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Chihiro game sizes, 512MB vs 1GB

rtw

rtw

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I recently got hold of a Chihiro and I'm trying to learn more about this system.

One of the first things I did was to update the memory to 1GB.

However I am wondering if there are any games which require 1GB to run ?
 
Chihiro is weird, there are a number of games that came with alternate discs depending on if the system had 1GB or 512MB.

Personally I have mine setup with 1GB and then use all the 1GB images.

There are a couple of games that require 1GB, I think GBOS, the OR2 Prototype, and one of the Ghost Squad versions, though I could be wrong?

I feel that there must be some difference between the 512MB and 1GB game variants the image sizes of the 1GB variants are usually slightly larger so I'm guessing maybe they did additional music, fmv, or texture compression on the 512MB versions to get them under the threshold. This is just pure speculation on my part though.
 
I have all 4 of mine at 512MB. I just play the driving games, and they all have 512MB versions, AFAIK. I'm pretty sure I have an OR2 prototype, but @twistedsymphony mentions it may require 1GB, so I'm not sure on that one. I had my original system set to 1GB, so not sure if I was playing around with the prototype at that time.
 
if you have type 3 is very easy to upgrade to 1gb RAM this is standard RAM set (old DDR1 or 2...). I assume that only compression data no differrence except loading time. 512 could be longer. RAM is here only stock game.
 
Time to find out what is really going on here :D

I took the Outrun 2 CHD from MAME, extracted the two images (512MB/1GB), decrypted them and then extracted the files from each of these FATX images files and compared them.

The contents were exactly the same!

So I started looking at the two images, using your favourite hex editor open up the two files and search for: boot.id

In the 512MB image you will find it at: 0x11000
In the 1GB image you will find it at: 0x21000

Then I took the 1GB image and removed 0x10000 bytes before offset 0x21000.

>md5sum OUTRUN2_1GB_D.BIN OUTRUN2_512MB_D.BIN

5f11ebe526af10b8989fe38a0dbbba59 OUTRUN2_1GB_D.BIN
5f11ebe526af10b8989fe38a0dbbba59 OUTRUN2_512MB_D.BIN

If you remove these 0x10000 bytes the FATX images are exactly the same!

I did the same test with: Outrun 2 Special Tours and the result is exactly the same.

It looks like if the: boot.id is found at: 0x11000 it's a 512 MB game.

This means that: Outrun 2 Prototype is for a 512 MB setup.
 
Is there any possibility the extra 512mb ram if identified gets used as extra video ram? I tried running the 512mb and the 1gb of wmmt 2 at the same time and the 1Gb picture looked sharper. My problem is the monitors were different types and brands so i dont know if i was just seeing things.

The other question would be is the extra ram being used as a scratch pad for the cpu?
 
@rocket I don't think that the extra memory can be utilized by the base board.

The DIMM is just a reprogrammable "cart". On the NAOMI is was introduced as a cheaper way of supporting more games.
Load the game to the DIMM memory from GD-ROM, but the rest of the NAOMI treats it as a cart.
 
I just think some chihiro's got delivered with 512MB and maybe others with 1GB of ram.
Due to that, they released 2 versions of the games as a 512MB game won't run on a 1GB unit.
As you said, the dimm appears to the system as a solid state drive (using sdram instead of flash)
Outrun2SP also uses a small partition on the dimm for it's high scores and game settings.
Other games use the battery backupped ram on the base board for that.
To be honest, I have never seen a chihiro that came out of the factory with 1GB ram.
If you extracted and compared the files and found them to be identical, than I don't see how the game could play any different.

So, the dimm memory upgrade to 1GB is in fact useless. It might even take a bit longer to upload a 1GB image as they are a bit longer.
This is due to the image file allocation table size that has to be bigger as well to have room for 1GB of sectors.
(So it's double in size) That's probably the area you could safely removed before you made the compare.
boot.id is the first file on the game fatx image. So it's name should appear just after the file allocation table.
 
obcd said:
To be honest, I have never seen a chihiro that came out of the factory with 1GB ram.
Click to expand...
They exist, I own one. Though I couldn't tell you what game was installed originally.

9436322272_95f3356059_b.jpg

I had a second 1GB Chihiro as well that I sold. both of them came from Japan and both of them had 2x 512MB sticks... also interestingly both of them had been "downgraded" to 512MB with the extra stick removed and taped to the inside of the media board housing.
 
iirc later versions of Chihiro satellite games series (Quest of D, Sangokushi Taisen, Mobile Suit Gundam Card Builder) was quite large, so, I'd guess 1GByte Chihiro units was made for these games.
 
I bet one day we'll be loading our games from compact flash basically bypassing the dimm memory all together.
It will allow faster boot times (as loading the game initially from gdrom, compact flash or netbooting it won't be needed anymore.

I am glad the 1GB mystery has been solved.
 
rtw said:
Time to find out what is really going on here :D

I took the Outrun 2 CHD from MAME, extracted the two images (512MB/1GB), decrypted them and then extracted the files from each of these FATX images files and compared them.

The contents were exactly the same!

So I started looking at the two images, using your favourite hex editor open up the two files and search for: boot.id

In the 512MB image you will find it at: 0x11000
In the 1GB image you will find it at: 0x21000

Then I took the 1GB image and removed 0x10000 bytes before offset 0x21000.

>md5sum OUTRUN2_1GB_D.BIN OUTRUN2_512MB_D.BIN

5f11ebe526af10b8989fe38a0dbbba59 OUTRUN2_1GB_D.BIN
5f11ebe526af10b8989fe38a0dbbba59 OUTRUN2_512MB_D.BIN

If you remove these 0x10000 bytes the FATX images are exactly the same!

I did the same test with: Outrun 2 Special Tours and the result is exactly the same.

It looks like if the: boot.id is found at: 0x11000 it's a 512 MB game.

This means that: Outrun 2 Prototype is for a 512 MB setup.
Click to expand...
So do you succes to extract all file from this (like the executable....)?
 
Wasn't the extraction done to (try to) play the games on a 128MB modded xbox?
I seem to remember there is a tool on github created by JayFoxRox.
There also is a fuse fatx solution for linux. You can mount the fatx image and extract it's files.
 
THX. I dumped with my dreamcast the .bin from GDROM disk OR2. Inside 2 file one for 512 and one for 1GB. The problem is extract file from this bin
 
I think some of the Type-1 Games were actually patched to play on an Xbox with upgraded RAM there are quite a few videos on Youtube showing this off.
 
not really. 3 games no need patch, just extract and run the executable. Jayfox from assemblergames make a little program can launch ghost squad.
 
If you have an image from a gdrom, you will need to decrypt it first.
For that, you need the decryption key that is located in the security chip.
After decryption, the image should start with FATX followed by a number of either
0xff or 0x00 bytes (starting at 0x12) Next, you can use the tool from jayfoxrox to extract
the binary into it's files.
Just pm me if you need the python decryption program to decrypt the image.
 
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