Sega's consoles have a long history of storied, classic games that go right back to the dawn of the computer gaming age. Such classics as the Phantasy Star series, the birth of the Sonic the Hedgehog franchise, right up to the sheer open world awesomeness of Shenmue have delighted gamers the world over for years. Though the consoles themselves are no longer made or supported, it is still possible to play your old collection of Sega classics with the use of console emulator software.
First, some legal bits: It's not yet illegal to have and run a console emulator. The trouble is in getting the ROMs for games that you want to run on the emulator. While it's legal for owners of a game to personally create an archival backup copy of a game, it isn't legal to get ROMs or image files off the net, even if you legally own a copy of the game. You have to own the game yourself, and make the copy yourself. That's toughest on the cartridge games, but with Sega CD and Dreamcast games, it's not too hard to get software like ImgBurn that lets you personally rip iso files from your original discs.
Again: It's only legal for you personally to make ROM or image copies of a game you own. It's illegal to download, share, or host ROM or image files of the games themselves.
(EDITOR'S NOTE: Main source for this writeup can be found here.)
One of the better emulators out there for a broad range of Sega systems such as the Sega Master System, Sega Genesis/Megadrive, and Sega CD is Fusion, aka KEGA Fusion, a stable, reliable emulator for many of Sega's cartridge-driven consoles. Download it here, and we'll give you a quick run through for playing your classic gameson this console emulator.
Fusion starts you off with a rather unwelcoming screen of white noise, which distracting at first, until you realize that this is pretty much what your TV screen's AV-input channel looked like before you powered up your console. Accessing the File menu allows you to select the console you want to emulate as well as the specific ROM file from your basic Windows file browser. You can also boot a Sega CD disk, or load up a disk image from the File menu. Another feature to take note of here is the ability to "Save State," effectively taking a snapshot of the system state. This allows you to save and reload gameplay even if the game doesn't normally support this.
Other settings you'll want to look at include the Video menu, which allows you to set a custom screen size and tweak graphics and emulation settings. In order to define the control scheme, you'll want to go to Options -> Set Config -> Controls. From there, you can select control devices you want to emulate, as well as define the specific buttons for your keyboard or gamepad.
Now that you know how to load up ROMs and tweak the control scheme, you should be able to play just about any game for the Master System, Genesis/Megadrive, or Sega CD that you've got in your collection. Fusion is an internet favorite because of its ability to play a broad range of Sega consoles, while also being easy to use.
On display here for example, is a screenshot from the cyberpunk adventure game Snatcher. Snatcher is a near-future detective story with more than a little whiff of Blade Runner and Terminator.
Gen32 is another good choice for Genesis/MegaDrive, 32x and Sega CD emulation, though it doesn't support older machines like the Master System. Click on the download link on the Gen32 download emulator above and we'll show you how to get this beast running.