Game Genie | Code Like It's 198x

The Game Genie let a Nintendo owner type in a six-letter word and start a game with infinite lives. It did it without touching the game’s memory or stopping the processor. It sat between the console and the cartridge and, for up to three addresses, gave the console a different byte from the one the cartridge held. Code Masters, the British budget-software house, designed it. The American toy company Lewis Galoob sold it, and Nintendo went to court to stop Galoob selling it. Nintendo lost, and in 1992 it was ordered to pay Galoob $15 million.

Fast facts

Designed by: Code Masters: Ted Carron with Richard and David Darling
Sold by: Camerica in Canada, Galoob in the United States, Hornby Hobbies in Britain
First sold: 1990 in Canada, where 100,000 were sold that year
Versions: NES, Mega Drive, Game Boy and Super NES
Court case: Lewis Galoob Toys v. Nintendo of America, decided for Galoob in July 1991 and upheld on appeal in 1992

From Power Pak to Genie

Code Masters had been thinking about cheats for its own cartridges. “We were thinking of adding switches to the actual cartridges so you could select the amount of lives available and things like that,” Richard Darling told Edge in 1996. “We thought it would be novel if you could do it for a game but better if we could come up with some sort of attachment that worked on any title.” The engineer Ted Carron built it. Edge’s 2004 history of Micro Machines calls the prototype Carron’s “Power Pak”. David Darling renamed it the Game Genie because players could enter three codes, or “wishes”, at a time. The American patent for the device, filed in May 1990, names Richard Darling, Edward A. Carron and David Darling as its inventors.

Code Masters showed the device at the Consumer Electronics Show in Chicago, where a talent scout from Galoob “loved it”, Richard Darling said. Galoob licensed it for the United States. In Canada, Camerica made and sold it. Game Informer called Camerica the Genie’s “Canadian owner and manufacturer”, and a Camerica feature in 1992 described it as “the company that brought you Game Genie”. The design was Code Masters’ own: its British advertising said “INVENTED BY CODEMASTERS”. Camerica was a separate, Canadian company that also published Code Masters’ unlicensed NES games in North America.

How it worked

Plug the Genie into the NES, plug a game into the Genie and switch on. Instead of the game, the Genie’s own code-entry screen appears. You type in up to three codes from the codebook and press Start, and the game begins with the changes in place. Mean Machines, reviewing it in 1992, found codes for infinite lives, time and energy, codes to start on later levels, and oddities such as “super bounce on the cars in Micro Machines” or stopping the vitamin capsules falling in Dr. Mario.

Behind that screen the Genie is doing something simple. The NES reads its program from the cartridge ROM at CPU addresses $8000 to $FFFF. The Genie passes those reads through, except at the addresses it has been told to watch. The NESdev Wiki, the community reference for NES hardware, puts it this way: “It can intercept any three addresses in CPU $8000…$FFFF and respond with a single replacement for each.” If a game loads its starting lives with an instruction whose operand is 3 and the Genie answers 9 whenever that byte is read, the game starts with nine lives. The program has not been changed. The console has simply been given a different byte.

The start-up is a two-stage trick. At power-on the Genie presents its own 4 KB ROM to the console, which runs the code-entry screen. Pressing Start writes the codes into the Genie’s registers and then switches it into game mode, where it passes the real cartridge through. It stays in that mode until the console is switched off.

The codes

A Game Genie code is written in a 16-letter alphabet (A P Z L G I T Y E O X U K S V N), and each letter stands for four bits. Six letters give 24 bits. That is enough for a 15-bit address inside the $8000 to $FFFF window and the 8-bit replacement value.

Eight-letter codes add an 8-bit compare value, and the Genie replaces the byte only if the cartridge’s own byte matches it. The reason is bank switching. Many NES cartridges swap different banks of ROM into the same addresses, so an unconditional code could fire in the wrong bank and corrupt something unrelated. The compare value makes that much less likely. The patent describes the same safeguard: the data is changed “only if the data from the external data storage medium matches data set by user-operable input means”.

Owners could not search for codes themselves on the NES version. As Mean Machines put it, “Since you can’t actually hack into the games yourselves, you’re forced to rely on further code sheets.” New codes came from the publishers. In Britain, Hornby and Code Masters ran a telephone helpline for them, and magazines printed codes sent in by readers.

Nintendo v. Galoob

Nintendo’s case was that the Genie infringed its copyrights. Brian Moore of Serif, Nintendo’s UK distributor, told ACE in 1990 that “the designers of games spend a long time getting everything right”, and said the Genie infringed their copyright. Game Informer reported Nintendo’s argument that changing a game’s rules would make it boring, so that fewer games would be sold. Galoob and Camerica replied that the Genie would “breathe new life into old games”.

