Metal Gear Password Guide For NES

Before the mind-blowing graphics of modern day video game consoles such as the PlayStation series and whatnot, gamer from the 90s generation were enjoying the Nintendo Entertainment System or commonly called as NES. Developed and manufactured by Nintendo, this gaming console was initially released as Family Computer in Japan. One of the best titles during the days of yore is Hideo Kojima's Metal Gear. Some peeps from the younger generation, who has not yet seen a Nintendo Entertainment System gaming console may find this hard to believe. You cannot consider yourself a real Metal Gear fan if you have not played its great NES version. There are hundreds of websites you can find in Google that would still allow you to play good old NES games, and one of them is Game-Oldies. The Non-Technical Technical Support is not in any way associated with Game-Oldies.

This article should help us understand how Metal Gear (NES) passwords are produced according to Doug Babcock's analysis as presented on GameFAQs way back 2005. Once we have learned how the whole idea works, perhaps we can try it on Game-Oldies' Metal Gear NES page.

The Password Table

The Nintendo Entertainment System version of Metal Gear accepts 25 character password, and the code contains the information on which part of the game you have accomplished and whatnot. According to Mr. Babcock's cool guide, the easiest way to compute for a password is by creating some kind of password table that goes like this:

TankBull TankShotgunnerTwin ShotMachineGunKid
M. GunMissileExplosiveMineHand Gun
Prisoner #1Prisoner #2Prisoner #3Prisoner #4Prisoner #5
Prisoner #6Prisoner #7Prisoner #8Prisoner #9Prisoner #10
Prisoner #11Prisoner #12Prisoner #13Prisoner #14XXXXXXXXXXXXX
B.B. SuitCardboardBinocularsGasmaskCigarettes
Hand Gun+16Hand Gun+8Hand Gun+4Hand Gun+2Hand Gun+1
M. Gun+16M. Gun+8M. Gun+4M. Gun+2M. Gun+1
Grenade L.+16Grenade L.+8Grenade L.+4Grenade L.+2Grenade L.+1
Rocket L.+16Rocket L.+8Rocket L.+4Rocket L.+2Rocket L.+1
Grenade L.+64Grenade L.+32M. Gun+128M. Gun+64M. Gun+32
GogglesUniformCoward DuckFire TrooperArnold
OxygenCompassSilencerRocket L.Grenade L.
Captured!XXXXXXXXXXXXXXXXXXXXXXXXXXPrisoner #15Prisoner #16
Hand Gun+64Hand Gun+32Prisoner #17Prisoner #18Prisoner #19
GloveTransmitterPrisoner #20Prisoner #21Prisoner #22
Equip. RecovHand Gun+128Card8Card7Card6

Most items shown in the table above can have a value of 1 or 0, on or off in binary. If an item's value is 1, it means that:
  • Enemy boss(es) is/are beaten by Snake (if the item represents an enemy boss). The enemy bosses in this game are VermonCaTaffy, SuperComputer, Tank, Bull Tank, Shotgunner, Twin Shot, and MachineGunKid.
  • They were acquired by Snake (if the item(s) is/are a weapon(s), ammo, or euqipment). Examples are M. Gun or Machine Gun, Missile, Explosive, Mine, Hand Gun, Access Cards and so on.
  • They were saved by Snake (if the item is/are prisoner(s)). Snake needs to save a total of 22 prisoners in this Nintendo Entertainment version of Metal Gear.
  • No value (if it shows XXXXXXXXXXXXX).
  • Additional item(s) or ammo (if it show a "+" and a number beside it). Examples are Rations+8, Hand Gun+128, Rocket L.+1 and so on.
  • Snake is captured (if it shows Captured!). Snake would need to escape his prison cell to beat the game.

