Difference between revisions of "Bugs: NES"

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The following is a list of all known programming errors and technical issues.
 
The following is a list of all known programming errors and technical issues.
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==Arm Collision Detection==
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{| style="margin-left:20px;" border="1" align="right" cellspacing="0"
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|align="center"|
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[[Image:NES-Error-ArmCollisionDetection.png]]
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|}
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If you swing on your arm just below where a soldier is walking collision detection will occur between your arm and the soldier even when they're not touching. This happens because the collision mask used on the arm is taller than the arm actually is.
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Type: Programming oversight<br>
 +
Versions: All<br clear="all" />
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 +
 +
==Broken Arm==
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{| style="margin-left:20px;" border="1" align="right" cellspacing="0"
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|align="center"|
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[[Image:NES-Error-BrokenArm.png]]
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|}
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By using the Walk In Barrel bug, it's possible to sever your bionic arm. First, get stuck in a barrel. Then throw your arm to a nearby ledge. Press left or right and the game will force Radd out of the barrel, but it will keep the arm connection, thus severing the arm. This occurs because the forced movement of Radd doesn't cause his arm to lose grip although it should.
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Type: Programming oversight<br>
 +
Versions: All<br clear="all" />
 +
  
 
==Enemies Don't Freeze==
 
==Enemies Don't Freeze==
 
When you destroy the [[main system]] at the end of each area the game freezes [[Radd]] for a nice dramatic effect. Unfortunately, the game does not freeze the enemies, nor does it make you invincible. So, it's quite possible to destroy the main system, and then take a bullet in the head because you can't duck anymore.
 
When you destroy the [[main system]] at the end of each area the game freezes [[Radd]] for a nice dramatic effect. Unfortunately, the game does not freeze the enemies, nor does it make you invincible. So, it's quite possible to destroy the main system, and then take a bullet in the head because you can't duck anymore.
  
<br clear="all" />
+
Type: Programming oversight<br>
 +
Versions: ?<br clear="all" />
 +
 
 +
 
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==Enemies Walk On Spikes==
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{| style="margin-left:20px;" border="1" align="right" cellspacing="0"
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|align="center"|
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[[Image:NES-Error-EnemiesWalkOnSpikes.png]]
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|}
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Only Radd has collision detection for spikes and springs which means that even though they should be affected by them, enemy soldiers are not.
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Type: Programming oversight<br>
 +
Versions: All<br clear="all" />
  
 
==Flare Bullet==
 
==Flare Bullet==
Line 13: Line 48:
 
The game treats the [[flare bomb]] as a bullet. Its flag, location, and velocity are all stored in the same memory that is reserved for a player's bullets. Not only does this mean that firing a [[weapons|weapon]] with three bullets will make the flare immediately disappear, but also the flare has collision detection with [[enemies]]. However, a flare doesn't have a damage flag, so if you walk under an enemy and shoot a flare, you will cause an error in the game and reset the area.
 
The game treats the [[flare bomb]] as a bullet. Its flag, location, and velocity are all stored in the same memory that is reserved for a player's bullets. Not only does this mean that firing a [[weapons|weapon]] with three bullets will make the flare immediately disappear, but also the flare has collision detection with [[enemies]]. However, a flare doesn't have a damage flag, so if you walk under an enemy and shoot a flare, you will cause an error in the game and reset the area.
  
This error only occurs in the North American and European versions of the game.
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Type: Programming error<br>
 
+
Versions: North American, European<br clear="all" />
<br clear="all" />
 
  
 
==Flare Offset==
 
==Flare Offset==
Line 24: Line 58:
 
If you are ducking when using the flare bomb the flare won't shoot from your body, but from your gun.
 
If you are ducking when using the flare bomb the flare won't shoot from your body, but from your gun.
  
