Released (by Amstrad, naturally) some time in the early 90s, this was an ill-conceived combination of an Amstrad PC and a Sega Megadrive (Genesis if you're American). The Megadrive was actually a separate circuit board mounted inside the case of a low quality PC, and wired up to share the multi-sync monitor and speakers of the PC, with no other shared components.
Megadrive games were playable using a cartridge slot to the left of the PCs casing which was activated by a sliding door contraption which meant that the machine could either be used for PC floppies or Megadrive cartridges depending on the position of the door. It was not possible to utilise the PC and Megadrive functions simultaneously.
This all seems like a (semi-)reasonable idea until you consider the fact that the cartridge slot was not exactly the same size as that of the MegaDrive and so the device refused to accept the (strangely shaped) EA cartridges. Also, the specifications of the PC were pretty pathetic, even for the time, especially when a standalone Megadrive and 'high-end' PC (read 486) could be bought seperately for only slighty more than the MegaPC. Those specifications are:
Processor: Intel 80386SX running at 25Mhz.
Hard disk: 40/80MB.
Monitor: 14" Dual-Sync.
Due to the low-spec PC and the incompatible Megadrive, this system sank without a trace almost immediately and is almost unknown.
I believe the system came with MS-DOS 5.0 and the (godawful, but probably better than Windows) Amstrad Desktop.
In my younger days I was actually given one of these things for free (albeit monitorless), however, being very young and even more foolish, I discarded it after being unable to get hold of a monitor. Idiot. I'd love to poke around inside one of these things some day but, sadly, I don't think it will ever happen. Does anyone have a picture of one of these things, or even better, know where I can buy one?