A cartridge game of the 1980s usually had nowhere to keep a saved game. Its program sat in ROM, and anything in the console’s RAM vanished when the power went off. Adding memory that survived meant a RAM chip and a battery in every cartridge. The cheaper answer was to make the player the storage: when the game ended, it printed a code that described where they had got to, and the player copied it onto paper. Nintendo Power’s advice on one early example sums up the experience: “When you get a password after visiting a treasure room, make sure that you write it down in case you want to go back there.”
Fast facts
- What it is: the game’s state (level or room, items, lives, bosses beaten) packed into a short code, with a check so that mistyped codes are rejected.
- Forms: letters and digits (Metroid’s 24 characters, Super Hang-On’s 14 on the Mega Drive); symbols (Castlevania II and its Game Boy sequel); a grid of dots (Mega Man 2’s 5×5).
- The alternative: battery-backed memory in the cartridge. By 1988 Nintendo’s The Legend of Zelda had “a built-in five year battery to save games”; in 1992 publishers were still choosing between the two game by game.
- The weakness: anything that can be decoded can be written. Nintendo Power printed the rules for building any Mega Man 2 password in 1990, and Metroid’s JUSTIN BAILEY is a valid password that nobody at Nintendo wrote.
In the listings
When Nintendo Power launched in 1988, a password was still worth a mention in a preview: Capcom had “packed this new game”, 1943, “with high action and a new password feature”. In Bubble Bobble “A password feature allows you to continue or stage select your favorite level”; in Legacy of the Wizard the grandmother of the hero, Loias, gave out passwords. From early 1991 the magazine’s game listings recorded for every title whether it used “a battery or password to save game play data”, and the two ran side by side for years. In May 1992 it noted that “Jack Nicklaus Golf uses a password to save your position and True Golf Classics: Pebble Beach Golf Links employs a battery backup”.
The forms varied. Konami’s Castlevania games used symbols, and the Game Boy Castlevania II: Belmont’s Revenge kept them: “The Password symbols are like those used in Castlevania II for the NES, so record each symbol carefully.” On the Mega Drive, Super Hang-On took a fourteen-character string, and a British tips page in 1990 printed one, GFF3F546F35564, that set the player’s credits to “$9,999,999,900”.
Mega Man’s grid
Capcom’s Mega Man 2 replaced characters with a picture: a 5×5 grid in which the player marks nine squares. In May 1990 Nintendo Power announced “The code has been cracked!”, and its explanation shows how a password is put together. “The top row of a valid password always has one mark and the position of that mark dictates the number of Energy Tanks that Mega Man will have. The positions of the other eight marks determine which weapons Mega Man will possess.” Each of the eight Robot Masters had a pair of squares: “Enter the top position to obtain the weapon. The bottom position contains no weapon.”
So the nine dots hold one choice out of five (the Energy Tanks) and eight yes-or-no answers (which bosses are beaten). Once the table was printed, a reader could start the game in any state they liked. The grid carried over to the Game Boy, where Computer and Video Games’ GO! section called it “A dotty way to pass”: “A grid appears, into which you enter dots.”
Metroid and JUSTIN BAILEY
Metroid shows what the technique cost. In Japan it was a 1986 Famicom Disk System game that saved to the disk. On cartridge in the West, as Retro Gamer put it, it “had a complex password system” instead: 24 characters, shown on two lines when the game was over. Players who got stuck could reach that screen deliberately. Nintendo Power was still printing the trick in 1994 for anyone “trapped in the mazes of the original Metroid without any escape”: pause the game on controller I, then “press Up and A on Controller II”.
A published disassembly of the NES program shows how those 24 characters work. Each character carries six bits, so the password holds 18 bytes. Sixteen of them record the game’s state, much of it bit by bit: items picked up, Samus’s equipment, her missile count, whether Kraid and Ridley are beaten, the area to start in, and whether she is wearing her suit. The seventeenth is a random number, and the sixteen state bytes are rotated that many bits, so the same game produces different-looking passwords. The last byte is a checksum: the sixteen state bytes and the random byte added together, keeping only the low eight bits. When a password is typed in, the game undoes the rotation, adds up the bytes again and accepts the password if the totals match.
