Fattening your Slug is adding more RAM to the slug.
*WARNING Doing this will DEFINITELY VOID YOUR WARRANTY.*
There, you have been warned...
Ah.. I see you are still here...
The first thing you have to do is open the case (preferably in a somewhat static free area)
Follow the directions to open the case.
2 methods of fattening: replace the two existing 8Mx16 RAM chips with 2 equal sized but bigger RAM chips or add 2 RAM chips of the existing size "piggy backed" (or do both for maximum ram).
RAM used must be added in identical pairs and if two banks are being used, must also be the same for both banks. Obviously each chip must be at least 16MB.
The following table shows the required number of chips for a given memory configuration:
If you are using 4 chips then the /CS pin (pin 19) of the 2 "piggy backed" chips should be connected together to the unconnected pin on PR12.
A good source of chips are PC133 SDRAM modules. 128 Mbit chips can be obtained from a 64 MB module with 4 chips or a 128 MB module with 8 chips; 256 Mbit chips from a 128 MB module with 4 chips or a 256 MB module with 8 chips; 512 Mbit chips from a 256 MB module with 4 chips (I don't know if this exists) or a 512 MB module with 8 chips. They are much cheaper than buying the chips individually (or free if you have some lying around).
Note: Most 256 MB modules use 32Mx8 chips instead of 16Mx16. Double check the chips before you buy or install. The safest option is to look for 128 MB modules with 4 chips.
Comment from Joschi: I just bought a 256MB PC133 module consisting of 4 512Mbit 32Mx16 chips at www.fscomputer.de. Found this by googling for "32Mx16" AND "PC133".
This job requires a steady hand and a very small soldering iron tip (<1mm)
The RAM chips can be de-soldered with 1mm solder wick and a 30 watt iron (any more and you will potentially damage the board). I would recommend using flux as well; a flux pen works best. That serves to clean the oxidation off both the tip and the pins, and allows maximal heat flow to the pins.
Once you have them de-soldered you may need to pry them off the board as they may be glued.
If you don't want to save the existing RAM you can cut the leads at the body and more easily unsolder the chip.
Photos are posted at the NSLU2-Linux Yahoo Group (http://groups.yahoo.com/group/nslu2-linux).
Modifications to RedBoot and the Linux kernel are also necessary to enable the usage of the extra RAM. Without these modifications you will only be able to use 32MB. See the details of the software side boot loader modifications
Without changing the bootloader, I was able to access the lower 64MB by recompiling the kernel alone. I changed the memory parameter of the kernel command line to "mem=64MB@0x000000". I am not sure if this will also work on 64MB and 256MB upgrades. [ ERROR? ... on 128MB and 256MB upgrades ?? ]
To access all the installed memory, you will need to change the bootloader and/or modify the kernel. I have used APEX bootloader and it works as expected.
If you are using Openslug, then changing the kernel command line ("mem=xxx") in APEX is all that is needed. The last time I checked, Unslung needs a kernel recompile because the command line parameters are hardcoded.
Comments on a 128MB upgrade (2x512Mbit chips): --Micirio
After I changed the bootloader to APEX:
Fazit: I could not use the 64MB without using APEX
Comments on a 256MB upgrade (4x512Mbit chips): --Rob Lockhart
Comments on a 128MB upgrade (2x512Mbit chips): --caiacoa
-- Paul Brandt, April 29, 2008
view · edit · print · history · Last edited by Mattia.
Based on work by Paul Brandt, fcarolo, hjames, Charles Santos, caiacoa, Rob Lockhart, chacko, Phil Endecott, Chacko, JustRob, TPP, Micirio, plugwash, kinsa, joschi, rwhitby, ka6sox, and tman.
Originally by ka6sox.
Page last modified on June 27, 2008, at 12:04 PM