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Latitude CS memory upgrade - The Final Word

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Latitude CS memory upgrade - The Final Word

  • Hey folks!

    I've been searching and reading various threads about the memory upgrade options on my Latitude CS R and there seems to be a lot of conflicting and incomplete information. I would like this thread to be the Final Word on memory upgrades for this laptop so I (and everyone else) knows what is possible. I am also assuming everyone reading this is comfortable with voiding their warrantee since we'll be trying to use non-Dell approved memory configurations.

    Here's the specification:

    We know the Latitude CS R has two memory SODIMMs, one in the user accessible panel underneath the laptop and one under the keyboard. I've read in this forum that the SODIMM under the keyboard is socketed just like the one underneath so it could be replaced as well. The specifications say that the memory is SDRAM, speed is 66MHz, voltage is 3.3V, timing is CL2 or CL3. The specifications do not say anything about ECC/parity or non-parity -- lets assume non-parity. The specification also don't say anything about the chip configuration.

    My first concern is that it seems hard to find SODIMMs larger than 128MB that are running at 66MHz. Has anyone used PC100 or PC133 in their Latitude?

    Ok, lets look at the user accessible socket first. I've read on this forum that people have successfully had a 256MB SODIMM working. Could anyone who has this working report your experience? Please include the exact specs on the SODIMM you're using (speed, timing, chip configuration) as well as the amount of memory you have under the keyboard, and the total amount of memory the laptop can see, and your BIOS version.

    Now on to the forbidden socket under the keyboard. Has anyone tried replacing the SODIMM in this socket? If so, please report your experiences. I've seen this socket mentioned on the forum, but nobody has said they tried replacing the chip.

    As soon as someone says which 256MB module works, I will order one and try it out myself. I will also try changing the SODIMM under the keyboard with my existing chip.

    Thanks for any help!!
  • Your in luck.... I have found a 256mb module for your laptop for only $70.00 with free shipping over at silicon mountain.  Just click on this LINK and use the selector and select dell, and a window will pop up, it may take a few seconds for it to load, then drop down the next menu and select Latitude CS R, and that will direct you to the memory that you need for your laptop.... however, remember, to reach the max of memory for your computer, is that you need to have the one module of 256mb, and one moduel of 64mb which equals to 320mb of ram...  you cannot have 128mb module in with the 256mb module, nor can you install two modules of 256mb...

    heres how you can install the memory,

    Installing Memory Modules

    Your system's factory-installed memory can range from 64 megabytes (MB) to a system maximum of 320 MB. Depending on the memory already installed, you may be able to increase memory by installing a 32-, 64-, or 128-MB synchronous dynamic random-access memory (SDRAM) small-outline dual-inline memory modules (SODIMMs) in the memory upgrade socket. The maximum achievable memory for your system depends on the system's original memory configuration.

     NOTE: If necessary, print these instructions for reference before proceeding.

    NOTICE: Dell Latitude CS portable computers support only SDRAM SODIMMs. Extended-data out (EDO) memory modules are not supported.

    To upgrade computer memory, you can install or replace a memory module through the memory module cover on the underside of the computer. To prepare the computer for the removal or installation of a memory module, perform the following steps.

    NOTICE: Ground yourself by touching an unpainted metal surface of a connector on the back of the computer. While you work, periodically touch the connector to dissipate any static electricity that might harm internal components.

    Turn off the computer and any attached devices.
    Do not install memory modules while the computer is in suspend, standby, or suspend-to-disk mode.

    If the computer is docked, undock it.
    Disconnect the computer and peripherals from their electrical outlets to reduce the potential for personal injury or shock.
    Disconnect any telephone or telecommunication lines from the computer.
    Remove the battery from the battery bay. 
    To remove or install a memory module, perform the following steps.

    NOTICE: To avoid scratching the top of the computer, make sure that your work surface is clean. You may want to put down a protective mat before turning over the computer.

    Close the display, turn the computer upside down, and remove the memory module cover (see Figure 2).

    Use a #1 Phillips-head screwdriver to remove the two screws securing the memory module cover. When the memory module cover pops up slightly, lift it up and remove it to expose the memory socket or installed memory module beneath.

    Figure 2. Removing the Memory Module Cover


    If you are replacing a memory module, remove the old one.

    Carefully spread apart the inner metal tabs of the memory module socket just far enough for the memory module to disengage from the socket (it should pop up slightly). Then lift the memory module away from the socket (see Figure 3).

