Sega Virtua Processor
Encyclopedia
The Sega Virtua Processor (short: SVP) is a DSP
introduced by Sega
in 1994 to expand the Mega Drive's (Sega Genesis in North America) 3D capabilities.
The SVP was Sega's answer to Nintendo
's Super FX
processor used in some of their SFC/SNES
cartridges.
SSP1601 16-bit Fixed Point DSP with Sega brand
ing. For a long time it was assumed to be a SH-x DSP
in the homebrew
scene. The assumption was based on the fact that Sega has used SH-1 and SH-2 processors for their 32X
and Saturn
consoles.
The only usage of the SVP was in the Mega Drive version of Virtua Racing
. Its main task was to calculate the polygonal graphics
of the game. The main purpose of the SVP is to render polygons as 8x8 tiles, which the game program transfers to VRAM from the 128K RAM area using DMA
. The SVP runs at 23 MHz and can calculate 300 to 500 polygons/frame at 15 frames per second (up to 6,500 polygons per second) with a maximum of 16 colors. It also has its own small heat sink because it gets warm during operation.
70 in the UK, and $100 in the U.S.
), which can be seen as a major reason why the SVP was only used in Virtua Racing. Sega of America started to develop the 32X
expansion console around that time.
Due to a clash between memory addresses used by the 32X and the SVP, Virtua Racing is the only Mega Drive game which doesn't run with an attached 32X. A 32X version of the game called Virtua Racing Deluxe was released later in 1994, featuring more polygons per track and car, three cars and two more tracks. It has been theorized by many that an SVP adapter (similar to the 32X) was in development prior to the 32X creation.
An emulator for the Wii
console called Genesis Plus GX is able to emulate the SVP.
Also, an emulator called Regen, emulates the SVP.
As of version 3.6, the Kega Fusion Genesis/32x/CD emulator supports SVP emulation.
Digital signal processor
A digital signal processor is a specialized microprocessor with an architecture optimized for the fast operational needs of digital signal processing.-Typical characteristics:...
introduced by Sega
Sega
, usually styled as SEGA, is a multinational video game software developer and an arcade software and hardware development company headquartered in Ōta, Tokyo, Japan, with various offices around the world...
in 1994 to expand the Mega Drive's (Sega Genesis in North America) 3D capabilities.
The SVP was Sega's answer to Nintendo
Nintendo
is a multinational corporation located in Kyoto, Japan. Founded on September 23, 1889 by Fusajiro Yamauchi, it produced handmade hanafuda cards. By 1963, the company had tried several small niche businesses, such as a cab company and a love hotel....
's Super FX
Super FX
The Super FX is a coprocessor chip used in select Super Nintendo Entertainment System video game cartridges. This custom-made RISC processor was typically programmed to act like a graphics accelerator chip that would draw polygons to a frame buffer in the RAM that sat adjacent to it...
processor used in some of their SFC/SNES
Super Nintendo Entertainment System
The Super Nintendo Entertainment System is a 16-bit video game console that was released by Nintendo in North America, Europe, Australasia , and South America between 1990 and 1993. In Japan and Southeast Asia, the system is called the , or SFC for short...
cartridges.
Technical details
The SVP is thought to be a SamsungSamsung
The Samsung Group is a South Korean multinational conglomerate corporation headquartered in Samsung Town, Seoul, South Korea...
SSP1601 16-bit Fixed Point DSP with Sega brand
Brand
The American Marketing Association defines a brand as a "Name, term, design, symbol, or any other feature that identifies one seller's good or service as distinct from those of other sellers."...
ing. For a long time it was assumed to be a SH-x DSP
SuperH
SuperH is a 32-bit reduced instruction set computer instruction set architecture developed by Hitachi. It is implemented by microcontrollers and microprocessors for embedded systems....
in the homebrew
Homebrew (video games)
Homebrew is a term frequently applied to video games or other software produced by consumers to target proprietary hardware platforms not typically user-programmable or that use proprietary storage methods...
scene. The assumption was based on the fact that Sega has used SH-1 and SH-2 processors for their 32X
Sega 32X
The Sega 32X, codenamed Project Mars, is an add-on for the Mega Drive/Genesis video game console by Sega. Its aim was to increase the lifespan of the aging Mega Drive/Genesis system, which was facing stiff competition from the SNES...
and Saturn
Sega Saturn
The is a 32-bit fifth-generation video game console that was first released by Sega on November 22, 1994 in Japan, May 11, 1995 in North America, and July 8, 1995 in Europe...
consoles.
The only usage of the SVP was in the Mega Drive version of Virtua Racing
Virtua Racing
Virtua Racing or V.R. for short, is a Formula One racing arcade game, developed by Sega-AM2 and released in October 1992. Virtua Racing was initially a proof-of-concept application for exercising a new 3D-graphics platform under development, the "Model 1". The results were so encouraging, that...
. Its main task was to calculate the polygonal graphics
Polygonal modeling
In 3D computer graphics, polygonal modeling is an approach for modeling objects by representing or approximating their surfaces using polygons. Polygonal modeling is well suited to scanline rendering and is therefore the method of choice for real-time computer graphics...
of the game. The main purpose of the SVP is to render polygons as 8x8 tiles, which the game program transfers to VRAM from the 128K RAM area using DMA
Direct memory access
Direct memory access is a feature of modern computers that allows certain hardware subsystems within the computer to access system memory independently of the central processing unit ....
. The SVP runs at 23 MHz and can calculate 300 to 500 polygons/frame at 15 frames per second (up to 6,500 polygons per second) with a maximum of 16 colors. It also has its own small heat sink because it gets warm during operation.
Implementations
At the time of release, the SVP was set to raise the cost of the Virtua Racing cartridges (the game cost £Pound sterling
The pound sterling , commonly called the pound, is the official currency of the United Kingdom, its Crown Dependencies and the British Overseas Territories of South Georgia and the South Sandwich Islands, British Antarctic Territory and Tristan da Cunha. It is subdivided into 100 pence...
70 in the UK, and $100 in the U.S.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
), which can be seen as a major reason why the SVP was only used in Virtua Racing. Sega of America started to develop the 32X
Sega 32X
The Sega 32X, codenamed Project Mars, is an add-on for the Mega Drive/Genesis video game console by Sega. Its aim was to increase the lifespan of the aging Mega Drive/Genesis system, which was facing stiff competition from the SNES...
expansion console around that time.
Due to a clash between memory addresses used by the 32X and the SVP, Virtua Racing is the only Mega Drive game which doesn't run with an attached 32X. A 32X version of the game called Virtua Racing Deluxe was released later in 1994, featuring more polygons per track and car, three cars and two more tracks. It has been theorized by many that an SVP adapter (similar to the 32X) was in development prior to the 32X creation.
Emulation
An emulator called PicoDrive is capable of emulating the SVP, the source code is available.An emulator for the Wii
Wii
The Wii is a home video game console released by Nintendo on November 19, 2006. As a seventh-generation console, the Wii primarily competes with Microsoft's Xbox 360 and Sony's PlayStation 3. Nintendo states that its console targets a broader demographic than that of the two others...
console called Genesis Plus GX is able to emulate the SVP.
Also, an emulator called Regen, emulates the SVP.
As of version 3.6, the Kega Fusion Genesis/32x/CD emulator supports SVP emulation.