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Hardware Hacking Data Storage

What Can You Do with Old Memory? 121

Posted by Cliff from the make-a-mobile-out-of-'em dept.
An anonymous reader asks: "I've just upgraded the RAM in a bunch of laptops and have several gigs of spare PC2700 memory sitting in a desk drawer. I also have another project which requires a large amount of low latency temporary storage. So, I figured this would be a great place to employ a dedicated hardware ramdisk but I am having a problem finding one that doesn't cost an arm and a leg, or preferably an empty unit that works with my spare memory. I have found many discussion forums which talk about building an IDE ramdisk out of commodity RAM, but have not found anyone that has actually done it. Has anyone on Slashdot found such a holy grail? Is anyone currently working on such a project? Do any of you have the engineering experience and interest to design such a device?" What novel purposes have you done with spare RAM that you haven't had the heart to throw away?
"Before you ask, my primary server is maxed out on RAM at 2 gigs, and I am still filling up my 1 gig software ramdisk when I end up with an unusually large data set that needs processing. Yes, I am aware that an IDE device would be limited by the IDE interface for throughput, but I am more concerned with latency then throughput, and IDE is common and simple enough to connect to any of my desktop servers without the need for an add in card."
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What Can You Do with Old Memory? More

What Can You Do with Old Memory?

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  • Caching disk controller (Score:2, Interesting)

    by Anonymous Coward

    Buy a caching RAID controller and fill it up with 1GB of memory

  • One time, (Score:1, Interesting)

    by Anonymous Coward
    I saw this keychgain a guy had made out of a 256K SIMM. I thought that was pretty cool.

    • Re:One time, (Score:2, Interesting)

      by zcat_NZ ( 267672 )
      It was pretty cool for a while.

      After about a week all the chip capacitors started breaking off. After a few months the chips thesmelves were wearing at the corners and eventually came off. And for the last three years I've had a bare circuitboard on my keychain. Now I have an anodized aluminium penguin which will hopefully be a little more robust.

      • I have a 720K (!) SIMM on my keychain, and before putting it there, i just put a little superglue under the chips. Looks pretty cool and after 4 years all the simms are still there.
        • I had 2MB on a keychain but I tend to be forgetful and leave my keys in my pockets. This leads to keys in the washing machine. Washing machines don't like ram...
          • I don't think it's the washing machine that has anything about not liking the RAM. More likely, it's the RAM that doesn't like the washing machine. :-)
      • The capacitors on my 1MB SIMM aren't visible (maybe not even there?), so all I can see is the chips (which have started to wear down on the corners). The contacts are wearing down, though.
    • You wouldn't be in the Grand Rapids, Michigan area, would you? I made and sold eight of those for 50 cents each as a kid.
    • I've gone through a few of those. Though they're hard to find these days, the old 30-pin is best. 72+ pin sticks are just to big for normal pockets.

    • I wear a 486dx2 on mine. I left it on the board, cut around it, and made a hole in the board to put a keyring through.

      It works.

  • What do I do with old memory? (Score:3, Funny)

    by Pan T. Hose ( 707794 ) on Saturday January 22, 2005 @08:12PM (#11444649) Homepage Journal
    I don't remember...

  • flooring? (Score:3, Funny)

    by jjirvin ( 612615 ) <kb0cht@arrl.net> on Saturday January 22, 2005 @08:12PM (#11444653) Homepage
    get ahold of Tommy at This Old House and see if they'll do a geek show in which the put down a parquet memory floor /jji

  • laptop ram? (Score:5, Insightful)

    by Goeland86 ( 741690 ) <goeland86 AT gmail DOT com> on Saturday January 22, 2005 @08:12PM (#11444654) Homepage
    man, if you don't wanna throw it away, sell it on ebay, and then with the money you make buy something adequate for it. I'll buy some of that ram myself, if you have a 512 meg bar.
    Seriously, that ram is worth cash, get the cash, then buy what you've been looking at that was out of your budget before.
  • All my old 72pin and 36 pin RAM gets converted to keychains. Then, when all the little IC's fall off, I just grab another one!

