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Most CF Cards Fail DMA Transfers

Posted by kdawson on from the it's-all-in-the-controller dept.

Anomalyst writes "In his quest to create an open source video camera, Andrey Filippov of elphel.com has determined that most Compact Flash devices, although claiming to be DMA capable, do not perform Direct Memory Access transfers correctly. This means successful movement of data to and from the device takes much more time with DMA disabled." The culprit appears to be the controller chip packaged with most of the CF cards Filippov tried. We last visited Elphel and their work on open source digital cameras in 2002. Filippov gave a Tech Talk at Google last year.

140 comments

  1. frosty piss by Anonymous Coward · · Score: -1, Offtopic

    enjoy!

    This comment is GPLv3 licensed.

  2. Good work by Anonymous Coward · · Score: -1, Offtopic

    Maybe one day I'll see a camera with a bog standard USB connector that doesn't need a specific driver just to see the camera's contents as a drive?

    1. Re:Good work by Creepy+Crawler · · Score: 1

      I guess FTP isnt good enough for you?

      --
    2. Re:Good work by dnwq · · Score: 2, Insightful

      I haven't seen a digital camera that requires separate drivers in ages. My own camera is detected as a USB hard drive - XP, Vista, and Ubuntu alike - and it's more than four years old.

    3. Re:Good work by argent · · Score: 1

      Just about every camera I've looked at recently has a bog standard mini-USB connector and didn't require custom software to see the camera's contents as a drive, at least not with OSX.

    4. Re:Good work by LanceUppercut · · Score: -1, Offtopic

      I hope you do understand that what you are talking about has no relation to the problem described in the original article whatsoever...

    5. Re:Good work by baxissimo · · Score: 3, Informative

      I think the OP was tricked into thinking that the crappy software that came with the camera was actually required to use the camera. The instructions that come with these cameras do tend to make it sound like installing the software is a mandatory step, and fail to mention that you can just access the pictures using Explorer. I guess they want to get their little bit of AdWare on your system. Or maybe they really are worried that Aunt Tillie doesn't know how to use Explorer.

    6. Re:Good work by Anonymous Coward · · Score: 0

      He's obviously just talking out of his ass and probably doesn't even own a digital camera.

      I have 5 cameras, 2 are Samsung, 2 are Sony and 1 is a Canon. The oldest one is from around 2000 and the newest one is from this year. All of them use a standard USB connector and none of them require a driver to work under Windows XP or Ubuntu. Just plug one in and it pops up as another drive.

    7. Re:Good work by Goaway · · Score: 1

      I hope you do understand that posts on slashdot can actually be replies to other posts, not just to the article itself.

    8. Re:Good work by Anonymous Coward · · Score: 0

      Wow, your OSX do that?, i wonder how the rest of the world cope without this intuitive and well thought operating system.

    9. Re:Good work by Anonymous Coward · · Score: -1, Troll

      Hello,
      OP here. You are deluded. Try plugging a Canon S3 into a computer that never had any Canon hardware on it. Perhaps your ass is so slack from pulling such stupidities out of it so often.

      1) You need the correct USB cable because the camera tries to act as a host (so it can drive a printer). Thing is, all these cables look exactly the same.
      2) You need to install Canon's sheisse to access the camera.

      Try it. I did. Did you? Or is your turd cutter doing all the typing again?

    10. Re:Good work by Anonymous Coward · · Score: 0

      Where on the planet are you? It's the opposite in my case. Almost every camera has some sort of combined A/V USB connector. Perhaps you need to look closer or at more brands? Maybe I have more money than you and can look at more cameras?

    11. Re:Good work by Steve+Max · · Score: 1

      I have an S2, not an S3. I've never installed any Canon software on any of my computers. I can plug it to any computer, and any PTP-compatible software can grab the pictures, using any MiniUSB cable.

      Try it. DigiKam (using gphoto as the backend) and iPhoto never had any trouble with it. No idea on the Windows side, though.

