32MB RAM upgrade

[mrneo240]

naomi has dual pvr

[|darc|]

naomi has dual pvr

The original NAOMI is a single PVR? NAOMI 2 has dual PVR.
However, NAOMI does have twice the VRAM as the Dreamcast and quadruple the sound RAM.
I would not expect to be running NAOMI stuff on Dreamcast anytime soon.

On the other hand, Atomiswave and Dreamcast already have pretty much the same hardware.

This is going to be most useful for development (extra memory for debugging functions), emulators (able to load larger ROMs), and homebrew ports of games/software with heavier RAM requirements. With a little work it might be possible to get stuff like Half-Life and HMM3 to see the extra RAM.

[tsowell]

For those attempting to do this, I have uploaded an updated DreamShell CDI image with nearly 50 different BIOS images in a variety of flavors

Thanks for putting that together! I added a link to it in my post.

I hadn't heard of Dreamboot until now, but I'm going to try it out in the next week or so.

[|darc|]

I now have a 32MB RAM Dreamcast! I actually got around to getting this done before pulling out for vacation. I had to take a risk in doing a piggyback BIOS install instead of a triple BIOS since my PCBs haven't been made yet -- if any of the BIOS images with 32MB patches didn't work, the DC would have been bricked and I would have had to do some soldering to get things working again.

Luckily, everything I tested WORKS!* I gave my bootROM a good working out today.
(*By "works" I mean the Dreamcast boots up and I am able to launch Crazy Taxi or DreamShell.... I didn't do super extensive testing for each BIOS)

Code: Select all

1.004 vanilla                  UNTESTED, PROBABLY WORKS
1.01c vanilla                  UNTESTED, PROBABLY WORKS
1.01d vanilla                  WORKS
1.01d w/ region free patch ("link83")         WORKS      
1.01d w/ region free patch alt intro ("link83")      WORKS
1.01d Treamcast                  UNTESTED
1.022 ("no mil-CD BIOS")            NOT INCLUDED ON DISC, UNTESTED
jc 1.300 regular intro               WORKS
jc 1.310 regular intro               WORKS
jc 1.310 alt intro               WORKS
jc 1.032 regular intro               WORKS
jc 1.032 alt intro               WORKS
dreamboot 1.0.0                  WORKS
dreamboot 1.0.0 No GD-ROM            UNTESTED, SHOULD WORK
dreamboot 1.0.1                  WORKS
dreamboot 1.0.1 No GD-ROM            UNTESTED, SHOULD WORK
dreamboot 1.0.2                  WORKS
dreamboot 1.0.2 No GD-ROM            UNTESTED, SHOULD WORK
dreamboot 1.1.0                  WORKS
dreamboot 1.1.0 No GD-ROM            UNTESTED, SHOULD WORK
dreamshell boot_loader regular intro         WORKS            
dreamshell boot_loader regular intro No GD-ROM      UNTESTED, SHOULD WORK
dreamshell boot_loader alt intro         WORKS
dreamshell boot_loader alt intro No GD-ROM      UNTESTED, SHOULD WORK
dreamshell sd_loader_with.bios            WORKS

[tsowell]

I now have a 32MB RAM Dreamcast!

Awesome, I'm glad it works! Welcome to the club!

[|darc|]

Uh oh! Sonic Adventure crashes when loading and Phantasy Star Online v2 crashes when going to the FMV!!! Crap.
Good news is that it is possible to put the pins on a DPDT switch and turn the mod on and off.


Can you verify the above bugs happen to you as well, tsowell? Perhaps my RAM is not soldered well enough, I don't have enough time to reflow it or anything right now.

[Ian Micheal]

I dont see how the extra ram could break games when they cant see it ?
are the ram chips the same speed ? finding out why it would do that
could you not take the real ram off 2 dreamcasts matching ram chips and use that for the mod?

[tsowell]

Uh oh! Sonic Adventure crashes when loading and Phantasy Star Online v2 crashes when going to the FMV!!! Crap.
Good news is that it is possible to put the pins on a DPDT switch and turn the mod on and off.


Can you verify the above bugs happen to you as well, tsowell? Perhaps my RAM is not soldered well enough, I don't have enough time to reflow it or anything right now.

I get the same bugs! So at least your soldering is probably fine. Attached is a little memory test program you can use if you want to verify the entire address space.

I wonder what these games are doing to break it.

[Ian Micheal]

Pretty intriguing what there doing since they cant see the ram how why would it have an effect is pretty puzzling to me does this mean the first 16 meg is has corruption doubt the added ram is making those games crash nothing in the code i would think that can check for something that was never there..

[ChristinaDreamcustDC]

If anyone is tech savvy enough, it would be a good excuse to put out a patch for Sonic Adventure and PSO for added ram support/fix crashing issue. I'm sure it would be an interesting combination with the 60 FPS patches. The original Xbox has had some homebrew RAM patches for official games to fix slowdown and increase FPS, so it shouldn't be impossible for the Dreamcast? For Sonic Adventure the 60 FPS patches increase the frame rate but on a real console if the game gets too taxing it slows down. If added RAM support is ever hacked in the community could distribute the games with 60 FPS/added Ram patches.

I''m sure that the 60 FPS versions of Sonic Advance and Phantasy Star would crash at the same points, but if anyone would like to try them I would be interested. Maybe they would crash differently/earlier?

The crashing has me remembering old SNES games that would check the cartridge for features that it shouldn't have, like save batteries, checksums, or storage space.

tsowell, can you give examples of a couple games that start and play fine, at least for a little bit? Have there been any noticeable changes in other games, including crashing, glitches, etc?