"Snake's Revenge" for NES
Rank, Weapon, Boss guide, v1.1 (8/5/2008)
by Dammit9x
dammit9x at hotmail dot com

Copyright 2008

    This document may be not be reproduced under any circumstances except for 
personal, private use. It may not be placed on any web site or otherwise 
distributed publicly without advance written permission. Use of this guide on 
any unauthorized web site or as a part of any public display is strictly 
prohibited and a violation of copyright.

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v1.0 (7/15/2008): Initial version

v1.1 (8/5/2008): Expanded sections 2, 6, 7 and 8 and added section 9
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TABLE OF CONTENTS

INTRODUCTION
1. RANK
2. HOSTAGES AND OFFICERS
3. STEALTH
4. ALARMS
5. ITEM DROPS
6. ITEM CAPACITY
7. ENEMIES AND BOSSES
8. MEMORY ADDRESSES
9. BONUS
CLOSING

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INTRODUCTION
  This guide lays out various data for Snake's Revenge which has previously been
unavailable. It is intended to help power players understand the inner workings 
of the game. Use it with your favorite walkthrough.

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1. RANK
  Snake's RANK, denoted by the number of stars, determines the size of his LIFE 
bar and how many items he can carry. RANK increases as Snake rescues hostages 
and interrogates officers with TRUTH GAS.

       |      |  Required cumulative   |
RANK   | LIFE | rescues/interrogations |
-------+------+------------------------+
*      |   6  |        0               |
**     |   8  |        4               |
***    |  10  |        9               |
****   |  12  |       14               |
*****  |  14  |       19               |
****** |  14  |       22               |

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2. HOSTAGES AND OFFICERS
  The table shows how many of each are available in each segment of the game. 
Once Snake has entered the next segment, he can't go back. Only officers and 
regular hostages (genuine hostages tied to chairs) count toward the total. 
Fake and irregular rescues don't count.

Segment     | Hostages | Officers | Running total |
------------+----------+----------+---------------+
Jungle base |     4    |     2    |       6       |
Ship        |     1    |     1    |       9*      |
Minefield   |     1    |     0    |      10       |
Train       |     1    |     1    |      12       |
Final areas |     8    |     4    |      24       |

* After completing the ship mission, the total is set to 9, no matter where it 
was before.

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3. STEALTH
Being spotted by guards or cameras sets off alarms, but so do certain weapons.

The following weapons are stealthy. They do not set off alarms:
FIST, KNIFE, HANDGUN + SILENCER, MACHINE GUN + SILENCER, CLAYMOR MINE, FLARE

The other weapons are not stealthy and do set off alarms:
HANDGUN, MACHINE GUN, SHOTGUN, MISSILE, GRENADE, MINE, EXPLOSIVE

The SILENCER is automatically used once acquired.

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4. ALARMS
  Once the alarm is set off, any guards on screen are alerted and more attack 
from off screen. In the last part of the game, the incoming guards are grenade 
throwers, who are stronger than the ordinary ones. The transciever is also 
disabled. Additionally, in the side-scrolling areas, bombs fall from bomb 
dispensers and the water is electrified.
  To deactivate the alarm, keep killing the guards that show up. You may use 
loud weapons for this, but the alarm will go off again if you fire after the 
last guard falls.

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5. ITEM DROPS
  It takes three hits to kill guards with PUNCH, but they may drop rations or 
ammo. Guards never drop anything if killed with the KNIFE or other weapons. The 
exception is the claymore users on the train, who always drop rations.

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6. ITEM CAPACITY
Dmg (Damage) is how many HP the weapon takes from a target.
Rec (Recovery) is how much time must pass before a target can be damaged again.
  (Time is expressed in frames, which are 1/60 second in the USA version.)
Pack is how many units are contained in a package.
The other columns show how many of each item Snake can carry at each rank.