    12. Re:Good work by Anonymous Coward · · Score: 0

      You're full of shit. Canon plugs in with any standard USB cable and is immediately recognised as a removable drive. No drivers and no special cable.

      Maybe it's just your piece of shit PC?

    13. Re:Good work by argent · · Score: 1

      Maybe I have more money than you and can look at more cameras?

      Probably. I'm just a code monkey these days.

    14. Re:Good work by argent · · Score: 2, Informative

      "disclaimer: only tested on OS X, not tested on animals, no DLLs were harmed in the making of this message, age 45 and older excluded, milage may vary depending on driving conditions, poster assumes slashdot readers are capable of understanding the concept of 'context', emoticons are optional and may require a surcharge."

    15. Re:Good work by Billhead · · Score: 1

      I have a Canon PowerShot A630 and a S1000(I think, something like that), and I wish that was the case.
      No, I'm stuck with it identifying itself as a camera which won't let me cut & paste.
      HP cameras at least give you the choice between showing as a camera or mass storage.

    16. Re:Good work by 0123456789 · · Score: 2, Informative

      Most (All?) digital cameras allow you to change this setting. On my current one (Panasonic), the setting is called "USB mode" and toggles between PC or PictBridge. I've seen similar settings on Minolta, Nikon, Canon and Olympus cameras; I suggest you try reading the manual or exploring the settings?

    17. Re:Good work by billnapier · · Score: 1

      Actually, it uses either PTP or MTP to talk to you camera over USB. Your USB hard drive is a mass storage device which most likely uses SCSI commands over USB.

      In either case, the OS presents it to you like its an external hard drive.

    18. Re:Good work by Fred_A · · Score: 1

      Maybe one day I'll see a camera with a bog standard USB connector that doesn't need a specific driver just to see the camera's contents as a drive?

      Why would you want to do that anyway when you'll get a much higher transfer rate with a proper card reader than with the crappy USB controller that's on board the camera ?

      --

      May contain traces of nut.
      Made from the freshest electrons.
    19. Re:Good work by ShakaUVM · · Score: 1

      I have an A630 as well, and it fucks up all the time when using the automated XP windows photo downloader thingy. It gets an error while trying to read from the camera, and starts skipping photos. No problems under Vista, though.

      However, nothing stops me from just popping the memory card out and reading the photos off that way, and it goes much faster as well.

    20. Re:Good work by Nimey · · Score: 1

      I had a Sony camera circa 2003 that *required* drivers installed first. Cthulhu help you if you connected the camera w/o installing drivers, because XP couldn't see it and despite my best efforts, it never would after that. Good job we had another computer.

      --
      Hail Eris, full of mischief...

      E pluribus sanguinem
    21. Re:Good work by Anonymous Coward · · Score: 0

      I've meant to post that anonymously!
      Stupid, stupid, stupid!

      Taco is gay!

    22. Re:Good work by tepples · · Score: 1

      I hope you do understand that posts on slashdot can actually be replies to other posts, not just to the article itself.

      Comments below the 50 top rated usually aren't even downloaded. Because of this, it's easier to get comments understood if you Quote Parent.

    23. Re:Good work by dfn_deux · · Score: 1

      Seems a bit presumptuous to say that the parent poster doesn't know how his/her own gear works. I've seen cameras which use PTP/MTP (basically the same protocol, but I've also used plenty that were detected (as indicated by kernel messages in linux) as standard usb storage devices, Actually, more of the digicams *I've* used worked in the later fashion.

      --
      -*The above statement is printed entirely on recycled electrons*-
    24. Re:Good work by Anonymous Coward · · Score: 0

      Maybe one day I'll see a camera with a bog standard USB connector that doesn't need a specific driver

      Try plugging a Canon S3 into a computer that never had any Canon hardware on it. Perhaps your ass is so slack from pulling such stupidities out of it so often.

      Ahh. So you have *ONE* camera that's broken, so therefore *ALL* cameras are broken the same way? All you need to do to "see a camera with a bog standard USB connector that doesn't need a specific driver" is to open your eyes.

