C64 Dungeon Trap Glitch

Discussions and help for Bard's Tale II: The Destiny Knight
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Darendor
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C64 Dungeon Trap Glitch

Post by Darendor »

It seems Saxon1974 and I have determined that our copies of BTII for the C64 have a glitch in them - dungeon traps do not affect the party at all, regardless of experience levels.


So, I wanted to ask anyone running the C64 version of BTII to test this theory out for themselves and report their findings here.

Thanks.
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Saxon1974
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Post by Saxon1974 »

In addition, I also tried this on an Apple II emulator and the same issue occurs there.

See the other thread in the Developers Heaven section. (Not sure how to link a thread with the way this forum doesn't display a URL).

So, seems like original 2 versions of the game have this issue when emulated.
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ZeroZero
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Post by ZeroZero »

I have made a zip with decoated D64 images, i.e. with the files visible. They are still (supposed) xor'ed by $EA. But files could be de-xored and then the TRAP event be found (should be very similar to the one from BT1 where it is within file NM1D). In there should be a call to the damage routine, if you dissassemble that routine, you likely find the bug.
Can mail you that zip.
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Saxon1974
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Post by Saxon1974 »

ZeroZero wrote:I have made a zip with decoated D64 images, i.e. with the files visible. They are still (supposed) xor'ed by $EA. But files could be de-xored and then the TRAP event be found (should be very similar to the one from BT1 where it is within file NM1D). In there should be a call to the damage routine, if you dissassemble that routine, you likely find the bug.
Can mail you that zip.
Hmm, I would love to take a look but I dont know anything about how to "dissassembe" D64 images. I dont know what decoated or xor'ed means either (Im guessing encoded and or copy protected?).

I doubt im the right guy to do this debugging, sounds like you and twoflower have been looking into it in the developer section.

I would be happy to assist with testing in any way that would be needed though.

Thanks for looking into this bug.
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Saxon1974
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Post by Saxon1974 »

Well, it appears we have confirmation that the DISC versions work normally.

http://rpgcodex.net/phpBB/viewtopic.php?t=28706
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Darendor
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Post by Darendor »

well, i tried loading BT2 yesterday and the traps works fine on the Disc version and the tape version on level 3 of the starter dungeon, so i guess it must something about the emulation.
I don't understand why EVERYTHING about the game would translate to the emulator fine except for the trap bug. That doesn't make sense to me.

I think that all the versions of the disk ROMS on the Internet were sourced from a defective copy. :?


Maybe you could ask this guy to transfer his disk to ROM images and then try playing from them.
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Saxon1974
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Post by Saxon1974 »

Darendor wrote:
well, i tried loading BT2 yesterday and the traps works fine on the Disc version and the tape version on level 3 of the starter dungeon, so i guess it must something about the emulation.
I don't understand why EVERYTHING about the game would translate to the emulator fine except for the trap bug. That doesn't make sense to me.

I think that all the versions of the disk ROMS on the Internet were sourced from a defective copy. :?


Maybe you could ask this guy to transfer his disk to ROM images and then try playing from them.
A good suggestion however I still dont see how the Apple II version would also be bad.

I asked the guy if he would try doing this....

Here

http://rpgcodex.net/phpBB/viewtopic.php ... 6&start=25
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ZeroZero
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Post by ZeroZero »

Just my two cents:

how big is the chance, that of all possible errors, exactly the trap event got destroyed on the disk, and that w/o defecting the game fully?

On the C64 the files are hidden plus encrypted, so a hack also is very unlikely.

It is unlikely that all versions root back to the same source set of disks also.

If the error occurs on Apple II also, then not only all C64 emulators are defective, but also some Apple II emulators, PLUS the same random error happened to the Apple II version....

I rather think, that the C64 and Apple II versions really have a bug. Maybe that had been corrected in a later new issue. Or it is tape version versus disk version, German version vs French or English version, NTSC vs PAL version etc etc etc
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Darendor
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Post by Darendor »

I suspect programmer error was the problem and as such all C64/Apple II versions have the same glitch.
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Saxon1974
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Post by Saxon1974 »

Ok the user has agree to extract to Roms and test his disc version that way but he does not know how.

Can you provide instructions on how he can create roms from his discs? He would just need to have a way to save the floppy .d64 (C64 image files) to his windows PC.

Suggestions?
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ZeroZero
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Post by ZeroZero »

*Sigh* This requires a special cable between original Commodore hardware and the PC and a (freeware) program like e.g. StarCommander.
Please see Peter Schepers homepage for the best cable choice...

E D I T

The *sigh* was only meant, because that requires more work from that user than he/she likely is willing to do. Plus the money for a cable.

E D I T 2
If I say it, I better provide the link also... sorry!
http://ist.uwaterloo.ca/~schepers/cables.html
 
 
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Saxon1974
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Post by Saxon1974 »

ZeroZero wrote:*Sigh* This requires a special cable between original Commodore hardware and the PC and a (freeware) program like e.g. StarCommander.
Please see Peter Schepers homepage for the best cable choice...

E D I T

The *sigh* was only meant, because that requires more work from that user than he/she likely is willing to do. Plus the money for a cable.

E D I T 2
If I say it, I better provide the link also... sorry!
http://ist.uwaterloo.ca/~schepers/cables.html
 
 
Dang, yea I understand your sigh, very unlikely he will be willing but I can ask. If its not too much I could chip in some for the cost of the cable.
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ZeroZero
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Post by ZeroZero »

Peter Schepers offers free soldering and cabling plans plus list of parts needed. Also he offers to sell you finished cable, a cable will be up to US$ 20.
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Twoflower
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Post by Twoflower »

Actually, to backup a Pirateslayer protected disk (read: original BT2) you need to MNIB the disk (http://markus.brenner.de/mnib/). What fails in the above reasoning is that this have been done before concerning this original - several times in fact.

I just fail to see what the use of backing up the above mentioned disks.
/Twoflower
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Darendor
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Post by Darendor »

Twoflower wrote:Actually, to backup a Pirateslayer protected disk (read: original BT2) you need to MNIB the disk (http://markus.brenner.de/mnib/). What fails in the above reasoning is that this have been done before concerning this original - several times in fact.

I just fail to see what the use of backing up the above mentioned disks.
To make sure it's a defect with the actual code? :?
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