    Of course, they're starting to get a little harder to find, so eventually I'll have to change - maybe to old laptop memory.

    A SDRAM might make a nice bookmark, though. ;)

  • Extra controller memory (Score:2, Informative)

    by Squant ( 652554 )
    The older SIMM modules make excellent modules to add a big chunk of memory to your controller/processor/DSP/FPGA for all kinds of things.

    Or you can just use a paintstripper and get the chips off, and incorporate them in your project.
    The left over boards you can use as guides in your tech books.

    Interfacing can be tough sometime, here an AVR example:
    http://www.myplace.nu/avr/dram/index.htm [myplace.nu]

    Just google for your favorite controller type with the word DRAM.

  • ramdisk pci card? (Score:3, Informative)

    by way2trivial ( 601132 ) on Saturday January 22, 2005 @08:20PM (#11444689) Homepage Journal
    they require identical chips- and usually aint cheap.

  • Take it to you local computer surplus store (Score:4, Insightful)

    by HotNeedleOfInquiry ( 598897 ) on Saturday January 22, 2005 @08:23PM (#11444701)
    And just give it to them. Next time you need something, you'll be surprised at how generous they are. I've taken my old but serviceable stuff to the local surplus store for years. I've also received stuff I've needed for projects for pennies on the dollar.
  • "What can you do with old memory?"

    Well if you're a manufacturer of PC100 128 or 256 sticks you can charge twice what they were going for a year or two ago.

  • Donate it to someone who needs it! (Score:4, Insightful)

    by jcbphi ( 235355 ) on Saturday January 22, 2005 @08:35PM (#11444755) Homepage
    Its not so novel, but I'm sure there are plenty of schools, community centers, etc. around where you live that could always use spare hardware. A lot of the boxes these organizations receive are stripped down, and having extra sticks of RAM is very useful for them.

    My grandmother uses a computer built from donated parts that a local group provides for the elderly, and she's now able to talk with her 4 generations of family over email (which is pretty well spread around the world now). There are probably tax breaks for you too, but in general donating unused hardware to those that will use it is a Good Thing.

    • Re:Donate it to someone who needs it! (Score:4, Informative)

      by jbn-o ( 555068 ) <mail@digitalcitizen.info> on Saturday January 22, 2005 @08:48PM (#11444815) Homepage

      I concur, please do consider donating the memory. I worked for a local place [prairienet.org] that refurbished donated computers and used them for a community networking initiative which provided poor people with:

      • a gentle introduction to using a computer (many hours of hands-on use with an instructor who can answer questions on-the-spot),
      • a computer system (including all the hardware and software they needed to do real tasks),
      • and a dialup account at the ISP operated by the organization.

      All of this was provided at no cost to the recipient. As I understand the financing, the place is run on a combination of grant money, selling dialup accounts and hosting, and donations. After building and testing a bunch of low-end machines used for these classes, my work there ended. It was a good karma job with good people working there and I would work there again if the need arose.

      As a former technician there, I would have been grateful to receive donated RAM for what is today considered old. I'm sure someone's machine would have used it (or some machine that will soon be donated there would use it).

    • In addition, there are organizations with the aim of providing IT technologies to 3rd world countries, that need this kind of donation.

      A Pentium 2 with 64 MB of memory could be top of the tech-tree for some people in African countries.
  • Sell it on eBay.

    I have a drawer full of 72-PIN SIMMs I dont know what to do with. They might be a grand total of 256MB or so... some simms have 2MB ram.

    What should I do with those?

  • Suggestions (Score:4, Interesting)

    by MBCook ( 132727 ) <foobarsoft@foobarsoft.com> on Saturday January 22, 2005 @08:54PM (#11444840) Homepage
    Well, my best suggestion would be to sell the stuff (eBay or a local shop) and use the money towards what you want.