This error occurs in all versions of Bionic Commando.
+
Type: Programing oversight<br>
 
+
Versions: All<br clear="all" />
<br clear="all" />
 
  
 
==Friendly Fire==
 
==Friendly Fire==
Line 35: Line 68:
 
At the end of a [[meet with enemy]] sequence an allied soldier is waiting in front of the helicopter waving you on in. Even though he is an ally if you touch him you take damage. This bug exists because no special code was written for non-hostile sprites in the combat sequence. Everything that isn't Radd uses the code for an enemy.
 
At the end of a [[meet with enemy]] sequence an allied soldier is waiting in front of the helicopter waving you on in. Even though he is an ally if you touch him you take damage. This bug exists because no special code was written for non-hostile sprites in the combat sequence. Everything that isn't Radd uses the code for an enemy.
  
This bug occurs in the Japanese version of the game.
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Type: Programming oversight<br>
 
+
Version: Japanese<br clear="all" />
<br clear="all" />
 
  
  
Line 45: Line 77:
 
[[Image:NES-Error-Hovering.png]]
 
[[Image:NES-Error-Hovering.png]]
 
|}
 
|}
Due to the way the Radd's sprite changes when he throws his [[bionic arm]] out, it's possible to make him look like he's hovering in mid air. This is an issue with how collision detection works with the player's sprite and the background. It's not a technical bug, more like an artistic mistake.
+
Due to the way the Radd's sprite changes when he throws his [[bionic arm]] out, it's possible to make him look like he's hovering in mid air. This is an issue with how collision detection works with the player's sprite and the background.
  
This error occurs in all versions of Bionic Commando.
+
Type: Graphical oversight<br>
 +
Versions: All<br clear="all" />
  
<br clear="all" />
 
  
 
==Sprite Mirroring==
 
==Sprite Mirroring==
In order to save space many early videogames mirror their sprite graphics to depict a change in direction. This creates issues for human sprites because they're constantly switching their dominant hand when they're seen holding something. For example, Radd's bionic arm and gun swap hands each time he changes direction. The same is true for all enemy and allied soldiers that hold weapons. This is more of a technical limitation than a programming error.
+
In order to save space many early videogames mirror their sprite graphics to depict a change in direction. This creates issues for human sprites because they're constantly switching their dominant hand when they're seen holding something. For example, Radd's bionic arm and gun swap hands each time he changes direction. The same is true for all enemy and allied soldiers that hold weapons.
 +
 
 +
Type: Technical limitation<br>
 +
Versions: All<br clear="all" />
 +
 
 +
 
 +
==Standing On Spikes==
 +
{| style="margin-left:20px;" border="1" align="right" cellspacing="0"
 +
|align="center"|
 +
[[Image:NES-Error-StandingOnSpikes.png]]
 +
|}
 +
With the proper timing it's possible to create a situation that's physically impossible. If you throw an angled arm just in time to save you from hitting spikes it's possible to not take any damage from them, but still be walking on them. This is a bug in the order of collision detection. Once the arm successfully grabs, no more checks are made to see if you're standing on spikes.
  
This error occurs in all versions of Bionic Commando.
+
Type: Programming oversight<br>
 +
Versions: All<br clear="all" />
 +
 
 +
 
 +
==Standing On Springs==
 +
{| style="margin-left:20px;" border="1" align="right" cellspacing="0"
 +
|align="center"|
 +
[[Image:NES-Error-StandingOnSprings.png]]
 +
|}
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For the same reason you can stand on spikes, it's possible to stand on springs that would normally bounce you up.
 +
 
 +
Type: Programming oversight<br>
 +
Versions: All<br clear="all" />
 +
 
 +
 
 +
==Walk In Barrels==
 +
{| style="margin-left:20px;" border="1" align="right" cellspacing="0"
 +
|align="center"|
 +
[[Image:NES-Error-WalkInBarrel.png]]
 +
|}
 +
Unlike walls, barrels don't knock you back when you swing into them. This makes it possible to grab above a barrel, swing into it, and then press down to drop inside of it.  
  
