Differences Between SNES Version of Dungeon Master and More Standard Versions of the Game.

[Paul Stevens]

See BUG0_12 in ReDMCSB

My GOD, man! I am looking at 'Bugs and Changes' for the first time.
How did you do this? You must be Obsessive-Compulsive squared!

Is this available on the internet with a URL? If not, may I have
permission to post it? Along with all of ReDMCSB/DOC.
I'm very sorry that I am not up-to-date with this work you have done.
How did I miss this? I am stunned.

[jayrshaw]

This is a known bug that creates cloned items. This bug is present in all versions of the game and was never fixed despite obvious attempts in the source code. The developers were well aware of cloned items and thought it was caused by chest management issues, but failed to identify the actual cause which lies in the code to steal items.
It occurs when a Giggler steals an item from your inventory that was previously stored in a chest with other items.
See BUG0_12 in ReDMCSB (in BugsAndChanges.htm and also in source code in GROUP.C) for details.

Thanks for the information, Christophe (and you too, Paul)! Your explanation makes sense because my characters were probably carrying screamer slices in their inventory that were previously stored in treasure chests (I had been replacing the screamer slices in chests with drumsticks and/or water flasks as I acquired them). My characters also might have been carrying water flasks in their inventory that were previously stored in chests; I believe it was quite some time after I began storing excess water flasks in treasure chests when I discovered that you could carry a water flask in a character's water pouch; at that time, I might have moved some water flasks from treasure chests to characters' water pouches. Now that you mention it, every time the bug cropped up, the giggler would drop at least one screamer slice and/or water flask. I'll have to be extra careful with gigglers from now on (hopefully I won't run into too many now that I'm close to the end of the game)!


--Jay

[Paul Stevens]

I'll have to be extra careful with gigglers from now on

Once an item is 'cloned' it will be very difficult to avoid the disastrous effects.
A single such item easily causes problems with any other items that come near it.
This includes monsters, clouds, missiles, and even dungeon mechanics.

Someone said the saved game format is the same as the Atari and PC versions.
If so, perhaps CSBuild could read your saved game and determine how bad the
problem is. If you have old saves, we might find one that is intact.

[jayrshaw]

Once an item is 'cloned' it will be very difficult to avoid the disastrous effects.
A single such item easily causes problems with any other items that come near it.
This includes monsters, clouds, missiles, and even dungeon mechanics.

Someone said the saved game format is the same as the Atari and PC versions.
If so, perhaps CSBuild could read your saved game and determine how bad the
problem is. If you have old saves, we might find one that is intact.

Thanks, Paul! Fortunately, after discovering the bug, I kept resetting the game and killing the giggler until I was able to verify that it wasn't carrying any cloned items. The giggler that I killed before proceeding with the game was only carrying a Jewel Symal that one of my characters had been wearing. Conversely, the gigglers I killed that triggered the bug generally dropped quite a few items (generally including one or more screamer slices, one or more water flasks, an axe, a morningstar, a Stormring, a Staff of Manar, and/or a Yew Staff). Also, each time I triggered the bug, there was a strange orb floating in the air in the vicinity of where the giggler had been. The orb was definitely not there on the occasion that I actually proceeded with the game.


--Jay

[Paul Stevens]

Fortunately, ..............

Hopefully you can avoid problems. I wish you luck.

[jayrshaw]

Thanks, Paul - I'll post again if I encounter any issues.


--Jay

[ChristopheF]

To avoid the bug, there a (tedious) workaround:
- Start by putting all items you are carrying on the floor. Then grab all items again and place them back in your inventory. This 'cleans' all items.
- After that initial cleanup, each time you take an item out of a chest, make sure to put it on the dungeon floor before grabbing it again and placing it in your inventory. If you move an item from a chest into your inventory directly, you may trigger the bug if that item is later stolen.

As Paul wrote, if you already have cloned items in your saved game, the risk of issues will always remain.

