Namco System 246
The Namco System 246 is a development of the Sony PlayStation 2 technology as a basis for an arcade system board. It was released in 2001 on its first game Ridge Racer V. Like the Sega NAOMI, it is widely licensed for use by other manufacturers. Games such as Battle Gear 3 and Capcom Fighting Evolution are examples of System 246-based arcade games that are not Namco products.
Specifications
Main CPU: MIPS III R5900 Emotion Engine 128-bit RISC operating at 294.912 MHz
Sub CPU: MIPS II R3000A IOP with cache at 33.8688 MHz (Unlike the PSXCPU)
System memory: 32 MB Direct Rambus
Graphics: "Graphics Synthesizer" operating at 147.456 MHz
Sound: "SPU1+SPU2"
Media: CD-ROM, DVD-ROM, Hard Drive, 64MBit 3.3V NAND FlashROM Security Dongle
Namco System 256 is an upgraded version of 246 but the upgrades are unknown (more ram and faster cpu speeds likely)
Namco Super System 256 is the same as regular Namco System 256 but it has the gun board integrated.
Namco System 147 is similar to 246 but does not use a DVD-rom, instead it has rom chips on the system board.