Documentation (Prince of Persia 1 for SNES Regional Differences)

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Documentation (Prince of Persia 1 for SNES Regional Differences)

Postby Norbert » September 25th, 2015, 1:53 pm

I have finished the first version of a document that describes the regional differences between Prince of Persia 1 for SNES releases:

2015-09-25_PoP1_for_SNES_Regional_Differences.pdf

The source document (.odt; OpenDocument) is also available, here.
Its main page on popot.org is here.
Feedback is welcome. Just post it in this thread or send an e-mail.

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Re: Documentation (Prince of Persia 1 for SNES Regional Differences)

Postby Norbert » September 25th, 2015, 3:35 pm

Several of the changes from JP to US are self-explanatory. The removal of the pentagram is most likely because of its perceived association with Satanism/occultism. (Maybe also socialism/communism/religions/magic.) Somewhat related articles here and here. The Japanese version even contains a(n unused) Star of David. However, the document raises several interesting questions:
- Why have the cloud backgrounds of the fawn levels (pink palace) been moved after the other backgrounds?
- In the marble levels (red palace), why have the backgrounds with pink been changed? (They aren't even used in any levels, are they?)
- In levels 4 and 5, why have those extra bits (100 decimal) been removed from those locations? (They are not animation related, I think.)
- In levels 4 and 19, why have events (and related raise buttons) been flipped? (In fact, in both levels, one of the changed pairs isn't even in use.)

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Re: Documentation (Prince of Persia 1 for SNES Regional Differences)

Postby David » September 26th, 2015, 4:13 pm

Norbert wrote:- In levels 4 and 5, why have those extra bits (100 decimal) been removed from those locations? (They are not animation related, I think.)

"not animation related":
But I think they are.
As I wrote on the wiki, the "Block flags and background animation info" is actually two arrays.
The first (bits 0-1) is indexed by foreground tile and contains floor and wall flags.
The second (bits 2-7) is indexed by background tile and contains animation group IDs.
The differences are in the second one. It just follows the move of the cloud graphics.

Norbert wrote:- In levels 4 and 19, why have events (and related raise buttons) been flipped? (In fact, in both levels, one of the changed pairs isn't even in use.)

"isn't even in use":
The first swapped pair is marked as "trigger next" in each case.
So the second pair is used indirectly.

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Re: Documentation (Prince of Persia 1 for SNES Regional Differences)

Postby Norbert » September 26th, 2015, 6:12 pm

David wrote:So the second pair is used indirectly.


Oh, yeah.

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Re: Documentation (Prince of Persia 1 for SNES Regional Differences)

Postby Norbert » October 6th, 2015, 11:47 pm

Small correction, if there's ever an updated version of the document:
On page 7, 0x2C-0x43 should be 0x2B-0x42.

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Re: Documentation (Prince of Persia 1 for SNES Regional Differences)

Postby Norbert » April 20th, 2017, 3:23 am

Why do we even think there are EU and US versions of PoP1 for SNES?
Only 3(!) bytes differ between these two versions.
Isn't it more likely that someone modified the (single) non-JP version, and then people thought there are two non-JP versions?

At offset 0x7FD9, there's:
- US: 01 A4 00 32 41 CD BE
- EU: 02 A4 00 31 41 CE BE
(The JP version has 00 DD 00 C9 8A 36 75 there. Slightly related is this post.)

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Re: Documentation (Prince of Persia 1 for SNES Regional Differences)

Postby salvadorc17 » April 21st, 2017, 9:15 pm

Norbert wrote:Why do we even think there are EU and US versions of PoP1 for SNES?
Only 3(!) bytes differ between these two versions.
Isn't it more likely that someone modified the (single) non-JP version, and then people thought there are two non-JP versions?


Youre sure about that, no different passwords or screen/game speed??

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Re: Documentation (Prince of Persia 1 for SNES Regional Differences)

Postby David » April 22nd, 2017, 6:28 pm

Norbert wrote:Why do we even think there are EU and US versions of PoP1 for SNES?
Only 3(!) bytes differ between these two versions.
Isn't it more likely that someone modified the (single) non-JP version, and then people thought there are two non-JP versions?

Couldn't that "someone" be the developer or the publisher?
Maybe the console checks the value of the country code, similarly to DVD region codes?

Norbert wrote:At offset 0x7FD9, there's:
- US: 01 A4 00 32 41 CD BE
- EU: 02 A4 00 31 41 CE BE
(The JP version has 00 DD 00 C9 8A 36 75 there. Slightly related is this post.)

According to these docs:
* the 01/02/00 byte is the country,
* the A4/DD byte is the Developer ID code,
* the 00 byte is the ROM Version number,
* the remaining 4 bytes are the Checksum and its complement.

salvadorc17 wrote:Youre sure about that, no different passwords or screen/game speed??

Passwords are the same.

About the speed: The US version seems to be faster. I guess that's because the game's speed is synced to the framerate.
But that does not tell who changed the ROMs.

This walkthrough by Christian Wall mistakenly claims that the USA version matches the Japanese, and differs from the European, based on the fact that USA and Japanese both use NTSC.

The covers on MobyGames list the following countries:
* United States, Canada and Mexico (NTSC) -- This is the US version.
* Japan (NTSC) -- This is the JP version.
* Germany (PAL) -- This is the EU version.
* Australia and New Zealand (PAL) -- Um. Since it's PAL, this is probably the EU version?
The list of country codes says that 02h is for "Europe, Oceania, Asia", but then it also lists 11h for Australia specially.

And then there is the list of releases...

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Re: Documentation (Prince of Persia 1 for SNES Regional Differences)

Postby Norbert » April 22nd, 2017, 7:27 pm


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Re: Documentation (Prince of Persia 1 for SNES Regional Differences)

Postby David » April 23rd, 2017, 11:02 am

Norbert wrote:Nice find, that document https://github.com/gilligan/snesdev/blo ... llsnes.txt

I have had a copy of that (and other console docs) for a few years.
It's originally here (HTML) and here (TXT).
I linked the copy on GitHub only because it lets me link to a specific line.


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