      Sounds like you're the one who's "pulling stupidities".

      You need the correct USB cable because the camera tries to act as a host (so it can drive a printer). Thing is, all these cables look exactly the same.

      The cables look exactly the same because they *ARE* exactly the same, shithead. Even cameras that can do PictBridge (ie. ones that "can drive a printer") use the exact same cables as any other.

      You need to install Canon's sheisse to access the camera.

      Sorry, but are you honestly claiming that Canon wrote gphoto? Because I'm pretty sure they didn't have anything to do with it.

      Honestly, does it hurt to be that stupid?

    25. Re:Good work by Anonymous Coward · · Score: 0

      Older or low & mid-range cameras will present themselves as a USB Mass Storage device. My wife has a Kodak EasyShare that does just this. PTP is actually a fairly new protocol.

    26. Re:Good work by RichiH · · Score: 1

      Because every computer out there has an USB port. Even the 10+ year old laptop I use for photo backup & resizing while on the road. And if the thing needs to run the whole night to grab & resize, I don't care. That's when I am sleeping, anyway.

  3. Isn't this a good thing? by Anonymous Coward · · Score: 0, Insightful

    It wasn't that long ago that I read here how the DMA capability of FireWire devices is a gaping security hole. Shouldn't we feel safer that most compact flash devices don't have the same problem?

    1. Re:Isn't this a good thing? by Anonymous Coward · · Score: 0

      It's funny that sarcasm can be conveyed merely be checking the "Post Anonymously" box.

    2. Re:Isn't this a good thing? by Anonymous Coward · · Score: -1, Flamebait

      It's funny that long-winded essays of anal sex and frosty piss can be conveyed merely by checking the "Post Anonymously" box.

  4. Creative by negRo_slim · · Score: 3, Insightful

    Reminds me of the infamous Soundblaster crackle... Which in this thread is being discussed around X-Fi hardware. Even though I can remember the very first Live!'s giving me and my friends the problem years ago. I don't recall the exact details of the situation but I believe it was an improper PCI implementation.

    --
    On the Oregon Cost born and raised, On the beach is where I spent most of my days
    1. Re:Creative by 77Punker · · Score: 3, Informative

      It's pretty fascinating how the company that appears to be the market leader is also the worst in terms of actually delivering a good sound card. Then again, maybe it shouldn't surprise me since they're also the biggest liars. I got bitten twice.

      NEVER AGAIN

    2. Re:Creative by negRo_slim · · Score: 1

      Well like I said we had problems with the cards, but as components changed the problem would fade away. Right now I run an el cheapo Audigy SE and couldn't be happier with it. When it was a problem it was a big problem, but when it's gone... at the end of the day I'm glad to have an SB in my rig.

      --
      On the Oregon Cost born and raised, On the beach is where I spent most of my days
    3. Re:Creative by Anonymous Coward · · Score: 0

      How about every single VIA chipset made with PCI slots? Don't bother trying to use any heavy DMA on a VIA board (like say... a video capture card). See what MythTV's folks have to say about VIA.

    4. Re:Creative by 77Punker · · Score: 1

      You wouldn't have been happy if you bought the Audigy LS when it was new and then Creative didn't make drivers that worked with XP SP2 until Vista was released. Not to mention the fact that after those drivers came out, it wasn't compatible with 2.1 speakers in hardware mode; it would only do surround sound.

      Repeated contact with Creative changed nothing; their only answer was reseat the card, reinstall drivers and so forth. I did all of that many times, and they never cared to do anything about it.

      Now I have an Audigy 2 ZS platinum which is for the most part a decent card, but it does not live up to the features it's supposed to have. One of the things I was looking forward to was the fiber optic input. Turns out NOBODY can get that input to work. Also, it doesn't sample as quickly as it claims, or do 24-bit properly.