Weapon/Item  | Dmg | Rec |Pack |   *   |  **   |  ***  | ****  | ***** | ******|
-------------+-----+-----+-----+-------+-------+-------+-------+-------+-------+
PUNCH        |  1  | 16  |     |       |       |       |       |       |       |
KNIFE        |  3  | 16  |     |       |       |       |       |       |       |
HANDGUN $    |  3  | 16  | 20  |  50   |  100  |  150  |  200  |  250  |  300  |
MACHINE GUN $|  3  | 16  | 20  |  50   |  100  |  150  |  200  |  250  |  300  |
SHOTGUN $    |  6  | 16  |  5  |  10   |   15  |   20  |   30  |   40  |   45  |
MISSILE #    | 11  | 48  |  5  |  10   |   15  |   20  |   30  |   40  |   45  |
GRENADE      |  9  | 48  |  5  |  10   |   15  |   20  |   30  |   40  |   45  |
CLAYMOR MINE |  9  | 16  |  3  |   5   |   10  |   15  |   20  |   25  |   30  |
MINE #       |  9  | 32@ |  5  |  10   |   15  |   20  |   25  |   30  |   40  |
FLARE        |  0  |     |  3  |   5   |   10  |   15  |   20  |   30  |   40  |
EXPLOSIVE    | 14  | 32  |  5  |   5   |   15  |   20  |   25  |   30  |   40  |
-------------+-----+-----+-----+-------+-------+-------+-------+-------+-------+
FOOD         |           |  1  |   3   |    6  |    9  |   12  |   15  |   18  |
TRUTH GAS    |           |  1  |   2   |    3  |    4  |    5  |    6  |    7  |
ANTIDOTE     |           |  1  |   3   |    6  |    9  |   12  |   15  |   20  |
OXYGEN TANK  |           |  1  |   1   |    3  |    5  |    7  |    9  |   12  |

$ Ammunition for the HANDGUN, MACHINE GUN and SHOTGUN is all bundled in ammo 
boxes. Other weapons and equipment require their own pickups.

# The BACK PACK item doubles the carrying capacity of MISSILEs and MINEs.

@ The actual recovery time for MINEs seems to be zero.

Snake needs to hold 24 MINEs to finish the game. The lowest RANK for this to be 
possible is **** without the BACK PACK or *** with the BACK PACK. (Snake's RANK 
is set to *** after the ship mission.)

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7. ENEMIES AND BOSSES
HP is the amount of life the boss begins with. You can't see this without 
  watching the memory of the game.
Damage lists how many bars of LIFE the boss takes off of Snake with each shot or
  body contact. The amount varies; the listed values are the upper limits. 
  Damage is reduced by equipping the ARMOR VEST item.
Weapons with a + work, those with a - don't work, and those with a . are 
  unavailable. The damage of each weapon is in the table above.

                    |     |   Damage   |                Weapons
Enemy/Boss          |  HP | Body  Shot | PNC KNF HGN MGN SGN MSL GRN CLY MIN EXP
--------------------+-----+------------+----------------------------------------
Guards              |   3 |    1    3  |  +   +   +   +   +   +   +   +   +   +
Door-blocker boxes  |  84 |    1   n/a |  +   +   -   -   -   -   -   -   -   +
Manhole cover boxes |   4 |   n/a  n/a |  -   -   -   -   -   +   +   -   .   +
Manhole guards      |  12 |    1    4  |  +   +   +   +   .   +   +   +   .   +
Underwater grate    |   4 |   n/a  n/a |  .   -   .   .   .   .   .   .   .   +
Floating detector   |  12 |    1   n/a |  .   -   +   .   .   .   .   .   .   +
Claymore users      |  18 |    1    5  |  -   -   +   +   .   +   +   +   .   +
Breakable walls     |   4 |   n/a  n/a |  -   -   -   -   -   -   -   -   -   +
Kamikaze guards     |   6 | death  n/a |  -   -   +   +   +   +   +   +   +   +
Grenade guards      |   6 |    1    5  |  +   +   +   +   +   +   +   +   +   +
Missile statues     |  24 |    1    5  |  -   -   +   +   +   +   +   +   +   +
Mini-metal gears    |  32 |    1    3  |  -   -   +   +   +   +   +   +   +   +
--------------------+-----+------------+----------------------------------------
Cyber-linebackers x5|  40 |    2   n/a |  -   -   +   +   .   .   +   .   .   +
Grenade tossers x3  |  52 |    1*   4  |  -   -   +   +   .   .   +   +   .   +
Impostor            |  96 |    6    5  |  -   -   +   +   .   +   +   +   .   +
Tank                | 162 | death death|  -   -   -   -   -   -   -   -   +   -
Big Boss I          |  96 |    1    3  |  -   -   +   +   +   +   +   +   +   +
Big Boss II         | 216 |   10    7  |  -   -   -   -   -   -   -   -   +** -
Metal Gear 2        | 144 |   n/a  n/a |  -   -   -   -   -   +   -   -   -   -