The first line on the table for example; VermonCaTaffy, SuperComputer, Rank+4, Rank+2, Rank+1. Five (5) items and each item can be represented by 1s or 0s. Let's say the outcome of the password that we want to have is:
  1. VernonCaTaffy and the SuperComputer is beaten.
  2. Snake has achieved the highest rank in the game, which is Rank 4.
We just need to set the values of VernonCaTaffy, SuperComputer, and Rank+4 into 1s while Rank+2, and Rank+1 values into 0s. Based on the items arrangement on the table, we will produce the value "11100". Each 5 digit binary value we will produce will have a corresponding letter or number value. Thus, the 11100 we produced will have the value "W" based on Doug Babcock's "Bits-to-digit key" table shown in the guide he submitted to GameFAQs.
00000: 1
00100: 5
01000: C
01100: G
10000: K
10100: O
11000: S
11100: W
00001: 2
00101: 6
01001: D
01101: H
10001: L
10101: P
11001: T
11101: X
00010: 3
00110: A
01010: E
01110: I
10010: M
10110: Q
11010: U
11110: Y
00011: 4
00111: B
01011: F
01111: J
10011: N
10111: R
11011: V
11111: Z

We need to do the step mentioned to all the twenty four (24) rows shown on the password table above. You should also get twenty four (24) five (5) digit binary values. The 25th character will serve as the checksum.
Metal Gear for Nintendo Entertainment System passwords are divided into five (5) groups and each group bearing five (5) characters. The password table shows that the 25th row is blank. The reason being is that the last character is reserved to carry the value of the "checksum". Google defines checksum as a digit representing the sum of the correct digits in a piece of stored or transmitted digital data, against which later comparisons can be made to detect errors in the data. Doug Babcock's explanation on how to compute for the checksum goes this way:
  1. We need to convert the first twenty-four (24) characters into numbers. We need to check the "Last Digit Value conversion key" shown in Doug's GameFAQs' guide to do this.
    '1': 0
    '5': 4
    'C': 8
    'G': 12
    'K': 16
    'O': 20
    'S': 24
    'W': 28
    '2': 1
    '6': 5
    'D': 9
    'H': 13
    'L': 17
    'P': 21
    'T': 25
    'X': 29
    '3': 2
    'A': 6
    'E': 10
    'I': 14
    'M': 18
    'Q': 22
    'U': 26
    'Y': 30
    '4': 3
    'B': 7
    'F': 11
    'J': 15
    'N': 19
    'R': 23
    'V': 27
    'Z': 31
  2. Add all the numbers you got after the conversion.
  3. If the sum you got on the 2nd step is greater than five hundred seven(507); add two (2) to it. Let's say you got 508 and 508 is greater than 507, we then add two (2) to it. Thus, 508 + 2 = 510.
    However, if the sum is greater than two hundred fifty two (252) but not greater than five hundred seven (507); just add one (1) to it. Let's say you got 253 and 253 is greater than 252 but lesser than 507, we then add one (1) to it. Thus, 253 + 1 = 254.
  4. On top of whatever result you got on the 3rd step, add another seven (7) to it. Based on the example values above, 510 + 7 would be 517.
    254 + 7 would be 261.
  5. If the result you got from the 4th step is thirty two (32) or greater than thirty two (32); keep subtracting thirty two (32) from it until you get a result that is less than thrity two (32).
  6. Once you get a value that is less than thirty two (32), convert this into its respective final value using the "Last Digit Value conversion key" table shown on the 1st step. This will now be your 25th password character and your checksum.

Password Not Working?

According to Bob, these conditions must be met for your Metal Gear passwords to work:
  • The least rank we can have for Snake is 1.
  • The highest rank we can have for Snake is 4.
  • We are only allowed to set the maximum number of mines to 20.
  • We are only allowed to set the maximum number of explosives to 20.
  • We are only allowed to set the maximum number of missles to 20.
  • We are only allowed to set the maximum number of grenade launcher rounds to 90.
  • We are only allowed to set the maximum number of rocket launcher rounds to 30.