    That said, if you want to do it yourself, there is one thing I think would work reasonably. Now the cost of doing this might not be low. I don't know. Here we go:

    There are tons of PLCs and ASICs and stuff on the 'net with lots of free code for 'em. There is free code to interface with memory modules so your chip could talk to ram and use it in a project. There is ALSO free code to talk to a hard drive (make a IDE interface) for your MP3 player or whatever. Now it seems that with all that documentation, it shouldn't be too hard to make a simple little state machine that translates incomming IDE requests to specific RAM addresses (a simple mapping from C/H/S or LBA to address should do it), fetch (or write) that data, and return it over the IDE interface (which you would have to make "backwards" from most on the web because you want to BE the HD, not talk to it).

    I would think you could get some good speed out of that, shouldn't be hard to make it faster than a simple hard drive. The biggest problem would be that it would need to be partitioned and formatted at startup, but that could be easily done in a script (and it's not like it would take long if you skip bad block scans and such).

    Someone may have already done this if you look hard enough.

    So that's my suggestion. Would be a cool little project, and it shouldn't be hard to put as much RAM in as you want, you just have to multiplex it. The biggest problem would be refreshing all that RAM if you multiplex it. But those are problems for you to solve. Now if you DO do this, PLEASE post results (or at least expiraments) to /., as I'd love to see what you come up with (even if you go with another solution all together).

  • how to buid it (Score:2, Interesting)

    by ryanelm ( 787453 ) *
    download the infosheet on the ram you have from the company that made it or a company that makes equivalent. it will they'll you the timing neccesary to read, write and refresh the memory, something like bring 'cas' pin high for x nano-seconds then write the first y bits of the address then bring 'ras' high and write the rest of the address then read from or write to the data pins. Then get a picmicro controller and write a program to controll the memory and talk ide, load it on the micro-controller, then w

    • Re:how to buid it (Score:3, Informative)

      by ColaMan ( 37550 )
      Wait, is someone pulling numbers out of their ass?

      +- $25 total time: 3hrs - 2months depending on expiriance

      Except for the fact that your PIC probably has 16 or so data lines, and you need 100 or so addressable lines to talk nicely to PC2700 ram. Oh, and don't forget the 40 lines you need to talk to the IDE interface.
      So , that $25 just ballooned out to a coupla hundred when you factor in some glue logic and a few fpga devices of sufficent capacity. And 3 hours might be a little on the low side there for
      • not to flame or anything but where do you get the idea that you need fpgas and glue logic to make two pic controllers talk to eachother? and there _are_ pic chips with like 80 i/o pins going for about 10 bucks.
    • I've looked into doing this, and after doing a cost analysis, I'ved concluded that making a *useful* pci/ide ramdrive is not worth the effort.

      First off, it simply is not worth it to make an IDE or PCI based solid state disk with only a few megabytes. Why not simply buy more ram and create a RAM disk in windows or whatever instead? But even that will not give you much performance enhancement, perhaps speed up the start time of apps launched from the disk.

      Familiar with Verilog/VHDL? I hope so, you'll probab
      • i aggree , i have built a few things out of old dram , but the time & effort it would take to throw this together outweighs the near free costs of the materials. this would only be easy for someone who had done both ide and memory controlling before and had the chips, programmers etc. around. BTW. a 'ram refresher system' would be part of the controller already due to the extremely short time ram stays charged for (think milliseconds) so all that would be required to keep the data is a battery source p
      • I am not wanting to start anything. I just want to point out that the poster says he has maxed the mother board out already, and needs more temporary low latency storage. So adding more ram no matter how cheap will not get them anywhere.

    • Not quite that easy (Score:2, Interesting)

      by Anonymous Coward
      I make IDE drives for a living, and it's not quite as easy as you make it sound, sadly.

