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Dreamcast Dreamcast double memory mod is now possible! 32MB Ram!

Anthony817

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So the unthinkable has been made possible! We actually have a guy in the community who goes by the name of tsowell who has worked out all of the kinks with adding double memory such as is possible with other similar systems like the original Xbox. The great part about this mod is it is VERY cheap to perform if you have the skills and parts are only a few dollars, for the memory and a bios chip. No cannibalizing of an expensive Naomi Arcade system! The modder said that it cost him 12.66 USD for two IS42S32800J-6TLs. Bios is seperate.

The short and sweet of it is that you have to add all new memory chips, 2, 16mb modulals.

original_sdram.jpg


You replace these old chips with the new ones below.

finished.jpg


Overall this seems to be a straightforward mod. I hope people offer an upgrade service for this mod!

You can find complete instructions here!

 

FamilyGuy

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That's nice, but only homebrew will be able to use the extra ram no? I think the DC libraries were written with a fixed amount of RAM in mind.
 
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truemaster

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well thats nice but the dc games are created having 16mb in mind. so in what matter this will help. im not snobing the thing i just try to undreastand
 

Anthony817

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OG Xbox retail games have been patched to enable double the memory with the ram upgrade for that system, so why wouldn't it also be possible here? I believe there is an app called Ram Delimiter for OG Xbox that does just that. At least on the Xbox side, it is down to just 2 lines of hex code needing to be altered. So no, this shouldn't be limited to only homebrew, if the brilliant minds in the Xbox community can figure it out, why can't we too?
 
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Arcadia

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Is this 100% compatible with existing games?
 

Anthony817

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It should play all games normally. Theoretically if you were to make games have improvements with this mod they would need to be patched. It is my understanding the games on Xbox didn't just stop working with the double ram mod, they just had to be patched to take advantage of it.
 

FamilyGuy

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OG Xbox retail games have been patched to enable double the memory with the ram upgrade for that system, so why wouldn't it also be possible here? I believe there is an app called Ram Delimiter for OG Xbox that does just that. At least on the Xbox side, it is down to just 2 lines of hex code needing to be altered. So no, this shouldn't be limited to only homebrew, if the brilliant minds in the Xbox community can figure it out, why can't we too?
I'm under the impression that the Xbox has more of a modern OS allocating memory in the background (it's basically a PC). Whereas the DC has the games running almost on bare metal and having complete control over memory themselves; in that case it would be much harder to add support for that extra RAM on DC compared to Xbox.

But I don't know much about Xbox or the exact way DC allocates memory and I could be completely wrong, don't quote me on that.
 

Wesker

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Maybe it's possible to clear TOM JAM & EARL 3 with this mod.

Heroes of Might and Magic III may also be fully playable thanks to this.

What about the prospect of making Naomi and Atomiswave games to work on Dreamcast thanks to this?
 
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Anthony817

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IIRC Naomi has more video memory as well, so maybe and maybe not with certain games? But yes, on the OG Xbox the same was done with the Xbox based Sega Chihiro arcade machine games getting them working on double RAM modded Xbox systems. So theoretically I would say it could be possible. Especially with the faster read times of the GDEMU this may be more of a possibility.
 

darcagn

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dcemulation.org
I'm under the impression that the Xbox has more of a modern OS allocating memory in the background (it's basically a PC). Whereas the DC has the games running almost on bare metal and having complete control over memory themselves; in that case it would be much harder to add support for that extra RAM on DC compared to Xbox.

But I don't know much about Xbox or the exact way DC allocates memory and I could be completely wrong, don't quote me on that.

This was what I was thinking as well, this is likely to be a lot bigger of a challenge than for the Xbox, especially for Katana games.
However, the games that need it the most are Windows CE games, and I think it would be a lot easier to mod Windows CE.

What about the prospect of making Naomi and Atomiswave games to work on Dreamcast thanks to this?

Naomi/Atomiswave have twice the VRAM and quadruple the sound RAM, so I wouldn't hold my breath for those.
 

Anthony817

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That is a good point, maybe focusing on the Windows CE element here could be the key to unlocking better performance at LEAST with those games? We all know how much overhead the WinCE games require, thus hurting overall game performance. And since Windows CE is already an OS people would maybe be more familiar with it could hopefully be possible to edit a few bytes here and there?
 

Bad_Ad84

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My thoughts is that it will help dreamshell and its iso loader. Can also cut down the install by buying a bios chip with the patch bios already flashed.

Cool mod!
 

MetalliC

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What about the prospect of making Naomi and Atomiswave games to work on Dreamcast thanks to this?
almost completely useless:

Atomiswave - have exact same tech specs as regular Dreamcast => we have no AW->DC ports because no one wants to waste his time on it, not because lack of DC's RAM or some other tech problems.

Naomi - have 2x video RAM and 4x sound RAM than regular DC => it is useless to have only main RAM extended.
 
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Wombat

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Does anyone know if there a way to check the currently dumped NAOMI/Atomiswave roms to see how much video/sound ram they use? Perhaps there are some (lighter) games that never use more then lets say a stock Dreamcast on those elements, in that case those titles would be a great starting point to experiment with.
 
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accel99

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almost completely useless:

Atomiswave - have exact same tech specs as regular Dreamcast => we have no AW->DC ports because no one wants to waste his time on it, not because lack of DC's RAM or some other tech problems.

Naomi - have 2x video RAM and 4x sound RAM than regular DC => it is useless to have only main RAM extended.

So... Atomiswave conversions is actually possible? Didn't expect that because I thought it had double vram? Someone was working on it but I guess he never made it far. Well at least is good to know it's doable.

Besides have double ram/vram I thought Naomi had a different revision GPU with double fillrate? If so does atomiswave have the same revision?
 

accel99

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no, to my knowledge all the HOLLY-based devices uses same chip/revision.
you probably confused with Naomi 2, which have 2x HOLLY working in parallel and thus produce double fillrate.

Ah thanks for clearing that up. There is multiple sources of misinformation then claiming that the Naomi 1 had double fillrate of dreamcast. Off the top of my head one source was the emulator beetledc/flycast that claimed that and Sega retro. Good to know main parts of the hardware in identical then.

Libretro beetledc