PSIV Hacking Progress

Hunt the source of evil as the millennium comes to an end.

PSIV Hacking Progress

Postby BigNailCow » Thu Mar 18, '10, 3:24 am

Greetings all. I'm a fairly experienced ROM hacker who's done extensive work with Shining Force 2 (that thread is fairly inactive as I rarely post there, but my editor and knowledge of SF2 is much more extensive than in that first post).

Anyway, I decided to take a look at PS4, and in the course of a day I have cracked the text compression by following trace logs. Unfortunately, it's quite impossible to edit the text in a hex editor because of how it's stored (as I'm sure you guys know by now), but I'll probably write a script to do it soon. Would you be interested in the technical aspects?

Now I've decided to seek out PS4 fan forums to make sure I'm not wasting my time, and I'm quite impressed by the amount of knowledge you guys have about the contents of the ROM. However, it looks like there are still some things you haven't figured out that prevent a full PS4 hack from happening.

Is there anything else you guys want me to find? It shouldn't be too difficult. In addition, I may consider making a simple ROM editor for PS4 sometime soon, if I'm able to find most of the remaining missing information.

Thanks!

Edit: Oh, and for the record, my knowledge of PS4 is limited, so I'll probably need your help on where to find certain things.

Progress:

3/17/10 - I've found the enemy formation data. There are ~512 different formations (wow!), and each area can pick between up to 32 of these. Unfortunately, it's all compressed, so no hex editing here either. They seemed to want to compress almost everything in this game, and they still had trouble fitting it in the expanded cartridge.

3/18/10: Did some more searching and found enemy palettes and part of their animation data.
Last edited by BigNailCow on Mon Apr 12, '10, 1:34 pm, edited 4 times in total.
BigNailCow
Citizen
Citizen
 
Posts: 7
Joined: March 2010
Achievements: 7

Re: PS4 Text Compression: Cracked!

Postby Snorb » Thu Mar 18, '10, 4:05 am

Welcome to the forums! =p

Now back on topic, something I am genuinely curious about, inspired by the Blood Axe, Spiral Slasher, and Monitor: Are there any unused text strings in the game that imply dummied out NPC data?
Read my social stuff!
The ramblings of an oldish geezer on Facebook.
@SnorbESnorb on Twitter. The "E" stands for "Everything."

Play my games!
The ArrrPG - A game I made about being a pirate. This be a first draft, matey! Though it plays just fine, clap yer eyes on th' eventual Revised an' Expanded Edition and you'll be pleased, by thunder!

Nakama: A Card Game of Magical Girls - A completely un-playtested card game about being a magical girl.

Well, excuse me while I defy all laws of logic and common sense and do it anyway.
User avatar
Snorb
Moderator
Moderator
 
Posts: 1440
Joined: July 2007
Location: Where I am.
Achievements: 124
Gender: Male

Re: PS4 Text Compression: Cracked!

Postby BigNailCow » Thu Mar 18, '10, 4:11 am

Do you mean unused dialogue, specifically? Like I said, I only know a moderate amount about the content of the game itself (I'm sure I haven't played it as much or messed around with the specific data as the rest of you, so I don't have a lot memorized). I found everything I did through looking at the ASM.

I'll work on getting a complete dialogue dump script and let you guys comb through it.
BigNailCow
Citizen
Citizen
 
Posts: 7
Joined: March 2010
Achievements: 7

Re: PS4 Text Compression: Cracked!

Postby Thoul » Thu Mar 18, '10, 6:26 pm

Welcome to the community! I was going to ask if you could do a text dump, but now I see you're already working toward that. It'd be really interested in seeing that and putting it up on the site. I'd also be happy to see any of the technical aspects you'd care to share. ROM hacking isn't my forté, but any new information about the game is welcome, especially if it might help uncover a way into some of the remaining areas that haven't been figured out yet.

On those enemy formations, can you tell if there's any kind of flag for a enabled or disabled formation? There are a few formations for one area of the game that are present in the Japan version of the game but missing in the English release. Other people have found that the enemies are still in the game code, just not enabled in some fashion.
User avatar
Thoul
Administrator
Administrator
 
Posts: 12923
Joined: March 2007
Location: USA
Achievements: 123
Gender: Male

Re: PS4 Text Compression: Cracked!

Postby Thoul » Sun Mar 21, '10, 8:33 pm

Oh, one other thing. A year or two ago, five prototype versions of PSIV were released as ROMs. They have some script differences. Could you check to see if they use the same compression? It would be great to get a text dump of the final game and one of the early prototypes for comparison.
User avatar
Thoul
Administrator
Administrator
 
Posts: 12923
Joined: March 2007
Location: USA
Achievements: 123
Gender: Male

Re: PS4 Text Compression: Cracked!

Postby BigNailCow » Mon Mar 22, '10, 10:44 pm

Alright! Script written, and I even made a nice autogenerating HTML page for it. I've only dumped one text block so far, because I don't know for sure how many there are or where they're at.

Edit: Continuing to add new pages...
http://bignc.ath.cx/ps4/
BigNailCow
Citizen
Citizen
 
Posts: 7
Joined: March 2010
Achievements: 7

Re: PS4 Text Compression: Cracked!

Postby Thoul » Thu Apr 8, '10, 2:10 am

I've skimmed through the lists (sorry it took so long - been busy) and didn't notice any unfamiliar text. It all looks like stuff that's in the game. Some of it is grouped kind of oddly, but there's nothing that stands out and makes me say "what's that?"
User avatar
Thoul
Administrator
Administrator
 
Posts: 12923
Joined: March 2007
Location: USA
Achievements: 123
Gender: Male

Re: PS4 Text Compression: Cracked!

Postby BigNailCow » Fri Apr 9, '10, 7:15 am

The formatting isn't perfect, and I also didn't extract all of the text. Most of it is probably still missing, in fact. I know how to get to it, but it'll be a bit of a pain. I've been finding other stuff in the meantime.
BigNailCow
Citizen
Citizen
 
Posts: 7
Joined: March 2010
Achievements: 7

Re: PS4 Text Compression: Cracked!

Postby BigNailCow » Mon Apr 12, '10, 1:21 pm

For those interested, I've released my first version of a hack that lets you compose a custom party using the Order menu, and all characters start at level 1; more information if you follow the link:
http://www.romhacking.net/forum/index.p ... 645.0.html

It includes instructions if you don't know how to patch a ROM. I could really use some hardcore PSIV fans to test this! :)
BigNailCow
Citizen
Citizen
 
Posts: 7
Joined: March 2010
Achievements: 7

Re: PSIV Hacking Progress

Postby Atlinsmere » Tue Apr 13, '10, 2:17 am

Wow. Sweet, I'll check it out later and tell you how it is.
A simple text based signature? That's impossible!
User avatar
Atlinsmere
Moderator
Moderator
 
Posts: 5027
Joined: July 2007
Location: Canada Eh.
Achievements: 392
Gender: Male


Return to Phantasy Star IV

Who is online

Users browsing this forum: No registered users and 0 guests