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Sebbeug

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Hello, owner of a CPS3 SF3 3.2 convert to 3.3, I try to edit the mention - DARKSOFT during boot.Personally, I would leave it well, because all the work goes to Darksoft himself (and thank you for that).
But in tournament, it is not necessarily appreciated by players....... ?(

What I already did :
I recovered the iso of the version A (3.2 to 3.3) and on the CD1, I edited the file 10 with an hexa editor (and replaced text by "20" bytes).
The trouble is after .. I recreated an .iso, burned it and made a REWRITE ALL with the CD1 ... But it does not work. The CD is well recognized, the writing is done (35min), but the game does not boot, I have an error message with THIRD STRIKE title.
I managed to get back to the original state by doing a REWRITE ALL with the "original Darksoft CD1".
CRC check? ISO format? For exemple I'm not able to have the same .iso size.

or if a, .iso "without text" version of 3.2-to-3.3 already exists...

Thank you, help is welcome ;)
 
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Why not just use Darksofts latest version of the multi disc that removes his name from the opening screens?
*NEW* April 12th 2019. Unmodified UniCD Images without Darksoft text for competitions. Requested by our Japanese friend TMZ
*Warning* Unless you are also using a special BIOS, when holding Start/re-writing games it still says "Darksoft - Menu" at the top.
The games however, once booted do NOT contain any special text.
 
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CRC check? ISO format? For exemple I'm not able to have the same .iso size.

or if a, .iso "without text" version of 3.2-to-3.3 already exists...
Yes there is a CRC check. If you modify the isos you need to update the CRC. AFAIK there is no released version of 3.2 to 3.3 without DARKSOFT text but you can make it yourself. I believe this is so that people can't profit off of conversions that are sold as original.
Why not just use Darksofts latest version of the multi disc that removes his name from the opening screens?
he is not talking about using a multi bios cart... he is talking about using the older method of converting CDs to use a different key. specifically making 2 cds that have the 3.3 data encrypted with the 3.2 key. And then you do a double cd load to the simms to get the full game loaded with the 3.2 cart.
 
he is not talking about using a multi bios cart... he is talking about using the older method of converting CDs to use a different key.
Ah, yea I only know about multi BIOS cart thingies. ;)
 
Thank you for your answers. I will try it and let you know.
 
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Yes, there is a CRC, which is just a byte by byte addition, so if you add all the bytes one by one (3A+5F+4E+00+FA) at the end you get a number i.e. 3A4F52EE. The last byte (EE) is the important one. Make all the changes, check again the CRC and modify as needed so you get the same last byte.
I don't undestand these steps...
We are talking about .iso file or files inside ?

CD used : SFIII_3rd_Strike_RevA_converted_for_SFIII_2nd_Impact_cartridge.CD1.iso, CRC32 = 9B336911
 
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Ok, new tests...
I extracted the file named : 10 (It's on this file we can find the boot text)
CRC32 is : DEB77E46

I edited this file with my changes (under WinHex), now CRC32 is : F74E4446

As described by @Darksoft, we find the same last byte (46)
 
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@Sebbeug that ISO is if you intend to use a working, battery-powered 2nd Impact Cart. Then you need that CD and the extra SIMM needed.

If you want to edit any of the files in that CD, then you need to adjust the CRC for each file changed.

If you use Super BIOS, then the CRC check is eliminated and you can make any changes to the CD.
 
Yes, there is a CRC, which is just a byte by byte addition, so if you add all the bytes one by one (3A+5F+4E+00+FA) at the end you get a number i.e. 3A4F52EE. The last byte (EE) is the important one. Make all the changes, check again the CRC and modify as needed so you get the same last byte.
I don't undestand these steps...We are talking about .iso file or files inside ?

CD used : SFIII_3rd_Strike_RevA_converted_for_SFIII_2nd_Impact_cartridge.CD1.iso, CRC32 = 9B336911
You can edit the hex data any way you want, either via the iso file or the files inside. Or you can modify the c code to not append the text in the first place. It's all just binary data.

I have it working locally, but I don't want to share the image publicly for fear of bootleggers. I use it to force my Asia region 3s to boot as USA.
 
@Darksoft i just bought a 3.2 convert to 3.3 which is working good. So i got the 3.2 cartridge and the extra SIMM.


Just burned my 6th CDROM :D
and always an error message at the end of rewriting, just before booting.
Probably the CRC check.

So :

I edited the 10 files..... As i said, CRC was DEB77E46 on initial file.
Last bytes of this file are : D1 9C (Only 2 bytes to probably have the good CRC ?)

crc.jpg



I change CRC of my edited file with the good one (using a little tool : CRC manip - This tool add 4 bytes to the end of my file)

1- I tried to delete the 2 bytes and replace it with my new 4 bytes .........> didn't work
2- I tried to add the 4 bytes after the original 2 bytes (6 bytes at the end of file)...............> didn't work

In these 2 cases, CRC of file was the good one : DEB77E46

I'm lost...
 
What you are doing, won't work. The CRC in CPS3 is calculated differently
Yes, there is a CRC, which is just a byte by byte addition, so if you add all the bytes one by one (3A+5F+4E+00+FA) at the end you get a number i.e. 3A4F52EE. The last byte (EE) is the important one. Make all the changes, check again the CRC and modify as needed so you get the same last byte.
I don't undestand these steps...We are talking about .iso file or files inside ?

CD used : SFIII_3rd_Strike_RevA_converted_for_SFIII_2nd_Impact_cartridge.CD1.iso, CRC32 = 9B336911
It's explained there. Each file has it's own CRC. It's calculated as explained above (Add the bytes of the file 1 by 1 ) and the final sum (it's 1 byte only) must match what was before you touched it, so if the sum of all bytes 1 by one is 3F456C71, you only are interested in the final 71.
 
Thank you @Darksoft,

But to adjust this CRC with correct sum ? What's the way ? A 8Mbits file = 8 millions of bytes to add one by one !
I'm not sure it exists a tool for that... I have to code a script...

Result should be a 16bits chain ?

The last 2 bytes of file only exist to match with the correct sum ? (D1 9C on my previous picture)
 
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Thanks to @Darksoft for sharing his knowledge !
Just edited the file and IT'S OK NOW !!!
I wrote a little python script for that.
If people interested, i will compile an .exe to patch all edited SF3.3 files.

A big 9 9 0 5 1 2 thanks !
 
Ok no problem, with pleasure.
I will compile a windows .exe...
 
ok no problem... :)
It's only a few lines...

Python 3+ with your files on same directory :


Code:
# Sum of all bytes in a file, byte by byte

file = open('name_of_your_file_here', 'rb')
data = bytearray(file.read())

total = sum(data)
hexa = hex(total)
final = hexa[2:]
key = final[-2:]

print("Sum of all bytes is :", total)
print("Hexadecimal format :", final.upper())
print("CPS3 Checksum key is :", key.upper())
With this, you can compare 2 files... And have informations to adjust your file after modifications.
For this, you only have to edit the 2 last bytes of the file to have the same "key". (i.e. D1 9C changed for D3 05 to have the same 12 "key")
(a little substration and an online hexa converter will be your friends)
 
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