Yokemate of Keyboards
Posts: 2795 from 2006/3/21
From: Northern Calif...
Maybe I don't get it because no one from bplan has stated that it can't be done! You seem to know what you are writing about, so I will give you a lot of credit, but you are not an engineer from bplan.
Neko wrote:
Quote:
Read the MPC5200B manual, SDRAM controller section. The pads on the board - I believe - connect 16-bit lines from each module, to the 32-bit controller (this is the standard way to do it on the MPC5200B) and there are two chip selects available for SDRAM..
The way I see it (and I have the schematics), adding 4 modules means connecting 4x 8-bit lines to the 32-bit controller and using the second chip select. The traces simply do not support this configuration. You need to add resistors etc. in places you can't get to and somehow escape a pin that's not escaped in the design.
This is the first time I have seen anyone write about the details of why adding more memory is physically impossible due to missing traces to the memory controller, so thanks for pointing out exactly what you think the problem is. But answer this: If the pcb was designed for only two chips of RAM as you say, why did they add the RAM solder pads to the bottom of it? What are the traces from the solder pads at the bottom of the EFIKA connected to? I mean if they intentionally left out the memory traces, why not leave out the RAM chip solder pads too?
You are probably right in how you have read the manual and schematics, but it sure would be more believable if an engineer from bplan would confirm what you have just written.
Not that I want to piss you off or anything like that, but I will continue trying to contact someone at bplan to clear up exactly what is possible and what is not possible with the EFIKA pcbs that have already been produced and sold.
Maybe as you imply, it might be possible to increase the RAM by removing the 128mb of existing RAM and replace it with 256mb if the correct chips can be found. That would be better than doing nothing.
As for what bplan will and will not do, unless you have information directly from them, other than their statement that they want a minimum number of 300 - 1000 units to produce EFIKAs with 512mb of RAM, I would rather hear directly from them.
Again I ask, why am I being met with such negativity and now hostility. When did it become a crime to ask questions and try to find better answers to problems? A simple answer of "no it can't be done and here is why" would have been sufficient. When the why is not clear or complete, then people should expect it to be questioned.
I am starting to feel like the bad guy just for asking questions and wanting to have more memory on my EFIKA. Give me a break!
MorphOS - The best Next Gen Amiga choice.