      The part you will find hard, going this route, is drive recognition.

      When writing a host, you only have to support minimal drive handshaking and then you can start throwing read and writes.

      Writing a drive, you usually have to support a metric tonne of informational commands before a host will recognise you as a valid drive - and even then you're looking at odd behaviour from different BIOS revisions and operating system
  • Sounds like you need an IDE adaptor designed to work as a slave, not as a master: i.e., the same interface that IDE hard disks have. Unfortunately I have no idea if such a thing exists. Probably not.

    However, you could do this with Firewire, because there isn't a master/slave distinction with Firewire. You could buy a cheap-and-nasty computer, put all your memory into it, hook it up to your server and use it as a (very big) solid-state hard disk. Firewire's about the same speed as IDE.

    Unfortunately, your

    • The IDE controller isn't the master, the words master and slave are used to distinguish from up to two IDE devices (harddisk, CD/DVD drives, etc.) on one IDE controller. The IDE controller itself doesn't have a name.

      IDE controller
      |||||||||||||| (40 pins flatcable)
      master device
      ||||||||||||||
      slave device

      I'm not entirely sure, but IIRC, the master device determines the maximum throughput speed and/or determines which device is active when.
      • The IDE controller isn't the master, the words master and slave are used to distinguish from up to two IDE devices

        Sorry, I didn't mean that (it's too late, I've just played through the Darwinia demo [which rules] and I need caffeine). I mean that the interface has a master end (the computer) and a slave end (the drive). USB works the same way. Firewire and SCSI, however, are peer-to-peer in that there's the same interface on all devices, regardless of what they do.

        (You can plug multiple computers in on

    • Unfortunately, your slave computer would need software to make it act like a hard disk, and while I'm sure such a thing exists, I don't know where..

      Make a ramdisk under linux, share it using Samba/NFS, and connect the two computers together using gig ethernet.
  • I have lots of old memories of my ex that I'd like to get rid of. Any of you masochists want them?
  • .... I had a good joke lined up but I'll can it for now. :) Anyway, I go out of my way to find BAD RAM. Why?I've had a few motherboards come in that have falsly reported known bad RAM (run through hardware and software based RAM testing equipment) as good RAM, which caused all kinds of install time goodness. Now, I keep known bad sticks to test in various machines which seem to be a little "off". It's also wise to keep spare power supplies, CPUs, hard drives and the like as well. If for any other purpose th
  • I've always knocked the chips off and use the circuit board for a box cutter that you don't slice yourself on.

    Also, you can go on a plane with them.

    Well, that's what *I* do.

    --Xan

  • Use tmpfs (Score:4, Interesting)

    by DocSnyder ( 10755 ) on Saturday January 22, 2005 @09:40PM (#11445041)
    tmpfs consists of "file system cache" without a physical file system, stored in shared memory and pageable to swap space. Lacking real I/O, it runs like crazy and makes the slowest boxes fly. Export the file system via NFS or Samba/CIFS and use it for very fast network storage.

    # mount -t tmpfs -o size=$muchbutlessthenvirtualmemory tmpfs /work
    # mount -t tmpfs -o size=384M,nr_inodes=384k tmpfs /work

    tmpfs paged out to swap space on a real hard disk is still much faster then ext2/ext3/reiserfs/xfs/jfs/... on a hard disk partition. Without swap space, don't fill them up beyond your physical memory size minus about 32 MB for the operating system, or set the size limit to such a value.

    The only disadvantage of tmpfs is the complete loss of its content after unmounting it. And of course you'll have to fill it after mounting it.

  • Making a dedicated RAM disk. (Score:4, Interesting)

    by Yaztromo ( 655250 ) on Saturday January 22, 2005 @10:36PM (#11445331) Homepage Journal

    Here's my suggestion. Get an older system which has a motherboard which accepts the memory you have -- preferrably one with lots of slots. Install as much RAM into it as you can, along with a NIC.

