Odd PFLOYD string in DKL...

Share and discuss all facets of DKC ROM hacking...

Odd PFLOYD string in DKL...

Postby Blaziken257 » January 31st, 2013, 7:38 am

No, I'm not making this up. At ROM offset 0x6F7A (in both the English and Japanese versions of Donkey Kong Land), you can find a PFLOYD string. It's followed by four other bytes, 00 00 05 03, and this ten-byte string is copied to AA00-AA09, AA40-AA49, and AA80-AA89 in RAM, for each of the three save files. (In a .sav file, this corresponds to A00-A09, A40-A49, and A80-A89, respectively.) It turns out that hacking this 6-byte string in RAM will cause a file to be erased (depending on which of the three strings you hacked), regardless of whether or not the checksum data (mentioned below) is correct, so it appears that its purpose is to detect corrupt data. (Once the file is erased, of course, the string ends up being restored.)

This is one of three mechanisms that DKL seems to use to detect corrupt files, the other two being two different checksums. The first checksum is addition-based, where it adds bytes from AA00-AA3D, and stores an 8-bit result in AA3E. The second checksum is XOR-based, where all the bytes from AA00-AA3D are XORed together and stored in AA3F. (For file 2, the bytes to add/xor are from AA40-AA7D, the first checksum byte is in AA7E, and the second checksum byte is in AA7F. For file 3, the bytes to add/xor are from AA80-AABD, the first checksum byte is in AABE, and the second checksum byte is in AABF.) Thing is, however, as previously mentioned, that even if these two checksums are correct, the PFLOYD string still needs to be there for the file to be intact. So, all three of these conditions must hold, or the file will be erased.

In any case, it's weird that of all things, there's a PFLOYD string in the game. Now, I've seen other games that use strings to check the integrity of data, but usually it's the game name or something. PFLOYD is just so odd and out of place; it's not something you'd expect from a Donkey Kong game. Something like DKLAND would make more sense to me. I wonder who at Rare came up with this...
Treasure Hunter
Bananas received 108
Posts: 333
Joined: 2008

Re: Odd PFLOYD string in DKL...

Postby Qyzbud » January 31st, 2013, 7:45 am

Strange indeed... so, who's the big Pink Floyd fan at Rare? Hmm... :scratch:

Perhaps that same person named the little robotic helper droid (Floyd) in Jet Force Gemini?


Floyd the Droid



I just happened upon this title screen for a completely unrelated game called 'Floyd the Droid':

Image

Now if that game used PFLOYD string it wouldn't be so peculiar... 'P' for Paul — the programmer's name.

But look at the top-right — Graphics by Harvey A. Kong Tin!

Coincidence?! Yes, I'm pretty sure it is. :P

Actually, you know what? Pink Floyd had a song called 'On the Run'! :o ...that's probably not a coincidence...


Riddles



It's funny, Pink Floyd were famous for their riddles/Easter eggs, I believe — one in particular that I know of. I wonder if Rare were trying to further a Pink Floyd mystery like the aforelinked Publius Enigma, by embedding this text?

This is probably crazy talk, but DKC and The Division Bell (Pink Floyd album with Publius Enigma relevance) were both released in 1994, and DKL came out in mid 1995, so they are from a very similar time.

Another thing I just realised — The Division Bell's album art is quite Rare relevant:


Giant heads



Image

Just last night I was thinking to myself that 'giant 3D heads' are a common sight in Rare's game landscapes...

Image Image

DK Island, Wizpig's head, Gruntilda's head, probably a few more... :huh:

I wouldn't even mention that last point, it's just such a coincidence that I was thinking about Rare's fascination with these statues/megaliths just last night, and then today I see that album cover, and it's another case of giant heads in a landscape!
Atlas Author
Bananas received 671
Posts: 3228
Joined: 2008


Return to ROM Hacking

Who is online

Users browsing this forum: No registered users and 1 guest