    5. Re:Creative by negRo_slim · · Score: 1

      You wouldn't have been happy if you bought the Audigy LS when it was new and then Creative didn't make drivers that worked with XP SP2

      That's why I bought the Audigy SE for $30, I noticed it was more akin to the Live! series then anything else. So I knew what to expect and I really couldn't justify spending any more on features I wouldn't use or a handful of frames per second I won't notice.

      --
      On the Oregon Cost born and raised, On the beach is where I spent most of my days
    6. Re:Creative by makomk · · Score: 2, Informative

      Of course, the only reason Creative are the market leader is because they bought out and killed off anyone who looked like they might actually be a viable competitor...

    7. Re:Creative by Anonymous Coward · · Score: 0

      Me too. I got bitten three times.

      NEVER AGAIN

    8. Re:Creative by zippthorne · · Score: 1

      Why is that surprising? The same is true in printers, and probably a whole slew of other products.

      --
      Can you be Even More Awesome?!
    9. Re:Creative by blahplusplus · · Score: 1

      "Which in this thread [creative.com] is being discussed around X-Fi hardware."

      I have an X-fi (the full version with the faceplate) and I had the 'crackle', but you assume end users know what their 'crackle' causes actually IS, most users I imagine are quite doltish, although some might genuinely have problems but I imagine it's a small group. For me and I found out the crackle was actually because of the soundblaster faceplate 'IDE cable' that connects the card to the faceplate for audio out.

      Once I moved it around a bit away from other devices, the crackle was gone. It was picking up interference from other devices inside the system. I noticed this with (older) video cards a lot. If a video card is really close to a soundcard you'll you'll hear the noise out of your soundcard when your card is being used heavily.

  5. Lexar and Sandisk should be good by AaronW · · Score: 3, Informative

    I have been using a Lexar 300x UDMA CF card for a while in my camera (which supports UDMA) without any problems. I also know many people are using the Sandisk UDMA cards without problems as well. Both were also certified to work with my camera (Nikon D300) by Nikon.

    --
    This post is encrypted twice with ROT-13. Documenting or attempting to crack this encryption is illegal.
    1. Re:Lexar and Sandisk should be good by LanceUppercut · · Score: 5, Interesting

      How do you know that it indeed works in a full-fledged UDMA mode and not in some half-assed workaround mode, used specifically because of the problems in question existing in the cards' controllers. Did you reverse engineer the camera's firmware?

    2. Re:Lexar and Sandisk should be good by AaronW · · Score: 4, Insightful

      It would not be possible to get the performance the camera gets if it did not use DMA mode. It may be that it uses 1K blocks like the article says they used for a workaround. The cards also work fine in UDMA capable external readers, otherwise I would be seeing a ton of messages in the camera forums I frequent. Sandisk and Lexar UDMA CF cards are frequently used with the new cameras that can support it and are widely used by professional photographers.

      Also, the article said that the Sandisk card they tried worked. They did not mention anything about Lexar but did mention problems with Transcend, which is not certified for my camera.

      --
      This post is encrypted twice with ROT-13. Documenting or attempting to crack this encryption is illegal.
    3. Re:Lexar and Sandisk should be good by Anonymous Coward · · Score: 0

      I use a Lexar 300x UDMA card with a IDE-CF adapter under Solaris. It does work as advertised, but doesn't have write cache support like a HDD would (naturally)

    4. Re:Lexar and Sandisk should be good by ArtistFrmrlyKnwnAsAC · · Score: 3, Informative

      I can't vouch for cameras, but I created a CF-based hard drive to boot my Windows XP tablet PC using one of these. It has two CF slots, and my tablet's IDE controller supports UDMA. In Windows, you can check what UDMA/PIO mode your disks are in by clicking the Advanced Settings tab on the IDE adapter's property page in Device Manager.

      The first device I tried was the cheapest UDMA CF card I could get my hands on (233x 16gb Ritek), and after a few disk driver errors, it dropped out of UDMA mode and the laptop went from ~40 seconds to ~4 minutes to boot. When in PIO mode, it would run in fits and starts whenever more than one app was accessing the drive. Now I have two 16gb Transcend 300x UDMA4 cards hooked up to it and it's easily 2-3x faster than my old mechanical disk.