Alternative Way, Anyone?

To make things easier and more enjoyable, I decided to encapsulate Doug Babcock's concept into a tool written in Java. This should help us produce passwords for the Nintendo Entertainment System version of Metal Gear. Once again, we can try it on Game-Oldies' Metal Gear NES page. Last but not least, never consider yourself a true Metal Gear fan if you have not played this game yet!

Defeated Colonel Vermon CaTaffyDefeated Super ComputerSolid Snake's Rank +4Solid Snake's Rank +2Solid Snake's Rank +1
Defeated TankDefeated Bull TankDefeated ShotgunnerDefeated Twin ShotDefeated Machine Gun Kid
Have Machine GunHave MissileHave ExplosiveHave MineHave Hand Gun
Rescued Prisoner #1Rescued Prisoner #2Rescued Prisoner #3Rescued Prisoner #4Rescued Prisoner #5
Rescued Prisoner #6Rescued Prisoner #7Rescued Prisoner #8Rescued Prisoner #9Rescued Prisoner #10
Rescued Prisoner #11Rescued Prisoner #12Rescued Prisoner #13Rescued Prisoner #14Always OFF 1
Have Card #5Have Card #4Have Card #3Have Card #2Have Card #1
Have Bomb Blast SuitHave CardboardHave BinocularsHave GasmaskHave Cigarettes
Have LightHave AntidoteHave AntennaHave ArmourHave Detector
Always OFF 2Have 8 RationsHave 4 RationsHave 2 RationsHave 1 Rations
Have 16 Hand Gun AmmoHave 8 Hand Gun AmmoHave 4 Hand Gun AmmoHave 2 Hand Gun AmmoHave 1 Hand Gun Ammo
Have 16 MissilesHave 8 MissilesHave 4 MissilesHave 2 MissilesHave 1 Missiles
Have 16 ExplosivesHave 8 ExplosivesHave 4 ExplosivesHave 2 ExplosivesHave 1 Explosives
Have 16 MinesHave 8 MinesHave 4 MinesHave 2 MinesHave 1 Mines
Have 16 Machine Gun AmmoHave 8 Machine Gun AmmoHave 4 Machine Gun AmmoHave 2 Machine Gun AmmoHave 1 Machine Gun Ammo
Have 16 Grenade Launcher AmmoHave 8 Grenade Launcher AmmoHave 4 Grenade Launcher AmmoHave 2 Grenade Launcher AmmoHave 1 Grenade Launcher Ammo
Have 16 Rocket Launcher AmmoHave 8 Rocket Launcher AmmoHave 4 Rocket Launcher AmmoHave 2 Rocket Launcher AmmoHave 1 Rocket Launcher Ammo
Have 64 Grenade Launcher AmmoHave 32 Grenade Launcher AmmoHave 128 Machine Gun AmmoHave 64 Machine Gun AmmoHave 32 Machine Gun Ammo
Have GogglesHave UniformDefeated Coward DuckDefeated Fire TrooperDefeated Arnold
Have OxygenHave CompassHave SilencerHave Rocket LauncherHave Grenade Launcher
Snake is capturedAlways OFF 3Always OFF 4Rescued Prisoner #15Rescued Prisoner #16
Have 64 Hand Gun AmmoHave 32 Hand Gun AmmoRescued Prisoner #17Rescued Prisoner #18Rescued Prisoner #19
Have GloveHave TransmitterRescued Prisoner #20Rescued Prisoner #21Rescued Prisoner #22
Equipment RecoveredHave 128 Hand Gun AmmoHave Card #8Have Card #7Have Card #6


Reference(s) / Test Environment(s):

  1. Doug Babcock's Metal Gear Password Guide for Nintendo Entertainment System.
  3. Javascript tool written by Erickson Deveza.

Metal Gear Password Guide For NES Metal Gear Password Guide For NES Reviewed by Admin Moronman on 8:22 AM Rating: 5

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