Game Genie (Mega Drive)
From Sega Retro
The Game Genie is a series of cheat cartridges designed by Codemasters and sold by Camerica and Galoob for the Nintendo Entertainment System, Super Nintendo Entertainment System, Game Boy, Sega Mega Drive/Genesis, and Sega Game Gear that modifies game data, allowing the player to cheat, manipulate various aspects of games, and sometimes view unused content and functions. Although there are currently no Game Genie products on the market, most video game console emulators feature Game Genie support. The Action Replay and GameShark hacking devices are similar devices.
Contents
Operation
The Game Genie attaches to the end of a cartridge and is then inserted into the cartridge port of the console for which it was designed. The loading mechanism of the NES makes the use of the NES Game Genie awkward, as game cartridges for the NES are inserted into the console, then depressed down into the console. The addition of the Game Genie causes the cartridge to protrude from the console when fully inserted, making the depression impossible. Therefore, the Game Genie was designed in such a way that it did not need to be depressed in order to start the game. However, this design made it very difficult to insert into a newer top-loading NES. An adapter was made to deal with the problem, but few were requested; today they are hard to find since the stock was liquidated.
Upon starting the console, the player may enter a series of characters referred to as a "code" or several such series that reference addresses in the ROM of the cartridge. Each code contains an integer value that is read by the system in place of the data actually present on the cartridge. The Game Genie cannot manipulate RAM, though it can make the console read different values from SRAM.
Because they patch the program code of a game, Game Genie codes are sometimes referred to as patch codes. These codes can have a variety of effects. The most popular codes give the player some form of invulnerability, infinite ammunition, level skipping, or other modifications that allow the player to be more powerful than intended by the developers. In rare cases, codes even unlock hidden game features that developers had scrapped and rendered unreachable in normal play (an example of this is the final Hidden Palace Zone in Sonic 2). Nonetheless, inputting a random code is as effective as using PEEK and POKE operations randomly. The results can yield a useful code, but will most likely result in anything from a mundane or highly unnoticeable change to freezing the game and possibly corrupting saved data. The Game Genie was usually sold with a small booklet of discovered codes for use with the system. However, these booklets would eventually become inadequate as new codes were discovered and new games were released that were not covered. To address this, an update system was implemented, where subscribers would receive quarterly booklet updates for a fee. In addition Galoob also ran ads in certain gaming publications (such as GamePro) that featured codes for newer games. Today, these codes and many others discovered by players can be found for free online.
It should be noted that the Game Genie would not work with Super Nintendo games that contain a performance enhancing chip (e.g. Super FX and S-DD1 chip) such as Star Fox, Super Mario World 2: Yoshi's Island, Street Fighter Alpha 2 and Doom. These game cartridges contain additional pins that insert into the slots located left and right of the main center slot. Cartridge adapters made before the release of Star Fox (the first game to need the expansion slots) like the Game Genie did not have a connection to these previously unused slots, so cartridges that contain an additional processor (and thus need to be connected to those slots to do I/O with the system) could not be plugged into these devices. However, some games with these extra contacts worked perfectly regardless, most notably Mega Man X2 and Mega Man X3.
On the Sega Mega Drive/Genesis, the Game Genie can function as a country converter cartridge since most of these games are only "locked" to their respective regions by the shape of the cartridges and a set of a few bytes in the header of the ROM.
Nintendo and the Game Genie
The introduction of the original NES Game Genie was met by fierce opposition from Nintendo. Nintendo sued Galoob in the case Lewis Galoob Toys, Inc. v. Nintendo of America, Inc., claiming that the Game Genie created derivative works in violation of copyright law. Sales of the Game Genie initially stopped in the U.S., but not in Canada. In many gaming magazines of the time, Camerica placed Game Genie ads saying "Thank You Canada!" However, after the courts found that use of the Game Genie did not result in a derivative work, Nintendo could do nothing to stop the Game Genie from being sold in the U.S. Sega, on the other hand, fully endorsed the product with their official seal of approval.
Around the time of the lawsuit with Galoob, Nintendo used other methods in attempts to thwart the Game Genie. Nintendo had made minor modifications to the NES and SNES systems that caused many games not to work with the Game Genie, with the addition of a lock-out chip designed to prevent other companies from making games for the NES without paying fees. This was done with little publicity. The only way one could tell is by the manufacture date or serial number. This is not to be confused with the later redesign of of top-loading consoles for the NES and the smaller, sleeker SNES. Nowadays, using emulators to play these games as ROM dumps on the computer with a software Game Genie will work as the pre-Game Genie consoles did.
Programming Your Own Codes
Codes listed on the Internet give you an idea of the kind of effects you can create by programming your own codes.
- The easiest way to make your own codes is to make slight changes in existing codes. In the next section, there are simple tables that show you how to change the codes you find to create effects you might enjoy.
- If you are making small changes to existing codes, you must have eight characters in the code.
- You can also program codes simply by using random characters. You must have eight characters in the code.
- Using two or more codes at the same time is a more difficult way to program random codes, since it's harder to tell which code is making the effect happen.
- Some kinds of codes are easier to program. The best ones are codes with numbers in them (number of lives, number of rings, minutes on the timer).
- Some kind of codes are harder to program, such as "infinite lives" or "super mega power."
- Many codes you create will have some effect, but often it will be such a small change that you will not notice any difference. You many have to try many random codes before you get an interesting effect.
- If you find a random code that has an interesting effect, then try changing it by using the program technique in the next section. This way, you are more likely to hone in on a really good effect.
Your success in code programming will depend a lot on luck. Keep trying! Of course, some of the effects you create you may not like. Almost any effect is possible — good, bad, interesting, annoying, fun or just plain silly.
If a code you program interrupts the game or causes an undesired effect, just turn the power off and then on again, and program different codes to play.
How to Program
There are two basic methods used to program your own codes by changing existing codes:
- Using Method 1, you change the 6th character of the code.
- Using Method 2, you change the 1st and/or 2nd character of the code.
Remember, these methods work best when the code you wish to change has numbers in it. They will usually not work on a code like "infinite rings."
The best way to proceed is to write down the original code, look up the choices in the tables below, and then write down all the variations underneath the original code. This way, you can return to your Game Genie with your own list of codes to try.
For both methods, refer to the table below. Find the character you want to change in one of the columns, then substitute one of the letters in the same column.
| Column 1 | Column 2 | Column 3 | Column 4 |
|---|---|---|---|
| A | B | C | D |
| E | F | G | H |
| J | K | L | M |
| N | P | R | S |
| T | V | W | X |
| Y | Z | 0 | 1 |
| 2 | 3 | 4 | 5 |
| 6 | 7 | 8 | 9 |
External Links
- Gamegenie.com - An unofficial codes site which uses the Game Genie name
- GSHI - Complete collection of Official Game Genie codes