Having not purchased a new gaming console for quite a while, I was pretty excited about the debut of the Sega Saturn. It seemed like it could be the next big thing. Dual 32 bit processors sounded good, right?
So I went out and dropped $400 on this fucking clunker. The Genesis was popular and I should have known that Sega was racing downhill ever since, but this somehow eluded me and I became a Saturn owner.
Virtua Fighter was pretty cool... alas it quickly met its demise as the Playstation emerged as the dominant console.
Sega Saturn - Technical Specifications
The Sega Saturn is a 32-bit video game console that was first released on November 22, 1994 in Japan, May 11, 1995 in North America, and July 8, 1995 in Europe. The system was discontinued in North America, Europe, and Australia in 1998, and in 2000 in Japan. While it was popular in Japan, the Saturn failed to gain a similar market share in North America and Europe against Sony's PlayStation and the Nintendo 64, its main competitors.
According to a July 2007 GamePro article, the Saturn sold 9.5 million units worldwide. In 2009, video game website IGN chose the Saturn to be their 18th best video game console of all time, out of 25.
Sega's 27-member Away Team, comprising employees from hardware engineering, product development and marketing, worked for two years beginning in February 1993 to design the Sega Saturn's hardware. Since the project was top secret, Hayao Nakayama dubbed the project "Aurora". The Saturn was a powerful machine for the time, but its design, with two CPUs and six other processors, made harnessing this power extremely difficult. Also, many of the ancillary chips in the system were "off the shelf" components, increasing the complexity of the system because the components were not specifically designed to work together.
Rumors suggest that the original design called for a single central processor, but upon hearing of the PlayStation's capabilities, a second processor was added late in development to increase potential performance[who?]. At the roll out of 3DO in 1993, Sega of America president Tom Kalinske boasted that "we have a more powerful machine waiting in the wings, but the time's not ready yet." However, one major design change was forced on Sega, and the culprit was the Sony PlayStation.
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. At least during early Saturn development, programming in assembly could offer a two to fivefold speed increase over the C language. To save development costs and time, some programmers would utilize only one CPU, such as with Alien Trilogy.
The Saturn's dual-CPU architecture was the source of some difficulty for developers. The biggest disadvantage was that both processors shared the same bus and had problems accessing the main system RAM at the same time. The 4 KB of cache memory in each CPU was critical to maintaining performance. In general, very careful division of processing, in addition to the already-challenging task of parallelizing the code, was required to get the most out of the Saturn. One example of how the Saturn was utilized was with Virtua Fighter's use of one CPU for each character.
Compared to the PlayStation, the Saturn's hardware was difficult to work with because of its more complex graphics hardware and lesser overall performance, as noted by Lobotomy Software programmer Ezra Dreisbach. In order to port Duke Nukem 3D and PowerSlave/Exhumed to the Saturn, Lobotomy Software had to almost entirely rewrite the Build engine to get adequate performance from the Saturn. Also, during testing of an unreleased Quake port for the PlayStation, the Saturn's performance was found to be notably inferior for the game.
However, later programming techniques employed by Sega's AM2 saw an improvement in performance. Video exists of a canceled version of Shenmue - later released on the Sega Dreamcast - running on a stock Sega Saturn. The video was included in the Dreamcast title Shenmue II.
Unlike the PlayStation and Nintendo 64 which used triangles as its basic geometric primitive, the Saturn rendered quadrilaterals. This proved to be a hindrance because most of the industry's standard design tools were based on triangles. One of the challenges brought forth by quadrilateral-based rendering was problems with making some shapes, notably triangular objects. This can be seen in the Saturn version of Tomb Raider, in which triangular rocks are not rendered as well as other systems' versions of the game. The hardware also lacked light sourcing and hardware video decompression support, the latter being a major disadvantage during a time when full-motion video was quite popular.
If used correctly, the quadrilateral rendering of the Saturn had advantages. It could potentially reduce the texture distortion common in PlayStation titles, as demonstrated by several cross-platform titles such as Wipeout and Destruction Derby. The quadrilateral-focused hardware and a 50% greater amount of video memory also gave the Saturn an advantage for 2D game engines and attracted many developers of RPGs, arcade games and traditional 2D fighting games. With creative programming, later games like Burning Rangers were able to achieve true transparency effects on hardware that used simple polygon stipples as a replacement for transparency effects in the past.
