Need a guide or a fully walkthru on how to modify/rebuild psx games

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asianking
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Need a guide or a fully walkthru on how to modify/rebuild psx games

Post by asianking » February 17th, 2020, 5:35 pm

I was wondering if there is a guide out there to show us how to actually modify a psx games. For example, in Castlevania SOTN; I would like to know how we can find the real offset of starting hp/mp/hearts, store selling offsets and its price, etc... Once we have the offset; I need to know how we go about applying the changes to the game. I saw some post mention to use hex editor; others uses ppf, but there is really never a guide out there to walk a person from point A to point B at all. Much appreciated.

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Shadow
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Post by Shadow » February 17th, 2020, 6:57 pm

You can use an Xplorer and find memory changes to then lock or change the values, but the proper way is to find the function in the code by disassembling the machine code from the game and alter it. You need to know MIPS in order to do this and how the PSX CPU works, so this is why there are no 'guides' available. It's not an easy task and this is when you get into the realm of advanced software reversing.
Development Console: SCPH-5502 with 8MB RAM, MM3 Modchip, PAL 60 Colour Modification (for NTSC), PSIO Switch Board, DB-9 breakout headers for both RGB and Serial output and an Xplorer with CAETLA 0.34.

PlayStation Development PC: Windows 98 SE, Pentium 3 at 400MHz, 128MB SDRAM, DTL-H2000, DTL-H2010, DTL-H201A, DTL-S2020 (with 4GB SCSI-2 HDD), 21" Sony G420, CD-R burner, 3.25" and 5.25" Floppy Diskette Drives, ZIP 100 Diskette Drive and an IBM Model M keyboard.

asianking
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Joined: Feb 17, 2020

Post by asianking » February 17th, 2020, 7:02 pm

is it possible to combine xplorer and the game together so I don't have to do a disk swap if that is the case?

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