<br clear="all" />
+
Type: Programming oversight<br>
 +
Versions: All<br clear="all" />

Revision as of 11:21, 21 November 2007

The following is a list of all known programming errors and technical issues.


Arm Collision Detection

NES-Error-ArmCollisionDetection.png

If you swing on your arm just below where a soldier is walking collision detection will occur between your arm and the soldier even when they're not touching. This happens because the collision mask used on the arm is taller than the arm actually is.

Type: Programming oversight
Versions: All


Broken Arm

NES-Error-BrokenArm.png

By using the Walk In Barrel bug, it's possible to sever your bionic arm. First, get stuck in a barrel. Then throw your arm to a nearby ledge. Press left or right and the game will force Radd out of the barrel, but it will keep the arm connection, thus severing the arm. This occurs because the forced movement of Radd doesn't cause his arm to lose grip although it should.

Type: Programming oversight
Versions: All


Enemies Don't Freeze

When you destroy the main system at the end of each area the game freezes Radd for a nice dramatic effect. Unfortunately, the game does not freeze the enemies, nor does it make you invincible. So, it's quite possible to destroy the main system, and then take a bullet in the head because you can't duck anymore.

Type: Programming oversight
Versions: ?


Enemies Walk On Spikes

NES-Error-EnemiesWalkOnSpikes.png

Only Radd has collision detection for spikes and springs which means that even though they should be affected by them, enemy soldiers are not.

Type: Programming oversight
Versions: All

Flare Bullet

NES-Error-FlareBullet.png

The game treats the flare bomb as a bullet. Its flag, location, and velocity are all stored in the same memory that is reserved for a player's bullets. Not only does this mean that firing a weapon with three bullets will make the flare immediately disappear, but also the flare has collision detection with enemies. However, a flare doesn't have a damage flag, so if you walk under an enemy and shoot a flare, you will cause an error in the game and reset the area.

Type: Programming error
Versions: North American, European

Flare Offset

NES-Error-FlareOffset.png

If you are ducking when using the flare bomb the flare won't shoot from your body, but from your gun.

Type: Programing oversight
Versions: All

Friendly Fire

NES-Error-FriendlyFire.png

At the end of a meet with enemy sequence an allied soldier is waiting in front of the helicopter waving you on in. Even though he is an ally if you touch him you take damage. This bug exists because no special code was written for non-hostile sprites in the combat sequence. Everything that isn't Radd uses the code for an enemy.

Type: Programming oversight
Version: Japanese


Hovering

NES-Error-Hovering.png

Due to the way the Radd's sprite changes when he throws his bionic arm out, it's possible to make him look like he's hovering in mid air. This is an issue with how collision detection works with the player's sprite and the background.

Type: Graphical oversight
Versions: All


Sprite Mirroring

In order to save space many early videogames mirror their sprite graphics to depict a change in direction. This creates issues for human sprites because they're constantly switching their dominant hand when they're seen holding something. For example, Radd's bionic arm and gun swap hands each time he changes direction. The same is true for all enemy and allied soldiers that hold weapons.

Type: Technical limitation
Versions: All


Standing On Spikes

NES-Error-StandingOnSpikes.png

With the proper timing it's possible to create a situation that's physically impossible. If you throw an angled arm just in time to save you from hitting spikes it's possible to not take any damage from them, but still be walking on them. This is a bug in the order of collision detection. Once the arm successfully grabs, no more checks are made to see if you're standing on spikes.

Type: Programming oversight
Versions: All


Standing On Springs

NES-Error-StandingOnSprings.png

For the same reason you can stand on spikes, it's possible to stand on springs that would normally bounce you up.

Type: Programming oversight
Versions: All


Walk In Barrels

NES-Error-WalkInBarrel.png

Unlike walls, barrels don't knock you back when you swing into them. This makes it possible to grab above a barrel, swing into it, and then press down to drop inside of it.

Type: Programming oversight
Versions: All