RAM Disk device since Swiss v0.6r1534

[Borg Number One]

Hi.

since Swiss v0.6r1534 there is a new kind of a selectable device: "RAM DISK".

What is the purpose and/or how can this be used?

Are there any plans or planned projects for a real GameCube RAM-Disk-Extension/-Expansion hardware through the GameCube's ARAM Port (GameCube's parallel Hi-Speed Port)?
A GameCube RAM-Disk-Expansion maybe in the same solderless way like flippydrive?

This would be helpfully to have more RAM (or more available swapped/swapping memory) for Linux on GameCube.

[Papy.G]

This has been discussed somewhere, but memory can be expanded, hardware-wise, via the opera DS expansion RAM cart or maybe any other third-party one in the GBPlayer.
Technically, a RamDisk can take place into the internal machine's memory, as is was possible on the Atari ST or pre-X system Macintoshes, to only tell about what I personally used, while I don't know how it can be used in games, where the Ram can often be used to its maximum.

[Extrems]

ARAM can be expanded by replacing the internal 16 MiB SDR SDRAM chip with a 32 MiB one, or by placing a 2/4/8/16/32 MiB chip on the Hi Speed Port.

The RAM disk device creates a exFAT formatted disk on the Hi Speed Port expansion. There is currently no purpose for it, but could be used as a patch device in the future.

The Game Boy Player and its accessories cannot be used for this purpose.

[Borg Number One]

Hi.

the default "ARAM-DOL" SDR SDRAM chip is a: "NEC D4891281G5".
Is there a successor chip or pin and feature compatible version (maybe from another manufacturer)?

Where to get NEC D4891281G5 datasheet PDFs from?

What is the name of the 32MB version?

Are there any documented web sites or blogs where you can read and see about such a memory expansion modifiction (SDR SDRAM chip replacement)?

Are there any wiring diagrams for connecting a 32MB SDR SDRAM with the GameCube's High Speed port?

[Papy.G]

…

Did somebody ever successfully performed such a mod?
Does the internal memory mod still allow the use of the GBPlayer?
Will it be of any use to get closer to Triforce titles support?
Would 32MB on the high speed port result in masking overlapping memory space, or would it really add the whole 32MB more?

…

If a bigger size chip is possible in the familly, may I guess NEC D4892561G5…
For the external option, we may be able to find compatible substitutes, without the pin disposition constraints.

[Extrems]

Did somebody ever successfully performed such a mod?

We haven't yet been successful with the internal mod due to an initialization problem.

Does the internal memory mod still allow the use of the GBPlayer?

It would.

Will it be of any use to get closer to Triforce titles support?

No.

Would 32MB on the high speed port result in masking overlapping memory space, or would it really add the whole 32MB more?

The SoC supports 2 banks of 32 MiB, for 64 MiB in total.

[Papy.G]

The SoC supports 2 banks of 32 MiB, for 64 MiB in total.

So we can go up to 32MB internal and 32MB at the same time?
What is the minimum size needed to support the bigger patches?

[webhdx]

64MiB of total ARAM memory with larger onboard chip + external expansion via Hi Speed Port.

[Extrems]

So we can go up to 32MB internal and 32MB at the same time?
What is the minimum size needed to support the bigger patches?

32 MiB should cover everything reasonable (i.e. not the factory/service discs) and there isn't really any point going smaller.

[Borg Number One]

Hi webhdx,

Could you describe more details about your GameCube ARAM expansion mod?
Is there a project page (maybe in future on GitHub?) and/or a list of used components and wiring diagrams?

[Papy.G]

32 MiB should cover everything reasonable (i.e. not the factory/service discs) and there isn't really any point going smaller.

Does the GBPlayer's memory adressing allocation allow enough area for an integrated ARAM expansion in it? Would it be possible then to use it?

Well, in YAGCD, I found that:
"HSP devices seem to be accessable through the ARAM interface with offsets beyond 16MB"
So the GBPlayer may host a 16MB ARAM extension taking place in the first memory adressing area?

[Extrems]

The 2 banks are addressed contiguously no matter their size. The Game Boy Player is 16 MiB of expansion ARAM.

[webhdx]

Hi webhdx,

Could you describe more details about your GameCube ARAM expansion mod?
Is there a project page (maybe in future on GitHub?) and/or a list of used components and wiring diagrams?

I haven't published anything yet because it didn't work reliably. For some reason the module is only detected half of the time. Maybe it's related to the initial configuration done in BS1. I need to update PicoBoot to replace BS1 and check ARAM expansion again.

[Borg Number One]

Would a multi-channel logic analyzer (either connected to the GameCubes's Parallel / ARAM port or connected to the ARAM-DOL pins) be helpful to find out the reason why the module is only detected half the time?

[Papy.G]

The 2 banks are addressed contiguously no matter their size. The Game Boy Player is 16 MiB of expansion ARAM.

Yes, so we may be able to add 16MB internally in the GBPlayer to get to the maximum 32MB of the dedicated bank.
I know a little about memory adress/data buses mux, still, I can't figure out how we can adress this much RAM through a connector with so few pins, can you please point me to somewhere the workings are explained, as I can't seem to be able to find such information in the YAGCD?

[Extrems]

36 pins is few? Well, it's only 8-bit wide instead of 16-bit.

[Papy.G]

I'm sorry to ask so many "dumb" questions, I think I have read all those information from somewhere and I would be able to find all the answers to those by myself if only I would remember where it was.

I see "SDRam" in the YAGCD, so would we just be able to wire a 32MB SDRAM PC 100 module to the expansion port?

I also see 13 adress lines, 2 bank adress lines, 8 multiplexed A/D lines, that doesn't make the total 25 lines needed to adress 32MB in an SDR RAM architecture.

Is the GBPlayer 16MB adress space duplicated in the resting 16MB adressing space, or does it auto-disables when adressing this other part?