N64 Expansion Pak - Internal DRAM PCBA's

Discussion in 'Nintendo Game Development' started by Gerry_MAN, Oct 19, 2017.

  1. Gerry_MAN

    Gerry_MAN N64 Hardware Fanatic

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    Hi Folks,

    Working on some N64 Dev hardware repair...

    [​IMG]


    I'm needing to source some official Nintendo brand DRAM. So I decided on using official N64 Expansion PAK's which seemed like a perfect solution. So, with that said I'm trying to gather info and HI-Res Photos for all the various versions of "N64 Expansion PAK's". Primarily Photos of the PCBA's revealing both the PCBA model numbers and also the DRAM model numbers.

    Shown below is the official Nintendo Brand Expansion PAK model# NUS-007

    [​IMG]


    So these Expansion PAK Modules are the DRAM modules that insert into the top of the N64 console.

    [​IMG]
    [​IMG]

    Remove Default JUMPER PAK using accessory tool...

    [​IMG]

    Insert N64 4MByte Expansion PAK...
    [​IMG]

    These are used to increase the system RAM from the default internal 4 MBytes...up to 8 MBytes which is used for specific N64 game titles and also for all 64DD games..... and is also a requirement for 64DD development.


    Now the N64 console arrives with a redundant terminator module inside the consoles expansion socket. This BUS terminator module is called the "N64 Jumper PAK" and simply allows the console to function correctly with the default internal 4MBytes of DRAM.

    These Jumper Pak's simply house some surface mount Resistor arrays for BUS Termination.
    As shown further below:

    [​IMG]

    [​IMG] [​IMG]
    PCBA Model# NUS-RTC-xx (There were a few different revisions.)



    Now going back to the DRAM Expansion PAK's, from what I have researched the official Nintendo Brand Expansion PAK's have a PCBA model# NUS-RMC-xx and usually house a single DRAM Chip model# RDRAM36-NUS As shown below:

    [​IMG]

    For those of you that are interested I have provided some Datasheet download links for a couple of Equivalent DRAM components. These are the 9-Bit databus DRAM devices...so not as common as 8-bit but are used by the N64 & 64DD. Datasheet Links below: (One from NEC and one from LG)

    NEC Brand:
    http://www.digital-circuitry.com/IM...GI_Ultra64/DRAM/Datasheets/DSA2IH00127808.pdf

    LG Brand:
    http://www.digital-circuitry.com/IM...Ultra64/DRAM/Datasheets/LGS/DSA2IH0087323.pdf


    Now I have also read about certain 3rd Party Expansion Packs that will house a PCB that can accommodate (x2) DRAM chips. Usually two RDRAM18-NUS to make up the 4MBytes. However sometimes they will just install a single RDRAM36-NUS and leave the second chip footprint un-populated. As shown with this "YOBO" brand Expansion PAK PCBA.

    [​IMG]



    Now...I have not actually seen a photo of a particular N64 Expansion PAK that does in fact house (x2) DRAM chips within it.....does anyone have a Photo of one ?

    I'm hoping everyone here could give me a hand if possible to collect some more info and Photos....?
    For those of you that do have an N64 Expansion PAK...official or not....if you could pop it open and take some Hi-Res Photos of the internal PCB with the DRAM chip... both front and back...and also include the Model number of the Expansion PAK that it belong to. Then post it here in the Thread for the archive...that would be appreciated.

    I'm hoping someone here may have photos of one that actually has (x2) RDRAM Chips inside. As I have not been able to identify the PAK model number that does use two chips.

    Anyhow,
    I would appreciate the help.
    Thanks in advance.

    Cheers!
    -Gerry
     
  2. rso

    rso °

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    Wow, funky form factor on those ICs. Never seen that one before.
    I have two official paks, apparently identical to yours - NUS-007 w/ NUS-RMC-10 PCBs.
     

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  3. Gerry_MAN

    Gerry_MAN N64 Hardware Fanatic

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    Yeah...they are definitely unique.

    As indicated in the datasheets....
    the top 4 corner pins are strictly there for mechanical support.
    They serve no purpose in terms of Logic functionality.

