Acorn Arcade forums: Games: Pandora's Box
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Pandora's Box |
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sirbod (21:40 4/9/2012)
apdl (06:08 5/9/2012)
sirbod (08:37 5/9/2012)
apdl (06:12 6/9/2012)
sirbod (10:09 7/9/2012)
sirbod (11:36 11/9/2012)
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Jon Abbott |
Message #120985, posted by sirbod at 21:40, 4/9/2012 |
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Posts: 563
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I know an SA version came out in '98 (anyone have the floppy?), but is there a patch for the original, to get it working on RO3? Did Fourth Dimension release any patches between '91 and '98?
It appears the file "Basic" has some compatibility issues, but I think the problem may be in the "Core" code.
I found a patch for the SA version on APDL's site, but comparing the code, it looks like it expects a protection stripped copy of the game and has also been hard coded to use the hard disc for saves. |
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David Holden |
Message #120986, posted by apdl at 06:08, 5/9/2012, in reply to message #120985 |
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I found a patch for the SA version on APDL's site, but comparing the code, it looks like it expects a protection stripped copy of the game and has also been hard coded to use the hard disc for saves. That's because, as it says, it's a fix for a problem with early copies of the version we supply. It's no use for the old original version. |
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Jon Abbott |
Message #120987, posted by sirbod at 08:37, 5/9/2012, in reply to message #120986 |
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Yes, I did read that and simply compared the code to see what had changed. It was the only patch I could find on the net, so was worth a look.
The reason I'm trying to get the original version working, is to check the protection works under ADFFS, it uses a unique combination of disc layout, disc descrambling and vector hijacking. The only other game that uses something similar is Cataclysm, which uses a variation on the Gremlin protection module - I've yet to determine if Cataclysm's disc layout is similar as I don't have a copy to look at.
I believe ADFFS does handle this protection, but would like to confirm by seeing it actually run.
Up to the point it crashes, the only protection check is to see if a CRC error occurs on one sector (159.4). The disc however has 97 protection sectors on it, scattered throughout the disc and three unformatted tracks at the end. It seems a little odd to go to all those lengths and check only one sector. My guess is that further disc checks may be done within the game.
[Edited by sirbod at 12:53, 7/9/2012] |
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David Holden |
Message #120988, posted by apdl at 06:12, 6/9/2012, in reply to message #120987 |
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OK, that makes sense.
If you're trying to get some of the really ancient copy protected stuff to work you should be aware that some of the early games used nasty tricks like 'bashing' the 1772 FDC chip directly. This only works on the 300, 400 and 3000 which used this chip and not on later models which used different hardware. So if you can't get a very ancient game to load with ADFFS that might be the problem. |
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Jon Abbott |
Message #120992, posted by sirbod at 10:09, 7/9/2012, in reply to message #120988 |
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some of the early games used nasty tricks like 'bashing' the 1772 FDC chip directly. This only works on the 300, 400 and 3000.
The only one I'm aware of that exploits the 1772 explicitly in Slappit, although I suspect the other RTFM games may be similar. It actually exploits a bug in the 1772*, that to date hasn't been documented, and isn't supported in any emulator that I'm aware of.
If you know of any other games, please let me know, drop me an eMail.
* On further thought, it's more likely this is a bug or feature in the RISC OS 1772 read track code, as a 1772 read address command does not return data.
[Edited by sirbod at 09:50, 9/9/2012] |
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Jon Abbott |
Message #121046, posted by sirbod at 11:36, 11/9/2012, in reply to message #120985 |
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Turns out the original Pandora's Box works fine, unpatched, with the protection intact on a SA, and on RO3.1 to RO3.7 and possibly above.
The fix was:
Screen Size: 224K
Sprite Size: 8K |
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Acorn Arcade forums: Games: Pandora's Box |
