating system by Sega of Japan.^[6]

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. In order 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.^[5]

Resources[edit]

• 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)

Kronos

References[edit]

1. ↑https://mednafen.github.io/documentation/ss.html
2. ↑Sega ST-V Arcade Games A to Z - M.A.M.E.. Youtube (2017-02-10)
3. ↑Touryuu Densetsu Elan Doree - New Improvements on ST-V Hardware - MAME 0.158. Youtube (2015-02-03)
4. ↑ ^4.04.14.2Next Generation (magazine) issue 2, 1995
5. ↑ ^5.05.15.2Interview: Ezra Dreisbach. Curmudgeon Gamer (July 9, 2002)
6. ↑ ^6.06.1So many 32-Bit Systems To Choose From Next Generation (magazine) issue 12, 1995

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Emulate Saturn Games Online