      Something interesting to note is that I can't get anything approaching the speed of the Addonics IDE-CF apapter out of any USB CF adapter I could find. They generally run fast, just not as fast.

    5. Re:Lexar and Sandisk should be good by Dishwasha · · Score: 1

      Many of times the problem is not in the CF card, but instead in the system adapter. I originally tried to use the Lexar 300x using the commonly sold SD-CF-IDE-A and the Linux kernel will hang even when specifying ide=nodma and it spits out some error codes. I then purchased a CF to SATA adapter from Addonics and everything works like a charm.

    6. Re:Lexar and Sandisk should be good by Anonymous Coward · · Score: 1, Interesting

      Something interesting to note is that I can't get anything approaching the speed of the Addonics IDE-CF apapter out of any USB CF adapter I could find. They generally run fast, just not as fast.

      Strangely Hard drives connected through a USB adapter run slower than those connected through the IDE interface. Hmm, this couldn't have anything to do with USB, could it? </sarcasm>

      Basically what I'm saying this isn't really interesting if you know USB is crap for data transfer, which I thought most people here knew. Though if you didn't already know this, I can see why you thought it interesting.

    7. Re:Lexar and Sandisk should be good by Mattsson · · Score: 1

      To see if you get real UDMA, put the card in a ATA->CF adapter and see if you can use UDMA.
      Since you then are using it as a regular IDE-device, you can easily verify it.

      --
      /.Mattsson - My native language is not English, so please don't whine over linguistic errors. (That's lame anyway...)
  6. From the utterly irrelevant department by Gothmolly · · Score: 2, Funny

    What's next, some USB mice fail at implementing the USB 2.0 standard? Or some random printer which claims to support PCL really doesn't?

    Geesh, talk about a slow news day.

    --
    I want to delete my account but Slashdot doesn't allow it.
    1. Re:From the utterly irrelevant department by maxume · · Score: 1

      On a slow news day, the oddest stories get posted and people often get interpreted in an excessively literal fashion.

      --
      Nerd rage is the funniest rage.
    2. Re:From the utterly irrelevant department by karnal · · Score: 1

      This news is actually extremely important to me; I bought a CF to IDE adapter to mess with and am thinking of converting two of my machines to use compactflash cards:

      1. Laptop
      2. PC in garage

      The PC will probably get the first set-up; no need to run the aging 80 gig hard drive into the ground. Especially in the harsh conditions there. The laptop will be a project "if I get around to it" but would be cool to do, what with all of the SSD talk nowadays.

      Anyone have any ideas on Linux on CF (limiting writes etc?)

      --
      Karnal
    3. Re:From the utterly irrelevant department by the+99th+penguin · · Score: 1

      Anyone have any ideas on Linux on CF (limiting writes etc?)

      Here are some links:

      Also most other eee laptop configuration guides you can find.

    4. Re:From the utterly irrelevant department by Anonymous Coward · · Score: 1, Informative

      Try this for tips:
      http://www.cyrius.com/debian/nslu2/linux-on-flash.html

    5. Re:From the utterly irrelevant department by tepples · · Score: 1

      Anyone have any ideas on Linux on CF (limiting writes etc?)

      Look at what Puppy Linux does: Don't use a swap file. Mount your temporary file systems in RAM.

      As for the commonly expressed fear of hitting some claimed limit of 10,000 writes per sector, that fear is overblown. The controller chips in modern CF and SD cards should be able to use the 7.4 percent difference between 2 GB and 2 GiB to spread the writes around the physical sectors. And if you can find SLC (single level cell) flash, its speed and durability might be worth it.

    6. Re:From the utterly irrelevant department by toddestan · · Score: 1

      Well, it is important to point out that there are differences in memory cards people might want to consider. Most people I know consider all memory cards to be functionally equilivent and just buy the cheapest one they can find at the size they want.

