News: 11 March 2016 - Forum Rules
Current Moderators - DarkSol, KingMike, MathOnNapkins, Azkadellia, Danke

Author Topic: Reinsert Larger files in PSX ISO  (Read 2631 times)

Miles_V

  • Jr. Member
  • **
  • Posts: 3
    • View Profile
Reinsert Larger files in PSX ISO
« on: March 23, 2016, 02:38:46 pm »
Hi, I started a project undubbing the following games: MegaMan 8 and Tomba 2, in the case of Tomba 2 is change all the OST for the original one.

Off course I have both version of the game and in the case of Megaman 8 it sound easy because is about of replace the files, but the real problem is that: the files that I want to replace are larger than original ones and if I proceed to replace these files (22 of these files) I'll corrupt the game.

Note: I tried changing the TOC placing the larger file in the Dummy File and reinsert it but when I start the game it not have change.  :'(

My question is how I can Rebuild a PSX CD based in a retail game? (Note: I tried PSX ISO Maker Pro and Ultra ISO and doesn't work).

or if I have to edit these file? but the audio file of Megaman 8 are in PAC with multiple sample inside of the files  :-\.

I can convert it to WAV using PSound and edit it using a audio editor, but how I can reconvert it back and repacking into the PAC file?

viewing these files in a hex editor they have similitude with the XA files, I think I must start whit that   :huh:

NERV Agent

  • Restricted Access
  • Sr. Member
  • *
  • Posts: 497
  • Eva Unit 01
    • View Profile
    • Watch my anime shitposts on YouTube! Smell them, too!
Re: Reinsert Larger files in PSX ISO
« Reply #1 on: March 24, 2016, 04:04:28 am »
Hopefully this can be of help:

http://www.romhacking.net/forum/index.php?topic=13272.0

Good luck!

BlackDog61

  • Hero Member
  • *****
  • Posts: 784
    • View Profile
    • Super Robot Wars A Portable translation thread
Re: Reinsert Larger files in PSX ISO
« Reply #2 on: March 25, 2016, 09:15:48 am »
Does it also not work when you simply remove the dummy file?
Some games would have "hard coded disk addresses", which could be another cause for the symptom you described. The test would rule it out (since dummy is typically before.most files, to accelerate data access).

Miles_V

  • Jr. Member
  • **
  • Posts: 3
    • View Profile
Re: Reinsert Larger files in PSX ISO
« Reply #3 on: March 25, 2016, 09:58:50 am »
Talking about the TOC and he Dummy files, Megaman 8 has 2 Dummy Files : ZNULL.DAT and END1.DA

as you can see the LBA of these files are in the end of the iso

The 22 files that I want replace are the following files:

but these files are larger than the original ones.

I show the list complete of files in the sound folder of Megaman 8



1- How I can verify if the game have a hard code disk addresses or a strict structure that not allow read the file if doesn't is in the original LBA?

2- What I must do if the game have a hard code disk addresses or a strict structure?
« Last Edit: March 25, 2016, 10:05:20 am by Miles_V »

BlackDog61

  • Hero Member
  • *****
  • Posts: 784
    • View Profile
    • Super Robot Wars A Portable translation thread
Re: Reinsert Larger files in PSX ISO
« Reply #4 on: March 26, 2016, 07:31:36 pm »
1- How I can verify if the game have a hard code disk addresses or a strict structure that not allow read the file if doesn't is in the original LBA?
Move 1 file in the LBA without even changing the size?

2- What I must do if the game have a hard code disk addresses or a strict structure?
Change the ASM or data that manages it. This would be game-specific, so firing up the debugger & tracing things is the way to go. Again,*IF* this is what is happening here. (no proof yet)

Gemini

  • Hero Member
  • *****
  • Posts: 2026
  • 時を越えよう、そして彼女の元に戻ろう
    • View Profile
    • Apple of Eden
Re: Reinsert Larger files in PSX ISO
« Reply #5 on: March 26, 2016, 09:06:38 pm »
Most CAPCOM games use a simple list of lba and size, in some cases with one byte of the lba used for checksums. Megaman 8 should follow exactly this same trick to access file, editing TOC is useless as it comes.
I am the lord, you all know my name, now. I got it all: cash, money, and fame.