Naomi Net Dimm 256 mb to 512 mb Upgrade

[DCrosby]

I've been searching and there have been some posts that state that you don't need to change anything on the net-dim to upgrade it from 256 to 512, I don't know if different net-dims have different cuircuit designs, from the pictures I've seen this doesn't seem to be the case. But I have yet to get a concrete answer as to what you have to do to accomplish this.

I have tried 3 different (2 Identical, one that came with the net dimm) 256mb sticks, and each works fine in the far right slot, which I presume is slot 1, and then if I use only slot 2 or add another stick to slot 2, I get the dreaded Error 32 Dimm Memory is not Enough.

And so I'm asking what settings or methodology am I missing to get this to work, I have a 512mb single chip on order, to try and make that work, hoping that it'll recognize the single module.

This is with Both (Doesn't work)


This is with one stick in the first slot (Works)


This is with it in only the second slot (No dice)

 

[DCrosby]

Oh and the naomi and net-dimm seem to be healthy.

 

[DCrosby]

So I can confirm after today that a single 512mb DIMM module can/does work.
The Specific module from what I've been told is not specifically relevant as long as it follows these guidelines:

512MB PC133 133MHZ SDRAM
168PIN HIGH DENSITY
Non-ECC Memory​

I'm also fairly certain that my second slot is just not functioning properly, as no ram, Samsung or other that fits into that slot that works on the outside slot, and does work on the inside one. So I opted to go for a single 512 mb Module and that seemed to work for me (Ran Melty Blood with Multibios on Japanese Mode), you results may vary... but I'm trying to add this to the discussion as I couldn't find anything concrete on Dip/Jumper values, which I think is a dead end.

 

[Tyson1911]

you have to clean the ram slot or try to push the ram slot pins a little closer together. the original dimm rams are a bit wider than the standard pc133

 

[DCrosby]

you have to clean the ram slot or try to push the ram slot pins a little closer together. the original dimm rams are a bit wider than the standard pc133

That's good to leave here for posterity, could also be cold solder joints on the slot... Who knows.. if you have 1 slot working with 256, I would suggest you update it with 512, as that seemed to work for me. But your results may vary...
And if you want to bend pins on your net-dim, then do your thing, who knows how rare / expensive both the ram and the net dim are in the future... may be worth the risk.

 

[bobbydilley]

Just out of interest, what’s your reason for upgrading the ram in the NetDimm?

 

[Tyson1911]

Just out of interest, what’s your reason for upgrading the ram in the NetDimm?

There are some games that require 512 mb of storage to start the game since they are large or greater than 256mb, which is the standard that Naomi dimms bring, for example Rhythm Tengoku

 

[bobbydilley]

Ah of course! Sorry I was trying to rack my brains to work out which Naomi 2 game required 512, but forgot to consider Naomi 1 games! Thanks for the detailed instructions

 

[djsheep]

Beach Spikers, Virtua Fighter 4 and Virtua Striker 3 being the three notable ones to play with 512MB.

 

[twistedsymphony]

There is a whole thread about compatible memory sticks here: https://www.arcade-projects.com/threads/those-of-you-with-512mb-and-1gb-dimm-boards.1093/

 

[Vanark]

My dimm has 512 mb in one slot and my net dimm 256 and 256 mb. If I installed 512 from dimm to net dimm, its mean error 32

 

[LittleMegaGamer]

Beach Spikers, Virtua Fighter 4 and Virtua Striker 3 being the three notable ones to play with 512MB.

I have been enjoying my WiPi setup lately... My Dimm Board is 256mb (Firmware rev 3.17) and I played Beach Spikers and Virtua Fighter 4 with no issue, but Virtua Striker 3 froze during the demo mode (just after booting) or during the gameplay. Is it because it needs 512mb? Why it boots anyway with 215mb?
(To be fair, the same thing happens with Chaos Field, maybe my roms are corrupted?)

 

[twistedsymphony]

100% of the game data is transferred into the DIMM RAM before the game even attempts to boot. so if you don't have enough RAM then the game wont even load because it can't finish the transfer.

your problem is something else.

start with checking voltages, you should have a solid 3.3V on the DIMM board itself. you might also want to do a RAM test to ensure that that the Stick in your DIMM Board is good.

 

[LittleMegaGamer]

100% of the game data is transferred into the DIMM RAM before the game even attempts to boot. so if you don't have enough RAM then the game wont even load because it can't finish the transfer.

your problem is something else.

start with checking voltages, you should have a solid 3.3V on the DIMM board itself. you might also want to do a RAM test to ensure that that the Stick in your DIMM Board is good.

Ram test was good in my last checking, I could do it again.
I didn’t check the voltage, I will try to do it although I am using an ATX psu.
This issue happens mostly with Virtua Striker 3 so far…
I will do more test and report back.. is it ok run the voltage test from the back of the Naomi JST connector?

 

[twistedsymphony]

is it ok run the voltage test from the back of the Naomi JST connector?

that wont give you an accurate reading.

the voltage will drop from the input connector to DIMM board because of all of the connectors it has to pass-through internally to get there, that's why it's recommended you adjust voltage based on the location where it's being used, not where it enters the PCB.

of course if you're using an ATX PSU you can't adjust it, best you can do if you find out it's too low is buy proper PSU.

 

[LittleMegaGamer]

that wont give you an accurate reading.

Like you said, it is not accurate, but that is what I got:
3.16v during booting and demo mode,
3.13v during the gameplay
(on both 3.3v pins)

Perhaps it is just a coincidence, but I had two long sessions of VS3 of about one hour each with not issue. I have also played a few other games with no issue like mentioned previously.

Tieding the the netdimm board to the mobo by using zip ties is the only change made. I did it in order to improve the video signal which is pretty stable now. I had to do that because my Naomi is working vertically on the timber board of the cab and the netdimm board was getting loose and giving a "noisy signal". It looks great now.

Of course, If I move the multimeter test leads the voltage change going up and down... but that is what I got by leaving the test leads in a stable position.

In relation to VS3 I noticed the frame rate drop sometimes (in rarley occasions). Is it normal? Will make any difference adding a 215mb bank of ram

of course if you're using an ATX PSU you can't adjust it, best you can do if you find out it's too low is buy proper PSU.

Anyway, I will stay with with this PSU for now, hopefully it will keep working well like is doing at the moment... but I will think about to replace it if I will get further annoying issue.
I have installed a switched 3 gang socket inside the cab and I wouldn't install the original Sun PSU just because I will need to install an isolation tranformer for it. I get the benefict of the multisocket just for devices running at 220-240v (I have the stereo amp and the atx psu for now). Do you know any alternative to the Sun PSU which allow to adjust the 3.3 voltage? Like a good Mean Well model that could work at 240v?

 

[twistedsymphony]

Perhaps it is just a coincidence, but I had two long sessions of VS3 of about one hour each with not issue. I have also played a few other games with no issue like mentioned previously.

given you're at 3.1V you're probably seeing stability issues due to low voltage at the DIMM board. (I'd guess you're around 2.8 or 2.9V inside the DIMM board.

sorry I don't have any 240V PSU recommendations for you, it's not something I've ever researched.

 

[LittleMegaGamer]

given you're at 3.1V you're probably seeing stability issues due to low voltage at the DIMM board. (I'd guess you're around 2.8 or 2.9V inside the DIMM board.

yep, I think so too at this point

sorry I don't have any 240V PSU recommendations for you, it's not something I've ever researched.

No problem, I will take a look to the Mean Well catalog, they usually come with a varied inout voltage.
Also, I have a spare PAL Dreamcast PSU, but it won't have an adj 3.3v though.
Thanks anyway