    7. Re:From the utterly irrelevant department by DAldredge · · Score: 1

      It's almost like this is a site for nerds or something.

  7. SanDisk cards are usually a safe bet. by kennyj449 · · Score: 3, Interesting

    I can vouch from personal experience with their engineers that their cards rated for 30MB/s or higher all support UDMA 4 or higher, and I've done tests of my own to verify this. Not all ExtremeIII cards support UDMA though; the ones that don't specify a speed of 30MB/s are instead rated for 20MB/s, which can be quite easily achieved using PIO6 (although less efficiently.) These cards might support UDMA, but since there's no *need* for it, there are no guarantees.

    Also, I'm pretty sure Lexar cards rated for UDMA do perform as advertised. I can't vouch for other manufacturers. Additionally, be wary of fake cards (ebay is especially prone to fake card sales) as they're never going to perform to your expectations.

    1. Re:SanDisk cards are usually a safe bet. by AaronW · · Score: 2, Informative

      I can at least vouch that the Lexar UDMA card works as advertised in my UDMA capable camera. Fake CF cards are a big problem. Avoid buying CF cards on Ebay and only buy from reputable dealers or you might get a fake Chinese card and have nothing but trouble.

      --
      This post is encrypted twice with ROT-13. Documenting or attempting to crack this encryption is illegal.
    2. Re:SanDisk cards are usually a safe bet. by code4fun · · Score: 1
      The problem with 3rd party vendors like Lexar and Kingston is that they get ATA controllers and NAND chips from vendors that are willing to sell them at the lowest cost. They slap together whatever they have in order to provide the consumers the low cost CF. Having said that, the CF cards should follow the ATA specifications. In this case, you should be able to send it the identify command (0xEC) to read the drives hardware capabilities (512 bytes of info). Under Linux, you should be able to use hdparm to dump out the info. I would trust the bits stored in the parameter area over any vendor advertised brochure unless they are technical specs that came from the chip controller manufacturer.

      So, for a given label CF, the controller underneath may be different. In some case, UDMA may work and it doesn't work in others. Even though they have similar labels, the manufacturers have some markings that differentiate the CF parts. The industrial and military grade parts have tighter control over the parts and they usually charge significantly more since they are qualified to operate in extreme temps and harsh conditions.

  8. Open source?? by BhaKi · · Score: 1

    In his quest to create an open source video camera...

    What the hell is an open source video camera? I've heard of open source software, but what the hell is open source hardware??

    --
    The largest prime factor of my UID is 263267.
    1. Re:Open source?? by edlinfan · · Score: 2, Informative

      Perhaps hardware which is extensively documented, with all documentations/plans/schematics licensed under the GFDL or similar?

      Just my $0.02

    2. Re:Open source?? by BhaKi · · Score: 1

      You could just call it "Programmable Hardware" or "Documented Hardware".

      IMHO, "Open Source Hardware" is just a clever phrase used by many hardware people to leverage advantage of the well-marketed "Open Source" phrase.

      --
      The largest prime factor of my UID is 263267.
    3. Re:Open source?? by russellh · · Score: 1

      What the hell is an open source video camera? I've heard of open source software, but what the hell is open source hardware??

      Um, if I were to guess, this would be a hardware video camera with open source firmware, or a reference platform for building a functional video camera like a PC, where you'd plug together lenses, buttons and sensors in a case. It probably would look like RED.

      --
      must... stay... awake...
    4. Re:Open source?? by Anonymous Coward · · Score: 1, Funny

      I asked the same question, and was able to educate myself in about 30 seconds with Google. Try that next time...

    5. Re:Open source?? by Anonymous Coward · · Score: 0

      Uhhh...one that you can take apart and add some capacitors.

    6. Re:Open source?? by Mr+Z · · Score: 1

      If the schematic files are available in source format, and possibly the CAM information (Gerber files, drill files, etc), I'd call that open source, since that's the material used to generate the boards. It's one thing to print a schematic. It's quite another to publish the board layout in an editable form.

