Extending the demo: The House of the Dead
Exploring more of the prototype demo from HOTD Taikenban
In this edition:
The House of the Dead Taikenban normally lets you play part of the first chapter.
But we can patch the demo to let us play more of it.
The demo is based on a prototype from 2 months before the final game, so you’ll notice some differences when playing.
Get a patch to play the rest of the first stage at SegaXtreme! Here’s a video showing side-by-side differences with the final version (left: prototype demo, right: final)
Introduction
The House of the Dead Taikenban - Burning Rangers Taikenban Double Pack, as its name suggests, is a bundle with two demo discs: one for Burning Rangers and one for The House of the Dead. The BR one is super interesting, so what about the HOTD one?
Based on the file dates, the demo is from a prototype build of the game. It’s from 1997-12-29, whereas the final is from 1998-02-25. You get two minutes to play it (though the countdown pauses during cutscenes), which lets you get through part of the first stage. Is there any more on the disc?
Answer: yes! It’s a small demo - only 20 MB - but it’s got the whole first stage on it. There are some differences with the final version - it looks like Tantalus was able to take care of some unfinished bits in the last weeks of development.
Patching details
By comparing memory snapshots with the game paused versus unpaused, I found that the byte at 060ab86c changes from 00 to 01 when you press Start.
And what checks that address? The function at 06016564, which does some suggestive subtraction if it’s non-zero.
All we need to do is nullify that subtraction. The patch is:
060165ec 0009That keeps the demo countdown timer permanently at 2 minutes, and lets us play the whole first stage.
…if we’re good enough to get through it, that is. I’m not! So I decided to give myself infinite health by nullifying the result of another subtraction operation: the one that executes if you get hit by an enemy.
The Action Replay code is:
160ab676 0009Now when we’re attacked our health won’t go down.
The last thing to do is to restore access to the Options screen. You can look at it, but can’t modify any of its items in the demo. It seems that this is because the menu cursor (stored at 060b3977) is being forced to the value 0a (for Exit). We can restore the functionality of the down button with these patches:
25c789c8 0009
25c788b0 0009That lets us edit the various menu items. The demo doesn’t respect the values for Life and Continues, alas.
Demo / prototype differences
So what’s different between this build and the final one? You can see several things without hacks: the title and options screens have been totally reworked:
The chapter title cards have been redesigned, too:
If you keep going past the prototype demo’s normal end, you’ll see more unfinished things. It seems slow to load textures - a lot of times you’ll see corrupt graphics for a moment. And some textures are missing entirely.
Some enemies look different:
The Chariot boss doesn’t have the introduction card:
There are lots of other things that don’t match. Tell me if you spot anything else that’s notable! See the video above for some side-by-side comparisons.
Outro
For more on demo discs with hidden extras, see my user page on Hidden Palace.
If you know of any other demos with potentially interesting extras (not just Saturn), send me a note. This one was suggested by James!
One of these days I'm going to install Ghidra.