FTL included a fix in CSB for Atari 2.1 to clean up cloned items: when a saved game is loaded, it is scanned for clones and clones are removed. This function however is not found in any other version of the DM or CSB.

@Paul, the 'Bugs and Changes' file has always been part of the ReDMCSB archive since its initial release in January 2014.
It was not available online (apart from inside the zip file), but you can do whatever you want with it.
I have worked a lot since then and the next release of ReDMCSB will contain the source code of all programs of all versions of DM/CSB except the SNES versions. I am slowly cleaning up the source code before posting anything online (it is quite a big mess right now!), hopefully by the end of this year.
There will also be a few additional bugs listed in the document.

[ChristopheF]

How did you do this?

Well, documenting all the bugs and differences between versions was one of my goals with ReDMCSB, along with a completed understanding of the binary items (558 to 562), and a complete understanding of the copy protection scheme.
Once I had the source code for all Atari ST versions merged in a single source with conditional compilation directives, I studied each difference to understand why they made the change. I discovered a lot of bugs in that way, and tested many of them in the game, with the help of Steem Boiler Room (a nice and powerful debugger in the Steem Atari ST emulator), and creating custom dungeons to test various conditions. Many hours of work!

[jayrshaw]

Thanks for the advice, Christophe! By the way, I just looked at your ReDMCSB list of bugs and changes, and I have to agree with Paul - that is huge and really amazing! Thank you for doing all of that work!


--Jay

[Paul Stevens]

Many hours of work!

I'd wager the number is more intuitively expressed in units of months.

[jayrshaw]

I just completed Floor 6 of the dungeon and discovered a few differences between the SNES version of Dungeon Master and standard PC versions of the game. The layout of the portion of the dungeon immediately prior to the stairway at the end of the floor is a bit different in the SNES version of the game (in particular, the stone golem in the passage leading to the stairway can show up a bit earlier than you might expect). Also, in the SNES version of the game, there are two Winged Key locks on Floor 6 of the dungeon immediately prior to this stairway that provide a shortcut to the part of the floor where the Firestaff is located; in fact, if you use these passageways, you don't technically have to use the last Ra Key in order to access the Firestaff.

I don't know if this is normal, but in the SNES version of the game, the Winged Key does not disappear when you use it in a lock. As far as I can tell, there are a total of 3 Winged Key locks in the SNES version of Dungeon Master; the first two locks open the passageways on Floor 6 that I mentioned above, and the third lock opens a passageway to the beginning part of Floor 12 from the bottom of the stairway system that starts at the end of Floor 6. Also, if I am interpreting the SNES game data that Christophe provided to me correctly, there is apparently no Winged Key door on Floor 13 of the dungeon leading to the dragon's den in the SNES version of the game; instead, in the SNES version of the game, there appears to be an open door leading directly into the dragon's den immediately after you descend the stairway from Floor 12.


--Jay

[jayrshaw]

I've made a bit more progress in my game and discovered that the Winged Key does in fact disappear once you open the third Winged Key lock that is located on Floor 12 of the dungeon (I'm not sure if using the key in this particular lock makes the key disappear or if it simply disappears after you've opened all 3 Winged Key doors in the dungeon). I've also verified that once you have the incomplete Firestaff in your inventory, there will no longer be a wall blocking access to the section of Floor 12 where Chaos and his minions are lurking.

However, upon attempting to enter the section of Floor 12 with Chaos and his minions, I discovered that the first square you step on in this area transforms into a pit as soon as you step on it. As far as I can tell, there is no way to avoid this pit in the SNES version of the game (you can't use the rope to climb down the pit, either, since the pit doesn't actually open up until you step on the dungeon square where it is located). However, at the point in the game where you encounter the pit, you need to go to Floor 13 to fuse the Power Gem onto the Firestaff, anyway, so I guess it isn't too big a deal that you end up falling down into Floor 13 as soon as you access the main portion of Floor 12 of the dungeon.