    Thanks for posting those pics.... :cool:
    Cheers!
    -Gerry
     
  4. Gerry_MAN

    Gerry_MAN N64 Hardware Fanatic

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    Same form factor is used for the internal DRAM within the N64 console:

    [​IMG]

    Which makes sense....
    As the Expansion PAK's are simply meant to add memory to this databus. :p

    -Gerry
     
  5. Rocky

    Rocky N64 Fanatic

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    Here are three official ram packs! The one with the blue blackground has a copyright of 2000.

    All are NUS-007.
     

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    Last edited: Oct 19, 2017
  6. Gerry_MAN

    Gerry_MAN N64 Hardware Fanatic

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    Cool... Thanks guys!! :)

    I'm still hoping someone out there will have one that houses (x2) DRAM chips... :D

    -Gerry
     
  7. Gerry_MAN

    Gerry_MAN N64 Hardware Fanatic

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    Hi All,

    So I found this pic in a customer review section on an Amazon page selling N64 Expansion Packs.
    https://www.amazon.com/Nintendo-64-Expansion-Pak/product-reviews/B00000INR2

    This Lo-res image still points towards a cheap knockoff. The PCBA has no model# and the user review indicated that the DRAM Chip serial numbers were too blurry to actually read. He assumes this was done intentionally by the scammers. I guess it is possible that Nintendo always did use a single RDRAM36-NUS chip.... for all of their 4MByte Expansion PAK's........??

    [​IMG]

    We'll have to wait and see if someone else comes forward with a better hi-res photo that actually shows a Nintendo PCB model number and (x2) official Nintendo DRAM chips.

    The waiting Game continues...

    Cheers!
    -Gerry
     
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  8. rso

    rso °

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    (attached the higher res photo from that AZN listing for posterity)

    I don't see why Nintendo would move away from a single chip solution. For cost saving reasons? Nah. They may have changed the chip, but I believe it's very unlikely that going with that a second chip would ever end up being cheaper... Chances are you'll only see the two-chip PCBs in third party products (and fakes) whose producers may not have had access to higher-capacity chips, or who had no qualms about cutting it awfully close wrt signal quality (due to the longer traces on the larger pcb) or whatever.
     

    Attached Files:

  9. Gerry_MAN

    Gerry_MAN N64 Hardware Fanatic

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    Thanks for posting that hi-Res version.

    To this point I've only seen the RDRAM18-NUS (2MByte) DRAM chips on the N64 console PCBA. I had high hopes that there might be an another source for these. The plan was to use them as replacement components.

    I wanted to try and stay as authentic as possible... and use the same 2MByte chips that this Dev board has. However, using a couple of these RDRAM36-NUS 4MByte ones, is totally doable. I may have no choice.

    I'd rather do that than sacrifice a couple of N64 consoles...... just for the DRAM.
    I don't think I could bring myself to do that. LOL... :p

    Cheers!
    -Gerry
     
  10. marshallh

    marshallh N64 Coder

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    Is the indy board not working?

    Nintendo branded and licensed expansion paks always use 36mbit chips.

    N64 motherboards from NUS-CPU01 to 05 use two 18mbit chips, 06 to 09 use 36mbit.

    3rd party and knockoff paks almost always use two 18mbit chips.

    Early versions of the Ultra64 GIO board used NEC branded 18mbit chips, while later ones had the Nintendo branding applied (they are the exact same chip made by NEC though).

    For example, the Aleck64 uses both brandings to get 8mbyte:

    [​IMG]
     
  11. Gerry_MAN

    Gerry_MAN N64 Hardware Fanatic

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    Hi Marshall,

    Wow......Fantastic info here.
    The knowledge you share is always appreciated.
    So thanks for posting that.

    Yes the Ultra64 board I am reworking for a friend. It was functional at one point before, but then suddenly stopped working. It was sent to a professional SGI repair house. Additional DRAM had been added to the board, however the overall repair was unsuccessful.

    It arrived here in my Lab not too long ago. There was trace damage around the DRAM and a few other minor issues. I was trying to source some of the official Nintendo DRAM components to use as replacements for when performing the board Re-work. However, as you have pointed out that the NEC and Nintendo DRAM's are electronically the same component. With this new info I don't think I'll bother replacing the NEC components. I'll simply perform the needed board rework.

    Once I get things working, I'll follow up with a devoted thread.

    Thanks for the info and Photos Marshall.
    Again, it's much appreciated.

    Cheers!
    -Gerry
     

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