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Upping the Vram
Sonikusan - Jun 17, 2004
  Sonikusan Jun 17, 2004
Has anyone explored this option? Might the powervr be capable of addressing more vram than the default?

 antime Jun 17, 2004
The Naomi board has double the video memory of the Dreamcast, so that part isn't a problem. The rest? Finding that out sounds like a good summer project for you!

 Sonikusan Jun 17, 2004
You're giving me evil thoughts.....

 M3d10n Jun 17, 2004
So, after you spend several hours soldering extra RAM into the DC's PowerVR without destroying it, what's next? Do you expect your games to look any better? Well, they won't, because no developer would add bigger texture packs "just in case someone happens to solder extra RAM to their DCs".

You could make a kickass game with higher res textures. That only runs in your DC, that is. But I hardly doubt you'd get something with graphics on par with even the first Sonic Adventure, since noone of the freely avaliable DC dev tools I've seen so far offer fast performance access to the 3D features.

You'd gain more by trying to overclock the PVR, or the SH4. Maybe that'd lessen the slowdown in some games.

 Daniel Eriksson Sep 25, 2004
Still, If some kind of addition pack would be done, they could be sold. The DC got an expansion port right? Still, it would require someone to create a game using it. Nah, the hardware is good enough. Its probably better to create a better Dev-Tool if you want to see better looking games...

 Daniel Eriksson Sep 25, 2004
Btw, wasnt some kind of addition for DC in planning? Perhaps it was only rumors...

 Alexvrb Sep 26, 2004
They had some projects on the burner, Sega has always built things that they never release. I don't know about anything designed to add power, though.

Adding more main memory would probably be more useful for homebrew, and yes you could do it. But it'd be a monumental PITA, so practically nobody would do it even with a detailed guide. Most people don't even mod their DCs, let alone rip it apart, solder in extra memory, and modify the BIOS. So coders probably wouldn't care. Overclocking could give you a more immediate benefit for all existing software, but again not many people are going to do it.

 ExCyber Sep 26, 2004

  
	
	

		
		

			and modify the BIOS


I've seen no reason to believe that the BIOS has to be modified to allow more RAM or VRAM. I'm pretty sure that's a myth.

 Krelian Sep 28, 2004
Well look at it like this:

The basic in/out sys of a PC is designed to expand it's hardware's addresses to accomodate more memory. But it has a canopy. Then over time sometimes there are firmware upgrades that allow more to be addressed.

Without that revision it won't address the superfluous memory.

Now the hardware of a console rarely changes (unless it's an atrocity made of off-the-shelf computer parts a la Xbox), why would Sega design said in/out sys to address more memory than the console was manufactured with?

Now I'm not saying that theory is correct but it does make sense.

~Krelian

 antime Sep 28, 2004
Because they used the same parts in the arcade version which has double the amount of video memory compared to the Dreamcast? Your description of PC hardware is also rubbish, but that's another issue.

 Alexvrb Sep 28, 2004
I'm not defending my original statement. I got it from someplace else, and it is likely that it was the misinterpretation of facts by someone else down the road. But anyway, I highly doubt the BIOS is the same that of the Naomi, even if everything else is the same but memory and source of data (which even in units with GD-ROMs isn't directly from the GD on demand... loads to cheap volatile memory on power up IIRC).

 antime Sep 28, 2004

  
	
	

		
		

			Originally posted by Alexvrb@Sep 28, 2004 @ 09:20 AM



But anyway, I highly doubt the BIOS is the same that of the Naomi


As ExCyber said, does it matter?

 ExCyber Sep 28, 2004

  
	
	

		
		

			why would Sega design said in/out sys to address more memory than the console was manufactured with?


You've got the question backwards. Standard bus and memory designs are naturally compatible with expansion up to the point where the bus runs out of addresses, and the SH-4 and PVR2 have built-in RAM interfaces (designed by Hitachi and Videologic, not Sega) that are known to support more RAM than what is in Dreamcast. The question is "Why would Sega request a special set of crippled chips just for Dreamcast instead of making chips that could be used in Dreamcast, Naomi and future systems?".


  
	
	

		
		

			Now I'm not saying that theory is correct but it does make sense.


And I'm saying that it doesn't make sense. When you get right down to it, the BIOS is just a program whose primary purpose is to get the hardware into a sane state and get another program loaded into RAM. Once that second program is loaded, the BIOS no longer really has any control over what happens. For its part, a chip usually doesn't care how much RAM is hooked up to it, it just does what its told, and if the RAM you told it to write to doesn't exist, well, that's your problem for telling it to do something stupid.

 Alexvrb Sep 29, 2004

  
	
	

		
		

			Originally posted by antime@Sep 28, 2004 @ 02:03 AM



As ExCyber said, does it matter?




[post=119898]Quoted post[/post]

I never said it mattered, only that it is.

 Virgil Aug 26, 2005

  
	
	

		
		

			Originally posted by Krelian@Tue, 2004-09-28 @ 12:03 PM



Well look at it like this:



The basic in/out sys of a PC is designed to expand it's hardware's addresses to accomodate more memory. But it has a canopy. Then over time sometimes there are firmware upgrades that allow more to be addressed.



Without that revision it won't address the superfluous memory.



Now the hardware of a console rarely changes (unless it's an atrocity made of off-the-shelf computer parts a la Xbox), why would Sega design said in/out sys to address more memory than the console was manufactured with?



Now I'm not saying that theory is correct but it does make sense.



~Krelian




[post=119885]Quoted post[/post]


The Dreamcast is just as outsourced as the Xbox. Sega just used hardware desighned for something like the dreamcast. Hitachi has info on thier site, as does Power VR.