The cartridge slot gave the potential for adding extra RAM or storage devices for saving games to the system. Two ROM cartridges were released with Sega Saturn games: one with King of Fighters '95 and the other with Ultraman: Hikari no Kyojin Densetsu. The ROM cartridges contained part of the game data because not enough system RAM was available. Two different RAM cartridges were released for the system; a 1 MB RAM cart by SNK for King of Fighters '96 and a 4 MB RAM cart by Capcom for X-Men vs. Street Fighter and Marvel Super Heroes vs. Street Fighter. A RAM expansion cartridge was also required for the games Groove on Fight & Final Fight Revenge. Both companies were known for their sprite-based 2D competitive fighting games and many of their subsequent games utilized their respective cartridges. (such as "Vampire Saviour" & "Cotton 2").
Two Hitachi SuperH-2 7604 32-bit RISC processors at 28.63 MHz (25 MIPS) - each has 4 kB on-chip cache (4-way associative), of which 2 kB can alternatively be used as directly addressable Scratchpad RAM
Custom VDP 1 32-bit video display processor (running at 28.63 MHz on NTSC and PAL Systems) for sprites/polygons
Custom VDP 2 32-bit video display processor (running at 28.63 MHz on NTSC and PAL Systems) for backgrounds/video out
Custom System Control Unit (SCU) with DSP for geometry processing and DMA controller (running at 14.3 MHz)
1 MB SDRAM as work RAM for both SH-2 CPUs (faster)
1 MB DRAM as work RAM for both SH-2 CPUs (slower)
512K VDP1 SDRAM for 3D graphics (Texture data for polygon/sprites and drawing command lists)
2x 256K VDP1 SDRAM for 3D graphics (Two framebuffers for double-buffered polygon/sprite rendering)
512K VDP2 SDRAM for 2D graphics (Texture data for the background layers and display lists)
4 KB VDP2 SRAM for color palette data and rotation coefficient data (local, on-chip SRAM)
512 KB DRAM for sound. (Multiplexed as sound CPU work RAM, SCSP DSP RAM, and SCSP wavetable RAM)
512 KB DRAM as work RAM for the CD-ROM subsystem's SH-1 CPU
32 KB SRAM with battery back-up for data retention.
512 KB Mask ROM for the SH-2 BIOS
The Saturn Custom Sound Processor (SCSP) is manufactured by Yamaha and consists of several components.
The SCSP is a multi-function game sound generator LSI that consists of a PCM sound generator and DAC (Digital to Analog Converter). The SCSP creates and processes sound mixes. It contains a 32-slot sound generator and sound effect DSP, a 16-channel digital mixer and timer, and an interrupt controller. The Saturn's audio RAM is connected directly to the SCSP, and is used to store the sound programs (i.e. Cybersound) or raw waveform samples. The SCSP can support up to 32 channels for PCM playback, or eight channels for FM synthesis modulation. Maximum sample rate for PCM samples is 44.1 kHz (CD quality). The SCSP is MIDI compliant, and can be hooked up to external equipment (such as keyboards).
The 128 step DSP is capable of generating special effects such as reverberation and different room acoustics.
The entire SCSP is controlled by a single Motorola 68EC000 16-bit CPU running at 11.3 MHz. The MC68EC000 is essentially the same as (and compatible with) the M68000 used in the Mega Drive and several other consoles, but without the eight-bit MC6800 interface. The SCSP can be directly accessed by the MC68EC000 and both SH-2s.
The SCSP is limited by the small amount of RAM made available to it, and lack of hardware sample compression.
22.6 MHz Yamaha FH1 digital signal processor
Any of 32 slots can be linked together for multiple operators per FM sound channel
Usually four operators used per slot for eight FM channels total
44.1 kHz sampling rate
The SCSP was also used in some arcade video game boards, such as the Sega Model 2 and 3.
The Sega Saturn is equipped with dual custom VDP chips for graphics processing. The VDP1 chip is primarily responsible for sprite generation. Polygon generation is accomplished through manipulation of the sprite engine. Texture mapping and Gouraud shading is also handled by the VDP1.
The VDP1 renders primitives to two 256 kB frame buffers that can be configured as 512x512x8 or 512x256x16 (Virtua Fighter 2 was the first game to use high resolution, at 60 frame/s on Consoles). Having two frame buffers allows double buffering of the display and provides more time for rendering. The active framebuffer is read out to the display by the VDP2, which can apply data from a coefficient table to modify the scanning process, for effects like rotation, scaling, and general distortion of the entire frame buffer as a single entity.
The SCU (system bus control unit) provides DMA across a dedicated bus commonly labeled as the "B-bus" that the VDP2 and VDP1 are connected to, allowing transfer of data from them to and from main memory. Keep note that transferring data from and to the same bus is prohibited by all 3 SCU DMA levels.