The point of the dragon's den you end up in when you fall down the pit is just a couple of spaces away from where the dragon starts out, so I would recommend avoiding the pit until you are actually ready to take on the dragon (I wasn't ready to fight him yet, so I just reset my game after exploring the pit). Also, I would hazard a guess that this pit is basically a "point of no return" in the SNES version in the game because it blocks the only passage back up to earlier floors of the dungeon. Then again, the SNES game data Christophe provided to me seems to indicate that the pit activates only when you have the Firestaff in your inventory, so you might be able to get back to earlier floors by throwing the Firestaff across the pit, crossing the pit square without the Firestaff in your inventory, and then picking the Firestaff up again (I'll have to test this theory once I've gotten to that point of the dungeon).


--Jay

[jayrshaw]

Ok - I was finally able to complete the SNES version of Dungeon Master this afternoon. I discovered that you can avoid falling in the pit at the entry point to the main area of Floor 12 by throwing the Firestaff over the square where the pit opens (i.e., having the Firestaff in your inventory is apparently what triggers the pit opening). However, if you throw the Firestaff over the pit, it will end up falling into another pit a few squares ahead of you, so you will have to retrieve it from the middle of Floor 13 after you descend the stairway leading there.

At any rate, once you begin exploring Floor 13, you will soon discover that a sealed door is blocking the stairway leading back to Floor 12 of the dungeon (after taking a few steps forward from the stairway in either direction, you will trigger a floor plate that seals the door leading back to the stairway, and, likewise, if you enter the floor via a pit, you will trigger one of the floor plates if you head back toward the stairway). As I mentioned in an earlier post, you will also discover that the dragon is lurking very near the stairway you enter the floor from (he is also very near the square you fall on if you enter via the pit at the entry point to the main area of Floor 12).

However, this also means that the dragon is not guarding the Square Key and lock at the far side of Floor 13. As a result, I found it to be ridiculously easy to simply run past the dragon, grab the Square Key, use it in the doorway at the far side of the floor, fuse the Power Gem to the Firestaff, and run back across the floor to the stairway leading back to Floor 12 (using the Square Key in the lock leading to the Power Gem room also unseals the door blocking the way to the stairway back to Floor 12). I also tried killing the dragon and found that it was very easy to do so by freezing him with four green magical boxes, throwing four Ven (i.e., poison) bombs at him, and repeatedly casting the Poison Cloud spell on him until he died.

Unlike in other versions of Dungeon Master, in the SNES version of the game, throwing the completed Firestaff from the space where you seal it with the Power Gem through the Square Key door leading out of the room does not prevent the walls on Floor 12 of the dungeon leading back toward the Floor 11 stairway from being sealed off. In fact, in the SNES version of the game, these walls apparently become sealed at some point before you actually fuse the Power Gem to the Firestaff. To be on the safe side, I would assume that you are probably entering a "point of no return" as soon as you venture into the main part of Floor 12 of the dungeon where Chaos and his minions are lurking (and certainly once you trigger the floor plate on Floor 13 sealing the door leading to the stairway back to Floor 12); I tested this by descending to Floor 13 of the dungeon, doing nothing but retrieving the Square Key and opening the Square Key door, and then returning to Floor 12 of the dungeon (the way leading back to the Floor 11 stairway was already sealed by the time I had performed these actions).

Another difference between the SNES version of Dungeon Master and standard versions of the game is that one coin of any type will open the door on Floor 13 leading to the Altar of Vi in the SNES version of the game; as a result, you can simply pick up one of the many copper coins lying around the dragon's den and use it in the coin slot if you need to access the Altar. I don't know if this is the typical ending sequence or not, but in the SNES version of the game, the game's ending sequence shows maps of the various floors of the dungeon rotating in the background with the various creatures you encounter in the dungeon in the foreground (e.g., it might show a map of Floor 12 of the dungeon rotating in the background with Lord Chaos and a Demon in the foreground in the upper-left and lower-right corners of the screen).

Anyway, cheers to a great game, and thank you to everyone who provided me with advice as I was working at completing it!!


--Jay