Nintendo sued in the United States and in Canada, where it tried to get an injunction against Camerica. In the United States it won a preliminary injunction that stopped Galoob selling the Genie until the trial in the spring of 1991. In Canada it did not, and Camerica went on selling. In July 1991 US District Judge Fern Smith ruled for Galoob. The Ninth Circuit Court of Appeals upheld her decision in May 1992. It held that the Genie’s changes were not fixed in any permanent form, so they did not create a derivative work. It also held that players using the Genie at home were making fair use of games they had bought.

Nintendo had posted a bond when it obtained the injunction. In 1992 Judge Smith ordered Nintendo to pay Galoob $15 million for the sales it had lost while the Genie was kept off the market for a year, as Game Informer reported that September. Edge said in 1996 that the money was paid from the bond, and that about $3.5 million of it went to Code Masters as the Genie’s creator. “I am overjoyed. We were not intimidated by Nintendo’s aggressive legal behaviour,” David Darling said at the time. The Game Genie, he added, “proves that innovation cannot be stifled”.

Sales and later versions

The injunction did not stop the Genie selling well once it was lifted. In January 1992 Mean Machines said it had sold more than a million units, and Edge later put its American sales at some 1.4 million. Richard Darling remembered it as “America’s fifth-best-selling toy that year”.

Sega took the opposite view to Nintendo. It gave the Mega Drive Genie its Seal of Quality, Mean Machines reported in February 1992, and the NES and Mega Drive versions reached British shops in July 1992, at £39.99 and £44.99. A Game Boy Genie, which Code Masters showed as a prototype at the Consumer Electronics Show in 1992, clipped onto the handheld and had a button to switch the codes on and off during play. An American Super NES version was on sale by the start of 1993. For Britain, Galoob and Hornby restyled its case to suit the European console, and set a price of £44.99 for a June 1993 release.

Sources

ACE issue 35, August 1990: “Nintendo gets tough with cheat machine” (Galoob in the US, Code Masters as designer, the Serif statement).
Game Informer issue 1, Fall 1991: the District Court ruling for Galoob, the earlier injunction, Camerica as the Genie’s “Canadian owner and manufacturer”, Canadian sales, and the arguments on each side (the Canadian hearings and the US injunction).
Game Informer issue 4, March 1992: Camerica feature (“the company that brought you Game Genie and Micro Machines”).
Game Informer issue 5, June 1992: CES report (Game Boy Game Genie prototype).
Game Informer issue 6, September 1992: “Nintendo vs. Game Genie: The Final Chapter?” (Judge Fern Smith’s $15 million order; the year-long injunction, lifted in July 1991).
Mean Machines issue 16, January 1992 (over 1,000,000 sold in America; code sheets); issue 17, February 1992 (Sega’s Seal of Quality); issue 22, July 1992, Game Genie review (codes, prices, the Hornby helpline).
Mean Machines issue 24, September 1992: Game Genie advertisement (“INVENTED BY CODEMASTERS”, distributed in the UK by Hornby Hobbies).
GamesMaster issue 1, January 1993 (the American Super NES Game Genie) and issue 5, May 1993 (the UK Super NES version, £44.99, June).
Edge issue 35, August 1996: “Company focus: CodeMasters” (Richard Darling on the Genie’s origin, CES and “fifth-best-selling toy”; the $15 million award, the bond and Code Masters’ share; David Darling’s statement; 1.4 million American sales).
Edge issue 136, May 2004: “The making of… Micro Machines” (Ted Carron’s Power Pak, the name and the three “wishes”, Galoob’s licence).
US Patent 5,112,051, “Interfacing device for a computer games system”, Richard Darling, Edward A. Carron and David Darling, filed 30 May 1990, granted 12 May 1992 (data substitution and the compare safeguard). https://patents.google.com/patent/US5112051A/en
NESdev Wiki, “Game Genie” (web, secondary): the three intercepted addresses, the compare value and bank switching, the start-up and game mode. https://www.nesdev.org/wiki/Game_Genie
Benzene, “NES Game Genie Code Format DOC” v0.71, 1997 (web, secondary): the letter values and the six- and eight-letter layouts. https://www.nesdev.org/nesgg.txt
Lewis Galoob Toys, Inc. v. Nintendo of America, Inc., 964 F.2d 965 (9th Cir. 1992), as summarised by Wikipedia (web, secondary): the appeal date, the fixation and fair-use holdings, and the Canadian case. https://en.wikipedia.org/wiki/Lewis_Galoob_Toys,_Inc._v._Nintendo_of_America,_Inc.