Rendering engine for command tables: textured and non-textured polygons, untextured "polygons," "polylines," and lines along with command tables that controls the frame buffer.
"Sprites" are textured polygons with specific rendering modes:
Shadow (underlying frame buffer pixels rewritten with 1/2 brightness, primitive not drawn)
Half luminosity (primitive rendered with 1/2 brightness)
Half transparency (primitive and underlying framebuffer pixels averaged together)
Gouraud shading for RGB-format textures only
Dual 256KB frame buffers
Programmable frame buffer depth of 8 or 16 bits per pixel
Automatic erase feature to clear framebuffer with single color
Some commonly quoted specifications are highly dependent on the rendering modes for the polygons and other factors that burden the system load:
200,000 texture-mapped polygons per second
500,000 flat-shaded polygons per second
60 frames of animation per second
In order to better understand the differences between the PlayStation GPU and Saturn VDP1 rendering capabilities, here are some varying factors:
The GPU has a unified 1 MB block of memory for the texture data and frame buffers. This allows for complex effects where the framebuffer is in turn applied as a texture again.
The GPU has a 2 kB texture cache.
The framebuffer portion of the GPU RAM must be manually erased.
Commands are sent to the GPU via DMA, buffered in a FIFO, and executed in the order of being sent.
VDP1 memory is split: 512 kB for texture data / command lists, 256 kB for one frame buffer and 256 kB for another. Because of the split, it is not possible to use the frame buffer as a texture.
The VDP1 has no texture cache, but since texture memory and the frame buffer have separate buses and can be accessed simultaneously, there isn't a speed penalty.
The two frame buffers have a high-speed auto-erase feature.
Commands are stored in a linked list in RAM, multiple lists can be stored, the list can be processed by the VDP1 without wasting a DMA channel.
VDP2 1st version
The VDP 2 serves as the Sega Saturn's background processor. Certain special effects such as texture transparency and playfield rotation and scrolling (up to five fields at any given time) are handled here. Both the VDP2 and VDP1 32-bit video display processor have direct access to the both SH2s, as well as direct memory access (DMA) to both the main and video RAM.
Four simultaneous scrolling backgrounds
Uses 8x8 or 16x16 tiles or bitmap display per background
Programmable memory access controller for VDP2 VRAM
Two simultaneous rotating playfields
VDP2 can rotate VDP1 framebuffer position while scanning out to display for rotation effects
Color RAM supports 15-bit (32768 colors) and 24-bit (16.7 million colors) display modes
Programmable priority at the per-background / per-tile / per-pixel levels
Background color tinting/fading, and transparency effects
Background blur effect (gradation) to simulate distance
Programmable display resolution:
Horizontal sizes of 320, 352, 640, 704 pixels
Vertical sizes of 224, 240, 256 scanlines, non-interlaced
Vertical sizes of 448, 480, 512 scanlines, interlaced (only PAL consoles support 256 and 512 scanline displays)
Hi-Vision (EDTV) and 31 kHz (VGA) display support:
31 kHz: 320×480 or 640×480, non-interlaced (progressive scan)
Hi-Vision: 352×480 or 704×480, non-interlaced (progressive scan)
The Sega Saturn video game console features a double speed CD-ROM drive manufactured by JVC-Victor (some models may have been manufactured by Hitachi or Sanyo). The drive has a transfer rate of 320 KB/s, and a 512 KB data cache. Drive related functions are controlled via a single Hitachi SH1 32-bit RISC processor operating at 20 MHz.
Audio CD compatible
CD single (8 cm CD) compatible
Video CD (required optional MPEG add-on), Photo CD, Electronic Books, digital karaoke (optional)
Two 7-bit bidirectional parallel I/O ports (controller ports)
High-speed serial communications port (Both SH2 SCI channels and SCSP MIDI, also used for the Serial port)v
Internal expansion port for optional MPEG adapter card (different models available from Sega, JVC, and Hitachi)
Composite video/audio (standard)
NTSC/PAL RF (optional RF adapter required)
S-Video compatible (optional cable required)
RGB compatible (optional cable required)
EDTV/Hi-Vision compatible (custom cable required, not commonly available)
While the Saturn graphics hardware is capable of VGA (progressive/non-interlaced) video, no existing retail software ever used this mode and the system cannot force any such software to run in this mode. Moreover, neither Sega nor third-party manufacturers produced or sold the cables required to support such high-resolution modes on any type of display.
AC120 volts; 60 Hz (US)
3 volt lithium battery to power non-volatile RAM and SMPC internal real-time clock