    Install Linux or FreeBSD on it (if it has a hard drive -- if not put together a bootable diskette), and create a big RAM disk -- as big as you can. Set-up either NFS or Samba to allow network access to the RAM drive.

    And if you're going to use it for storing anything other than /tmp, put the system on a UPS. Nothing worse than losing a whole disks worth of data due to a minor brownout.

    Yaz.

  • Same Question for Old CPUs (Score:4, Funny)

    by pipingguy ( 566974 ) on Saturday January 22, 2005 @11:19PM (#11445534)

    Once I upgrade the two AMD MP 1800+ processors from my current computer what do I do with them? I'm not an eBay person and I'd hate to just give them away to a local shop. Since these matched CPUs (supposedly) need specific, fairly rare motherboards and RAM, I figure that donating them to a local school or whatever might be a waste.

  • ramdrive controllers (Score:3, Informative)

    by winterdrake ( 823887 ) on Saturday January 22, 2005 @11:30PM (#11445593)
    http://www.hyperos2002.com/07042003/products.htm [hyperos2002.com]

    HyperOs HyperDrive III, 16GB capacity, ATA100, rather pricey.

    http://www.cenatek.com/ [cenatek.com]

    Cenatek Rocket Drive, various product versions, PCI instead.
  • I don't mean to minimize your question, but I had to laugh when you described PC2700 as "old"... I've been digging through my closets looking for my plastic bag full of old '486-era SIMMs - perhaps 1-4 meg each? - to send to Central America, where a guy I know helps run a kindergarten. Import duties on anything remotely modern are prohibitive, so he's struggling to keep early-90s PCs online running educational software to teach kids how to read and etc. That's what I thought of when I saw this article hea
    • He have any use for a bag full (probably 24 sticks or so) of 30-pin 1MB SIMMs??? I was going to take a previous poster's idea and make keychains out of them for sale on eBay, but if your friend can use them for something... well, useful, he can have 'em. They've been sitting in this static bag for umpteen years now.
      • Yes he could use the RAM; I can't find a way to Email you privately here - please contact me at this temp address: bonsoirfp(at)yahoo(dot)com, and thanks in advance!

  • FreeCycle (Score:4, Informative)

    by Solder Fumes ( 797270 ) on Sunday January 23, 2005 @12:12AM (#11445803)
    Freecycle [freecycle.org] is a neat community giveaway-fest run through localized Yahoo groups. I live in a town of 100,000 and the Freecycle group has 700 members. I've given away old monitors, tables, couches, even a car. I got a nice little dual-proc server. Right now I'm paring down what I have for an upcoming move, but it's a great place to get free stuff. I see bedframes, dressers, computers, bikes, clothes, it makes dumpster-diving obsolete.
  • Super-charge that old HPLJ2 compatible laser printer you're still using - turn it into a 36MB beast!
  • I need more RAM, but don't have enough money to buy it. I am currently with a 256Mb system, isn't that awful? Help a little red-haired brazilian girl to get a better computer: donate your RAM :)
  • We have a local non-profit in Portland called FreeGeek. They accept donations of old hardware, refurbish it, and get computers into the hands of other non-profit and worthy causes.

    Check out www.freegeek.org. Maybe you can FedEx your old memory to them :)
  • ...put it in an unmarked box, leave it out on your front door, and post your address? It'll be gone in a matter of hours.
  • PC2700? Isn't that what the brand new Mac Mini uses? :)
  • Cenatek pci ram disks [cenatek.com]

    BitMicro [bitmicro.com]

    M-Systems [m-systems.com]

    You could probably find one for normal sdram, but to find a device that goes from 40/80pin ide to laptop SO-DIMMS is going to be a challenge.
  • I"ve had the same 'problem' in the past. Since most ram chips have a little hole in the corner, I've used the chips as cool keychains. I try to do this with dead memory, but if the memory has no value to you, and you need a keychain fob....

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