Unused Code

This is a sub-page of Castlevania (Nintendo 64).

Debugging Features#

Crash Screen#

Code exists for a crash screen, which displays information such as registers and stack, when the game crashes. This code is disabled by default, as the thread associated with the crash screen is never created nor started.
By manually creating and starting the thread, the game will print the message => faultproc - waiting for message.... If the game crashes, the string => faultproc - got a fault message... is printed, and the contents of the registers and the stack (as well as the cause of the crash) will be printed to a debug console.

Use this code to make the crash screen work. It initializes the crash screen thread, which replaces a useless branch in the audio initialization function with a call to the crash thread init and start function at 0x80019b48 (have the cheat enabled before booting the game, or do a hard reset with the code enabled for the effects to take place).

Then, make the game crash and the contents should be printed to the debugging console (on emulator, this script works for simulating a debugging console). The game can be crashed in various ways. An easy method is by setting $ra in a "jr ra" assembly instruction to 0. For example, set a breakpoint at 0x80015464 (USA v1.0) and set the contents of $ra to 0, then continue the game and the game will crash.

Functions#

The functions associated with this crash screen start in the following RAM addresses. These addresses are for the USA v1.0 version of the game:

Explanation#

• Fault in thread X. X = thread ID (5 = Main thread)
• epc: Address of instruction that caused exception
• cause: Type of exception and pending interrupt bits
• sr: Interrupt mask, enable bits, and status when exception occurred
• badvaddr: Memory address where exception occurred
• at, v0-v1, a0-a3, t0-t7, s0-s8, t8-t9, gp, sp, ra: Registers
• fpcsr: FPU control and status register
• d0-d30: Floating point-registers

Process Meter#

There's unused code for handling and rendering a process meter, which can be found in other Konami games for the N64, such as Mystical Ninja Starring Goemon (Nintendo 64).

Each bar is supposed to represent a timer value that would be updated regularly, perhaps the time some specific threads would have taken (like with Super Mario 64). If a bar exceeds a certain limit, it either turn red, or the meter would be subdivided into more pieces (the game renders 3 divisions by default). Unfortunately, no code calls the update function for the process meter, so it's not possible to tell precisely where it would have been used.

Only two bars are rendered. However, the update function references 4 timer values (2 are for the green and blue bars, so it's possible the other 2 were for other 2 bars). In addition, prerelease footage show that there were originally 4 bars.

Use this code to render the process meter. Note that it will only render the meter, but won't update the bars, so said bars will appear static. Lines 3-4 and 5-6 change the size of the green and blue bar respectively. They're float values, so for example, in the code below, the green bar size value was set to 0x42000000 = 32, and the blue bar size was set to 0x41700000 = 15. The last line changes the number of divisions to 4.

Below are the functions associated with the process meter. These addresses are for the USA v1.0 version of the game:

And below is the global / static data associated with the process meter. These addresses are for the USA v1.0 version of the game:

Stage Select#

An unused game state exists, a simple stage select menu. It can be enabled with the use of the below code and pressing L + Z at any time in-game.

The menu is stylized similarly to the rest of the menus from the game. Every time the player access a map, the event flags, items, subweapons, money, etc are all wiped.

It can access 8 locations in the game:

These are all locations that Reindhart can access. The only exception is "VS Actriese", as he can't battle her in the final game. However, prerelease footage shows Reindhart fighting against her.

An article from IGN covering the appearance of the game at TGS 1998 states that "several areas of the game are now playable (selected via a startup menu), including a forest scene, the castle entrance, and a harrowing battle against Death himself". Said startup menu could be this stage select, as it has options for warping to the forest and to a battle against Death.

Unseen Title Demo Debugging Text#

Whenever the player enters the Title Demo (with Reindhart playing on the tunnel), the following text is printed on the debugging console. Note that the actual text doesn't have newlines. They've been put here for readability.

wait cont = 1
wait cont = 2
wait cont = 3
wait cont = 4
wait cont = 5
wait cont = 6
wait cont = 7
wait cont = 8
wait cont = 9
wait cont = 10
wait cont = 11
wait cont = 12

cont stands for controller. What's being printed is field 0x64 of the struct that handles the title demo. This variable represents the delay time (in frames) from the demo's start until the game starts reading the playback controller data. In this case, there were 12 frames of delay.

Good Ending Castle Map Pieces - Unused Sinking Feature#

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The destroyed castle pieces seen in both good endings (which appear static in the game) have an unused feature where they would sink to the ground. These pieces also appear in Carrie's good ending, but they can't be seen without hacks. They don't make any sound whe falling off.

These are not the same castle pieces used in the "Castle Destruction" cutscene that plays before the ending cutscenes, which are handled by completely different actors.

Unused Camera Mode#

The code that handles the player camera defines two modes: Normal / Action view and Boss Battle view. However, a third one exists, which has an empty function associated to it (0x8006bcf4), therefore it does not move the camera at all when activated.

Unused Gardener Variables#

The Gardener's enemy code saves the first variable from the map's actor data, as well as the current time of the day (day, night, dawn / dusk), but they're never read.