    Figure 3. Removing a Memory Module

     1 Memory module
    2 Metal tabs (2)


    Ground yourself and unpack the new memory module from the upgrade kit.
    Install the new memory module in the socket (see Figure 4).

    Figure 4. Installing a Memory Module


    Memory modules are keyed, or designed to fit into their sockets in only one direction. The socket is notched so that the memory module can be seated only one way as follows:

    Align the memory module’s edge connector with the slot in the center of the memory module socket.
    With the module at a 45-degree angle, press the memory module’s edge connector firmly into the memory module socket.
    Pivot the memory module down until it clicks into place.
    If you do not hear a click as each end of the memory module snaps into the metal tabs, remove the memory module and reinstall it.

    Replace the memory module cover as follows:
    Set the memory module cover into the opening, aligning the tabs on one side with the slots in the computer cover.

    Press the cover down and replace the screws you removed in step 1.

    NOTICE: After installation, if the memory module cover does not fit or is difficult to close, you may have installed the memory module improperly. Remove the module and reinstall it. Do not force the memory module cover to close because you may damage your computer. 

    Reconnect your computer and devices to their electrical outlets and turn them on.
    As the computer boots, it detects the presence of additional memory and automatically updates the system configuration information.

    In one of the following ways, verify that the System Memory option in the System Setup program reflects the newly installed memory:
    Click the Start button, point to Settings, click Control Panel, and click the System icon. The amount of memory installed in the computer is displayed in the lower-right corner of the General tab window.

    In the System Setup program, the System Memory option appears in the lower-right corner of pages 1, 2, and 4.
    If the system memory total is incorrect, the memory module(s) may not be installed properly. Repeat preparatory steps 1 through 5 and removal and installation steps 1 through 7 until the memory total is correct.

    Run the System Memory test of the Dell Diagnostics to confirm that all installed memory modules are operating correctly.
    Use the Suspend-to-Disk utility to update the S2D partition on your hard-disk drive. The S2D partition stores system data while the computer is in S2D mode.

    Message Edited by buffbison on 01-29-2003 03:51 PM

  • Actually, you can do much better over at Crucial:

    A 256MB SODIMM for $45.99. This is PC133 and the configuration is 32MB x 64. This is what I would get if I knew it worked. What is the configuration of the memory you linked to? Have you tried it yourself?

  • Yes, i agree that crucial is much cheaper, however, i suggested silicon mountain b/c they had the 256mb module for your system, whereas crucial never did, which you've stated that you wanted in your previous post....but if you don't want the 256mb module, then go for crucial memory.. 

    Message Edited by buffbison on 01-29-2003 04:23 PM

  • Ok, I tore my laptop open to see what the story is with the memory under the keyboard. First of all, to get the keyboard off, start by sticking a flat head screwdriver through the three tab holes in the back of the laptop (right above the serial/dock/parallel ports). This will pop off the plastic panel covering the numlock/capslock/scrolllock lights. Under this panel you will find two screws to remove the keyboard, and under the keyboard you will see a metal cover with 7 screws. Remove all the screws and you will reveal the hidden SODIMM slot (and the CPU as well).

    The SODIMM type in this slot was exactly the same as the SODIMM in the user-accessible slot. It has the following numbers on it:




    (Mitsubishi Logo)

    The first number tells me that this is PC100 / CL=3 memory. The next number is the Mitsubishi part number -- similar part numbers can be found at:

    This part number isn't on this list, but it is close enough to guess that it is a 128MB module, configuration is 16M x 64, 3.3v, non-parity.

    Now I wonder how close of a match do I have to get if I want to put 256MB in the bottom slot? Will 384MB work? How about 512MB?

    To be continued...


  • Well im not sure if 384mb will work though....heres intel's website for the chipset, but it doesn't give a clear indication what the max ram is.....  but dell and silicon mountain and crucial both say 320mb...  which is 256 + 64mb modules

    you shouldn't be installing hardware into your comptuer unless you know for sure what and how much your computer can handle....i've tried searching through the net but nothing came up i rather see you be safe to stick with 320mb total memory than installing more than that and risking damaging your computer...

    Message Edited by buffbison on 01-29-2003 11:06 PM

  • The 320mb is based on 128mb in the upgrade slot and a 192mb module on the M'board. The use of 256mb in the upgrade slot is w/o Dell's blessing. The one my church owns operates fine with 2-128mb modules. I've never seen the 192mb module even listed for sale, so it must be super rare. When I purchased this unit for the church, it came with a 256mb PC100 Module in the upgrade slot and I did not look specifically at the one on the m'board as I did not want to dissemble the machine but it was a 128mb; total was 384mb & it seemed to operate without problems. Since I was not keeping it to use myself, I sold the 256mb and replaced it with a 128mb PC100; that is what it still has today. PC66 modules can be had in 128mb size, but if you want 256mb PC100 or 133 are it. Some of the PC133 are of a form and/or density  that is not compatible with the older models, so to be on the safe side, I would stick to PC100 if the side bus speed is PC66. 