*  Falling into the pits causes instant death.
** Big Boss II must be lured away at least one room in order to take damage.

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8. MEMORY ADDRESSES
  You can keep track of these with a memory watcher in your emulator or use them
to make patch codes. All values for ammo and item supplies are already in 
decimal, so don't convert them from hex.

Address | Value                                  |
--------+----------------------------------------+
005b    | Alert status                           |
005c    | Number of guards left till alarm dies  |
0060-1  | Available/unlocked weapons*            |
006e    | Hostages rescued/Officers interrogated |
006f    | Rank                                   |
0070    | Snake's life                           |
0077    | Snake's invulnerability time           |
0088-a  | Available/unlocked equipment*          |
046e    | Snake's Y position                     |
046f    | EXPLOSIVE's Y position                 |
0484    | Snake's X position                     |
0485    | EXPLOSIVE's X position                 |
0470-3  | Snake's bullet's Y position            |
047a-e  | Enemy/boss Y position                  |
0486-9  | Snake's bullet's X position            |
0490-4  | Enemy/boss X position                  |
0590    | Time till cable car arrives            |
0574    | Time till EXPLOSIVE blows up           |
05cd-d1 | Enemy/boss life                        |
05d2-6  | Enemy/boss facing direction            |
05d7-b  | Enemy/boss invulnerability time        |
06c0-1  | HANDGUN ammo                           |
06c2-3  | MACHINE GUN ammo                       |
06c4    | SHOTGUN ammo                           |
06c5    | FLARE ammo                             |
06c6    | GRENADE ammo                           |
06c7    | MINE ammo                              |
06c8    | MISSILE ammo                           |
06c9    | EXPLOSIVE ammo                         |
06ca    | CLAYMOR MINE ammo                      |
06cb    | TRUTH GAS supply                       |
06cc    | ANTIDOTE supply                        |
06cd    | FOOD supply                            |
06ce    | OXYGEN TANK supply                     |

* Add the following values to the specified addresses to set which items are in 
inventory. You still need ammo for weapons and supplies for consumable items.

value | 0x0060      | 0x0061      | 0x0088      | 0x0089      | 0x008a      |
------+-------------+-------------+-------------+-------------+-------------+
0x01  | HANDGUN     | EXPLOSIVE   | CARD1       | SMOKE BOMB  | BATTERY     |
0x02  | MACHINE GUN | CLAYMOR MINE| CARD2       | HIDDEN MIKE | POWER ARMOR |
0x04  | SHOTGUN     |             | CARD3       | DETECT MINES| X-RAY LENS  |
0x08  | SILENCER    |             | CARD4       | BOOTS       | ANTENNA     |
0x10  | FLARE       |             | CARD5       | ARMOR VEST  | TRUTH GAS   |
0x20  | GRENADE     |             | CARD6       | NIGHT SITE  | ANTIDOTE    |
0x40  | MINE        |             | CARD7       | OPTIC LENS  | FOOD        |
0x80  | MISSILE     |             | CARD8       | BACK PACK   | OXYGEN TANK |

Example:
If the value at 0060 is c3, you have HANDGUN, MACHINE GUN, MINE and MISSILE.
0xc3 = 0x01 + 0x02 + 0x40 + 0x80

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9. BONUS
  See my tool-assisted speedrun of this game here:
  
http://tasvideos.org/2045S.html

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CLOSING
  This document is my own work. Any questions, comments, corrections or 
complaints should be addressed to the address below, with clear indication in 
the subject line that the email is concerning this FAQ.