CruSega wrote:
Right. Weren't they developed with the help of Lockheed, who are contractors for the US military? Model 2 and Model 3 were state of the art hardware while Saturn was comprised of off-the-shelf components.
That is correct, The Model 2 was developed by Martin Marietta Corp, who were later taken over by Lockheed Martin. MMC developed a high performance chipset for Model 2 that allowed for 300,000 texture mapped, shaded, lit polygons per sec, and the system had a total throughput of about 900,000 vectors per second.
Here are the specs for the Model 2 arcade board:
Main CPU : Intel i960-KB @ 25 MHz 32bits RISC
Graphics Co-Processor : Fujitsu TGP MB86234 FPU 32bits 16M flops
Co-Processor Abilities : Floating decimal point operation function, Axis rotation operation function, 3D matrix operation function
Sound CPU : 16bits 68000 @ 10Mhz
Sound chip : 2 x Custom 28 channel PCM chips, 1 for Music and 1 for Effects (Can access up to 8meg sample rom *per chip*)
Sound Timing Chip : YM3834 @ 8MHz (only used for its timers)
Audio RAM : 540 Kilobytes (4 megabits)
Video resolution : 496x384 in 65536 colors
Geometry : 300,000 polygons/s. 900,000 vectors/s
Rendering : 1,200,000 pixels/s
Video : Shading Flat Shading, Perspective Texture, Micro Texture, Multi Window, Diffuse Reflection, Specula Reflection
As for the Saturn, it was an Sega in house design utilizing 8 separate processors and used a combination of 'off the shelf' components, with 2 Sega designed Video Display Processors, VDP1 was used for drawing the polygons and for texture mapping too, it could also do the more traditional sprites with full sprite scaling and rotation. The VDP2 was added late on in the development of the Saturn and was responsible for all the background graphics The processors included in the Saturn are as follows: 2x SH2, VDP1, SCU, VDP2, 68EC000, FH1 and an SH1.
This complicated architecture created 2 big issues for Sega, firstly it made the Saturn an expensive machine to manufacture and therefore would of meant that they were losing a lot of money the entire time they were selling it, since there were all these chips it meant that the mainboard was large and therefore expensive. The other issue was that it made the Saturn a very difficult to program machine and since Sega never bothered to offer decent programming libraries, the lack of good tools and documentation made the situation even worse.
Here are the specs for the Sega Saturn:
Processors: 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)
Motorola 68EC000 sound controller (running at 11.3 MHz / 1.5 MIPS)
Yamaha FH1 DSP sound processor, "Saturn Custom Sound Processor" (SCSP), running at 22.6 MHz
SH-1 32-bit RISC microcontroller (for the CD-ROM and CD security checks; uses preprogrammed embedded ROM, not programmable by software)
Hitachi 4-bit MCU, "System Manager & Peripheral Control" (SMPC)
[edit] Memory1 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
As you can see, the two systems are very different and in no way similar in design, in fact the only similarity is that they both use quadralaterals as their 3D primitives, rather than triangles. Other than that they use different CPUs and different graphic chips, the Saturn can do 2D sprite based games, but the Model 2 is 3D polygon only.
The only arcade board that shares technology with the Saturn is the ST-V (Sega Titan Video system), this was an arcade version of the Saturn that used a ROM board for game storage, instead of the CD-Rom.