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Proper Nintendo 64 fomat? #34391
10/08/07 03:56 PM
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ReadOnly Offline OP
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I currently search the 1:1 byte accurate format for the N64.
How is the data arranged in the Mask ROM? Big Endian, Little Endian, Byte swapped?

Could someone point me to some dirrections?

Re: Proper Nintendo 64 fomat? [Re: ReadOnly] #34392
10/08/07 04:38 PM
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R. Belmont Offline
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The actual mask ROMs are custom ones using a RAMBUS protocol, so there is no way to read them directly. Guru had to use a modified N64 copier device to read the Aleck64 arcade games.

Re: Proper Nintendo 64 fomat? [Re: R. Belmont] #35425
11/05/07 01:32 PM
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Originally Posted By R. Belmont
The actual mask ROMs are custom ones using a RAMBUS protocol, so there is no way to read them directly. Guru had to use a modified N64 copier device to read the Aleck64 arcade games.
I'm confused... did Guru read the Aleck64 ROM direcly or not?

The Aleck64 ROM images currently in MAME are 1-byte swapped, does it mean console ROM have byte spped data too?

Re: Proper Nintendo 64 fomat? [Re: ReadOnly] #35437
11/05/07 07:55 PM
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Arbee just said:

Aleck games were dumped by an N64 copier. As such, the reasonable expectastion is that the data is in fact in a copier format, which may or may not be the same as the MaskROms, which use a rambus protocol and thus are not directly dumpable by Guru at this time.

Re: Proper Nintendo 64 fomat? [Re: Heretical_One] #35439
11/05/07 08:23 PM
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Thanks for the clarification H_O.
Let's hope Guru can get thro this rambus protocol and get a direct ROM dump in the future? frown

Re: Proper Nintendo 64 fomat? [Re: ReadOnly] #35444
11/05/07 09:51 PM
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Why do you care? Don't get me wrong, "proper" dumps are nice, but it's certainly not as important for the N64 as it is for the NES; the NES has multiple ROMs with different purposes (CHR and PRG) concatenated together, whereas there's no such distinction for the N64. Are you just looking for something Nintendo-related to bug people about since folks called you out for asking about SNES with every new MESS release?

Re: Proper Nintendo 64 fomat? [Re: MooglyGuy] #35448
11/05/07 10:02 PM
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That said, since RAMBUS is serial, one would assume that whichever order results in big-endian pointers and readable text is correct, but I wouldn't put anything past Nintendo.

IMO there are a lot of dumping related things that are far more urgent (I'd like to see solid technical data instead of handwaving about correct dumping of CDs with mixed track types, for instance). We're losing no data with N64 carts (unlike NES where we lose what data goes in which chip) and if it turns out the current Aleck dumps are wrong we'll byteswap them.

Re: Proper Nintendo 64 fomat? [Re: MooglyGuy] #35451
11/05/07 11:33 PM
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Originally Posted By MooglyGuy
Why do you care? Don't get me wrong, "proper" dumps are nice, but it's certainly not as important for the N64 as it is for the NES; the NES has multiple ROMs with different purposes (CHR and PRG) concatenated together, whereas there's no such distinction for the N64.
Our project (No-Intro) is aiming 1:1 accuracy. And such accuracy includes byte order in the Mask ROM. In the past we figured out the byte order inside the ROM chip is sometimes different then the order at the PCB pins. We corrected the NEC PC-Engine set, which used byte swap in US cards (as a form of encryption/region protection) among others. Same for the SEGA Megadrive... We will always use the order in the ROM chip for maximum accuracy.

Originally Posted By MooglyGuy
Are you just looking for something Nintendo-related to bug people about since folks called you out for asking about SNES with every new MESS release?
You don't make the slightiest sense. Don't be a rude and stop flamebaiting please. We're talking about serious buisness here.

Last edited by MESSfan; 11/06/07 12:01 AM.
Re: Proper Nintendo 64 fomat? [Re: ReadOnly] #35453
11/06/07 12:09 AM
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Originally Posted By MESSfan
Our project (No-Intro) is aiming 1:1 accuracy. And such accuracy includes byte order in the Mask ROM. In the past we figured out the byte order inside the ROM chip is sometimes different then the order at the PCB pins. We corrected the NEC PC-Engine set, which used byte swap in US cards (as a form of encryption/region protection) among others. Same for the SEGA Megadrive... We will always use the order in the ROM chip for maximum accuracy.
Okay, now that it's known why you were asking, it makes more sense. Still, given how protective Nintendo are over technological details, there's the chance that a "proper" dump may never be obtained.

Originally Posted By MESSfan
You don't make the slightiest sense. Don't be a rude and stop flamebaiting please. We're talking about serious buisness here.


I'm sorry, I've just become a bit cynical regarding your intentions after three consecutive MESS versions of "why no SNES progress? frown frown "

Re: Proper Nintendo 64 fomat? [Re: MooglyGuy] #35493
11/06/07 07:17 PM
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According to a project fellow, Guru is pretty sure the mask rom data is byte swapped regardless of the rambus. I suppose Guru knows what he is talking about. No-Intro will shortly convert the N64 set to byteswapped. (hopefully MESS supports it)

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