Colossal Cave Adventure (Anubis Software)

Games for Spectrum, C64, Amstrad, Amiga, Apple ][ and the rest of the 8-bit and 16-bit platforms. Pleas for help, puzzles, bug reports etc.

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boldir
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Colossal Cave Adventure (Anubis Software)

#1 Post by boldir » Thu Mar 24, 2022 6:42 pm

Hi,
I've tried to solve another Colossal Cave Adventure (the one from Ross Harris, Anubis Software, 1985 - I wonder why this is not in the 'Related' list), but there is a problem with the PLOVER command in Room Y2 (loc. 26) and in the Small chamber with the emerald (loc. 58); it doesn't work at all. Does anybody know what the conditions mean?

7f83: PLOV _ Conditions:
7000: ZERO 17
Actions:
7003: MESSAGE 40
7005: DONE
7f87: PLOV _ Conditions:
7007: AT 58
7009: NOTZERO 17
700b: ZERO 18
Actions:
700e: PLACE 43 58
7011: GOTO 26
7013: SET 0
7015: DESC
7016: DONE
7f8b: PLOV _ Conditions:
7018: AT 58
701a: NOTZERO 17
701c: NOTZERO 18
Actions:
701f: MINUS 30 10
7022: PLACE 43 58
7025: SET 0
7027: GOTO 26
7029: DESC
702a: DONE
7f8f: PLOV _ Conditions:
702c: AT 26
702e: NOTZERO 17
7030: ZERO 18
Actions:
7033: PLACE 43 58
7036: GOTO 58
7038: CLEAR 0
703a: DESC
703b: DONE
7f93: PLOV _ Conditions:
703d: AT 26
703f: NOTZERO 17
7041: NOTZERO 18
Actions:
7044: MINUS 30 10
7047: PLACE 43 58
704a: GOTO 58
704c: CLEAR 0
704e: DESC
704f: DONE
7f97: PLOV _ Conditions:
Actions:
7052: MESSAGE 40
7054: DONE

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Strident
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Re: Colossal Cave Adventure (Anubis Software)

#2 Post by Strident » Thu Mar 24, 2022 8:51 pm

boldir wrote:
Thu Mar 24, 2022 6:42 pm
Hi,
I've tried to solve another Colossal Cave Adventure (the one from Ross Harris, Anubis Software, 1985 - I wonder why this is not in the 'Related' list), but there is a problem with the PLOVER command in Room Y2 (loc. 26) and in the Small chamber with the emerald (loc. 58); it doesn't work at all. Does anybody know what the conditions mean?
There's nothing hidden in the conditions... they're as read... They check the status of flags 17 and 18; whether they're zero or notzero. They're not system flags so it'll very much depend what Ross was using those two user-definable flags to indicate.

I'll have a nose in the code later and figure it out. Interestingly, some of those responses adjust the darkness/light system flag (flag 0).

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Strident
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Re: Colossal Cave Adventure (Anubis Software)

#3 Post by Strident » Thu Mar 24, 2022 9:12 pm

Hmm... that is interesting.

I can't find any instances of flag 17 being set anywhere, but it obviously needs to be SET for the Plover section to trigger.

Flag 18 is SET by the emerald being dropped inside the Well House.

So look like a bug, yes.

boldir
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Re: Colossal Cave Adventure (Anubis Software)

#4 Post by boldir » Sun Mar 27, 2022 8:14 pm

I also suspected it was a bug, but I'm not a programmer. Is it possible to fix the game?
By the way, there's another problem concerning the Spelunker's Gazette: This should be found in the anteroom (loc. 38) and should be dropped at Witts End (loc. 39), which scores 10 points, but the Gazette is nowhere to be found.

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Strident
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Re: Colossal Cave Adventure (Anubis Software)

#5 Post by Strident » Sun Mar 27, 2022 9:17 pm

I'll ask Ross if he can remember ever doing a bug fix for the game. There may be another version out there that needs to be archived.

The gazette does start as not created and there isn't any create code in the version of the game I'm looking at so, yes, that seems to be another bug too.

What should the required behaviour for the first PLOVER bug be? Colossal Cave isn't something I've ever been that interested in playing. I'm not sure what action should set the flag 17.

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auraes
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Re: Colossal Cave Adventure (Anubis Software)

#6 Post by auraes » Mon Mar 28, 2022 8:31 am

I have ported the game to zQuill. I don't know if I can put the code on my repository. It could be interesting to try to fix the bug.

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Strident
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Re: Colossal Cave Adventure (Anubis Software)

#7 Post by Strident » Mon Mar 28, 2022 9:47 am

I've asked the author Ross and he says he doesn't remember releasing a bug-fixed version.

