The 32x debuted in 1994. It was an add-on for the Genesis. It connects to the Genesis by plugging-in the unit into the Genesis's cartage port. It is said that the 32x increase the speed of the unit by 19x! This increase in performance is possible thanks to its 2 RISC based processors.
The Sega 32X added better color (finally), faster performance, and 3D graphics to the Genesis and Sega CD. The whole idea is sort of strange considering that when you get the Genesis and attach a Sega CD and the 32X you now have a huge chunk of hardware worth well over $400 with massive parallel processing power that still pales in comparison to say a Saturn. Still, the whole thing wasn't too bad with some great translations like Virtua Racing Deluxe and Virtua Fighter. The system had a few notable titles released before it's quick demise at the release of the Saturn and Playstation.
The idea of emulating every aspect of the 32X is quite a challenge. You'd have to emulate both the Genesis and the Sega CD first, and then write up your SH-2 core and God knows how the 32X sound processor works. The 32X is another case of someone reverse-engineering the hardware to gain the knowledge to emulate the machine. Even though the 32X, (for the most part) takes over the Genesis unit, it still allows you to play Genesis games by passing through the data from the 32x to the Genesis unit.
Quick Specs List:
Processor: Dual Hitachi SH2 RISC Processors (one master and one slave)
operating at 23Mhz each
Co-Processor: 68000, Z80, VDP (Genesis) 68000 (Sega CD)
Data Path width: 32-bits within 32X
Color Palette: 32,768
On screen: 32,768
3D Capabilities: 50,000 Texture Mapped Polygons per second
Sound: Stereo PCM plus an extra 2 channels to the Genesis and Sega CD
Ram: extra 512 Kilbytes for the Genesis and Sega CD
Cart Size: 16 - 32 Megabit