Heres a new release of an emulator that supports the 8 bit consoles and handhelds from Sega:

Sega Master System, Sega Game Gear, SG-1000 and ColecoVision emulator has been updated. No change log available.
File: Download
News source: http://benryves.com

via http://forum.emu-russia.net/viewtopic.php?f=26&t=6971