    Message Edited by leduke30 on 02-24-2003 03:16 PM

  • Hi Steve,

    Although I have said this before on other threads, I'll say my bit again here too!
    I have a Latitude CS R400XT, has a PII 400 CPU, the same system as yours I believe.

    I have sucessfully upgraded it to 384mb, completely recognised and usable. The people that say the max is 320mb (192mb + 128mb) are either:

    1. Dell forum mods (they have to stick by Dell's official specs)
    2. People who stuck to Dell's official specs because they didn't want to try it out
    3. People who have just read the info provided by Dell.

    I can assure you that the system accepts at least 384mb.

    I have the A13 bios, when I took my computer apart I found the internal slot had a PC100 128mb SODIMM stick in it (even though it runs at PC66, PC100 can run at a lower speed). I put a PC100 256mb stick in the expansion slot at the bottom and it worked fine. As the "official" word is that the bottom slot only accepts up to a 192mb stick, I was half-expecting it to only count the first 192mb, losing 64mb's worth, but this wasn't the case. 384mb fully operational.

    The only question I have now is, could the internal slot take a 256mb stick instead, to make 512mb? :)


    P.S. buffbison is just trying to earn commission from you buying memory through his links.
  • Pipes,

    What you have said can be true, it certainly is in your case as you have had success. I am not sure what makes the same make and model and same bios revisions so different but I know of many that have not had the success that you have. I know many that can only run up to 256mb on the CS R and the CSx. 320mb is tough to get to because of how rare 192 mb sodimms are.  It seems as if it is a hit and miss deal between similar machines and not a for certain thing.

    256mb is more then ample in my opinion for those running the CS R or CSx, even with XP. I think the big thing is the hdd, people should look at running a 5400 hdd as the 4200 is a real slug.

    Just my opinion......

  • Pipes,

    Even after upgrading the bios to A13 as you suggest, my  CSx H500 will not recognize the 256MB module.  What can you suggest?

  • Examine the module.  There should be 16 chips on it - eight per side.  If there are only eight of them, on a single side, that's the problem - the RAM is high density and will not work.


  • I know I'm "responding" to a discussion that stopped long ago, but thought I would add something that might be useful to others as I have just upgraded 2 Lattitude CS R units at work.

    First, I found that using the newest BIOS (A13) allows the computer to recognize 512 MB RAM. I installed 2 256MB Crucial PC100 SODIMMS into the units (one under the keyboard using the instructions in this thread and one in the more accessible memory slot under the cover) and at the same time I upgraded the HDD to a 20 GB unit (Seagate Momentus ST92011A 20GB Ultra ATA/100 5400RPM Mobile Hard Drive from ; I did not need a bigger drive on this unit- strictly work related apps (MS Office) and remote access to work) and installed W2K sp4, went through all the winupdates and the unit really sings- OK- not as fast as a P4, but for a grand total of $330 and a couple of hours, a really great very portable unit. Not a desktop replacement, but it works really well.

    steve rose

    Message Edited by SteveMRose on 10-02-2003 12:51 PM

    Message Edited by SteveMRose on 10-02-2003 12:55 PM

  • Dell made the CSx to use a special 192mb Module as an option in the board slot and 128mb in the upgrade user-accessible slot. Some folks have used 256mb  in that upgrade slot and got away with it, but Dell will tell you that is not supported and definitely not a good idea. I used to think that Special 192mb Module was a myth, until 2 showed up on ebay recently.
  • Thanks- I understand Dell does not approve or think it is a good idea, but I have been unable to get them to articulate what the problem would be other than "it is not approved or recommended." There must be some technical reason, but I have yet to find someone who can say what it is.

    steve rose

  • Thanks for adding that Steve, that's very interesting info.

    I've currently got 128mb stick under the keyboard and 256mb in the expansion, making 384mb. I always wondered if the other slot would also accept 256mb to make 512mb. Thanks :)
    I've also got a 20Gb drive in mine, an IBM Travelstar.

    I've recently acquired a CSX motherboard, so I'll be swapping out my CS R 400 one soon, and putting the csx board in, then adding an 850/700 mhz cpu to it :)