That check catches typing mistakes, but it is not a secret. A string chosen at random has about one chance in 256 of passing, and every one that passes is a real save. JUSTIN BAILEY, padded out with dashes, is one of them. In October 1991 Nintendo Power mentioned it in passing: “JUSTIN BAILEY is the top half of a code that lets you begin with full missiles and six tanks.” Its 1997 retrospective of famous codes gave the full recipe: “Enter ‘JUSTIN BAILEY’ as your password, with all dashes on the second line. You’ll start the game with 6 Energy Containers, 255 Missiles and the Wave Beam. In addition, Kraid and Ridley will be defeated, and Samus will exchange her armor for a spiffy new costume.” “Whoever Justin Bailey was,” it added, “we can thank him.”
The code travelled. Tips pages printed it in K in Italy in May 1991, in Pixel in Greece that October and, from a reader in Cardiff, in Computer and Video Games in Britain in January 1992. In 1999 a Nintendo Power reader suggested that “a ‘bailey’ was slang for a bathing suit in the 1920s”, so the phrase meant “just in bailey”, and the editors replied “You’re probably right.” The program itself suggests a plainer answer. The only password it checks for by name is NARPASSWORD, a debugging code that makes Samus invincible and refills her every frame; a fanzine reported in 2004 that players who had studied the code found “only one intentionally programmed password”, and that the others, “even the now famous JUSTIN BAILEY code, are purely coincidental”. The disassembly names the suit flag JustInBailey, after the code that made it famous.
Codes and cheats
The same mechanism served players who wanted to save and players who wanted to cheat, and by the late 1990s the second use had taken over the first in the magazines’ memory. Nintendo Power’s hundredth issue filed JUSTIN BAILEY among “the coolest weapon codes ever”, next to button sequences that had been put in on purpose. See cheat codes and battery backup for the two things the password sat between.
Sources
- Nintendo Power issue 1, July–August 1988: 1943 preview (“a new password feature”).
- Nintendo Power issue 3, November–December 1988: Bubble Bobble, Legacy of the Wizard and Anticipation (the treasure-room password).
- Nintendo Power issue 12, May 1990, “Classified Information”: the Mega Man II password grid.
- Nintendo Power issue 21, February 1991, and issue 29, October 1991: game listing key (“a battery or password to save game play data”); issue 29 also Castlevania II: Belmont’s Revenge and JUSTIN BAILEY.
- Nintendo Power issue 36, May 1992: Jack Nicklaus Golf and Pebble Beach Golf Links.
- Nintendo Power issue 56, January 1994: the Metroid password-screen trick.
- Nintendo Power issue 100, September 1997: JUSTIN BAILEY in a retrospective of codes.
- Nintendo Power issue 116, January 1999: reader’s letter on “bailey”.
- Zero issue 11, September 1990: Super Hang-On (Mega Drive) password.
- Computer and Video Games GO! supplement, issue 127, June 1992: Game Boy Mega Man password grid.
- K (Italy), Speciale Console supplement to issue 28, May 1991; Pixel (Greece) issue 81, October 1991; Computer and Video Games issue 122, January 1992: JUSTIN BAILEY in readers’ tips.
- Retro Gamer issue 16, 2005: the Famicom Disk System, and Metroid’s Western password.
- Old Skool Games issue 1, March 2004: NARPASSWORD.
- Antic vol. 6 no. 11, March 1988: The Legend of Zelda’s “five year battery”.
- nmikstas, metroid_disassembly (annotated disassembly of the NES Metroid, building on Kent Hansen’s earlier work), Bank00.asm and Bank07.asm: password encoding, rotation, checksum and NARPASSWORD (web, secondary). https://github.com/nmikstas/metroid-disassembly