The bugs are technically very easy to fix. The gazette object just needs to have its starting location set appropriately, rather than not created as originally. Flag 17 just needs to be SET at the appropriate time so that PLOVER works as intended.

What would be trickier would be applying the fixes to the Spectrum game and exporting everything so it is released in the same standard of presentation as the original game. It may be just better to flag the bugs up in any solution and mention that obtaining maximum points is not possible because of them.

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auraes
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Re: Colossal Cave Adventure (Anubis Software)

#8 Post by auraes » Mon Mar 28, 2022 1:31 pm

Location 58 shows a NE exit when it is E.
I put object 57 in location 38, and set flag 17 here:

Code: Select all

EMER _   Conditions:
            PRESENT  42 
         Actions:
            SWAP     42   43 
            PLUS     30    5 
            PLUS     26    1
            SET      17
This prevents you from teleporting from location 26 to location 58 without first visiting location 58. I don't know if this fixes the issue.
Last edited by auraes on Thu Mar 31, 2022 3:52 am, edited 1 time in total.

Alastair
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Re: Colossal Cave Adventure (Anubis Software)

#9 Post by Alastair » Mon Mar 28, 2022 10:53 pm

boldir wrote:
Thu Mar 24, 2022 6:42 pm
[...] there is a problem with the PLOVER command in Room Y2 (loc. 26) and in the Small chamber with the emerald (loc. 58); it doesn't work at all.
My apologies for not noticing this earlier, but you cannot use PLOVER when carrying the emerald, you must remove the emerald from the Plover room by some other way. If you are not carrying the emerald and you still can't move between Y2 and the Plover room using PLOVER then there is a bug in the program.


Strident wrote:
Sun Mar 27, 2022 9:17 pm
Colossal Cave isn't something I've ever been that interested in playing.
You heretic!

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Strident
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Re: Colossal Cave Adventure (Anubis Software)

#10 Post by Strident » Mon Mar 28, 2022 11:08 pm

Alastair wrote:
Mon Mar 28, 2022 10:53 pm
You heretic!
I'm not at all bothered about Infocom, either. ;)

Colossal Cave and Infocom weren't particularly part of my text adventure journey (although I did play a couple of Infocom games) so I have no real nostalgia for those titles.

In this particular adaptation, the emerald blocking PLOVER from working is actually programmed in... that's what flag 18 does... it's SET (notzero) when you drop the emerald and cleared (zero) when you pick it up.

Flag 17 is the area that the issue is around. PLOVER won't activate until it's set, you just get a "Pardon!" response... so I guess it needs to be set when the player discovers the magic word?

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Re: Colossal Cave Adventure (Anubis Software)

#11 Post by Alastair » Mon Mar 28, 2022 11:37 pm

Strident wrote:
Mon Mar 28, 2022 11:08 pm
Flag 17 is the area that the issue is around. PLOVER won't activate until it's set, you just get a "Pardon!" response... so I guess it needs to be set when the player discovers the magic word?
There are a couple of ways that this may be set in the game (there may be more but these are the two I have seen used). The first is simply entering the Plover room (which from Boldir's description is location 58), the other is saying Plover whilst in the Plover room when you are not carrying the emerald. If neither condition can be seen in the game then simply setting Flag 17 when you enter location 58 should suffice.

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auraes
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Re: Colossal Cave Adventure (Anubis Software)

#12 Post by auraes » Tue Mar 29, 2022 6:24 am

boldir wrote:
Sun Mar 27, 2022 8:14 pm
By the way, there's another problem concerning the Spelunker's Gazette: This should be found in the anteroom (loc. 38) and should be dropped at Witts End (loc. 39), which scores 10 points, but the Gazette is nowhere to be found.
It is possible to fix this on the .tap or .tzx file. In a hexadecimal editor, look for the sequence in Hexadecimal: 10 11 69 2E FC 52 FC and replace the last FC by 26 (all values are in hexadecimal). I don't know why the sequence appears twice.
For the flag 17 it's more tricky, because nothing should be crushed.

boldir
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Re: Colossal Cave Adventure (Anubis Software)

#13 Post by boldir » Sat Apr 09, 2022 11:36 am

I've now fixed the game so that it's solvable - fixed game, solution and map follow soon.

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auraes
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Re: Colossal Cave Adventure (Anubis Software)

#14 Post by auraes » Sat Apr 23, 2022 10:11 am

There is also an 'OK' instruction missing in this action block:

Code: Select all

GET   OIL        AT            49
                 PRESENT       58
                 SWAP          58  60
                 DONE  
Just replace the 'DONE' with 'OK'.

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