      I haven't looked at what this project is doing, but it sounds like the latter.

      --Joe

      --
      Program Intellivision!
    7. Re:Open source?? by AndreyFilippov · · Score: 2, Informative

      http://www.fsf.org/resources/hw/cameras

    8. Re:Open source?? by AndreyFilippov · · Score: 2, Informative

      Yes, we do have it all posted, but unfortunately we can not post the PCB layout "source" - this is the last part of the camera design were I use some proprietary software running on top of the proprietary OS and saving data in proprietary format. It is a shame, I agree - but I could not find a good FOSS substitute. I would definitely pay twice (or more) for the same functionality GPL-ed software, maybe it is possible to to make a pool to buy some software to be free?

    9. Re:Open source?? by Ig0r · · Score: 1

      FWIW, Cadsoft Eagle is a proprietary schematic capture/layout program that has a free version that anybody can use to view or print (but not edit) design files written by the full versions.
      Also, Cadsoft has a much lower price (around $150) if you're using the full version for non-commercial activites. Eagle seems to be quite popular for the hobbiest market because of this.

      --
      Soma: because a gramme is better than a damn.
    10. Re:Open source?? by AndreyFilippov · · Score: 3, Interesting

      Yes, I know Eagle. But it can not handle the the designs we have, and it is still not a free software. So - we'll have to wait.
      Elphel would put some $50K in the pool (if there was one) to buy a serious PCB CAD software no make it GPL-ed.

    11. Re:Open source?? by Anonymous Coward · · Score: 0

      Dictionaries are quite popular among the people who know how to spell "hobbyist".

    12. Re:Open source?? by thexile · · Score: 1

      So that it runs Linux.

    13. Re:Open source?? by Anonymous Coward · · Score: 0

      Hey Andrey,

      I just did a PCB layout using Kicad. It seems to now have enough basic functionality to do real PCB designs. There are still some limitations though. I will be glad to answer any questions about Kicad if you are interested in looking at it again.

      -Gary Embler

  9. Slower with DMA disabled? by foobrain · · Score: 0, Troll

    "This means successful movement of data to and from the device takes much more time with DMA disabled."

    Oh, really? If so, the devices works as they should.

    1. Re:Slower with DMA disabled? by IllForgetMyNickSoonA · · Score: 1

      The parent is most obviously pointing out a mistake in the summary, and NOT trolling!

  10. Compact Flash by Lord+Lode · · Score: 1

    Why do they want to use Compact Flash cards? I think SD cards are more common, at least in the cameras I had so far, correct me if I'm wrong. And maybe SD and SDHC cards don't have those problems?

    1. Re:Compact Flash by stevo3232 · · Score: 2, Informative

      Compactflash cards are available in larger sizes, work as IDE devices (which SD cards do not afaik) and are faster.

      --
      s.clementmonkey@sympatico.ca, remove the 'monkey'.
    2. Re:Compact Flash by maxume · · Score: 3, Informative

      Compact flash is/was the standard on the high end. SD is making some inroads, but for a long time, fancy cameras had CF slots and that was your choice.

      --
      Nerd rage is the funniest rage.
    3. Re:Compact Flash by Sen.NullProcPntr · · Score: 4, Informative

      I'm guessing size is the main factor, according to Wiki SD has already maxed out at 32GB while CF has a theoretical max of 137GB. You need a lot of storage space for video.

    4. Re:Compact Flash by AndreyFilippov · · Score: 5, Informative

      Two of the reasons wewrw already mentioned: 1 - I've got IDE interface "for free" in from the processor chip, just needed connector. 2 - CF cards are higher capacity. 3 - I can download CF and ATA specs from the Internet, while SD (when I checked it) was much more difficult to get.

    5. Re:Compact Flash by minhmeoke · · Score: 2, Informative
      What about MMC? According to Wikipedia, they have a theoretical maximum capacity of 128 GB, and MMCs can be used in most devices which support SD cards. Also note that

      As of February 2008, the specifications version 4.3 (dated nov 2007) can be requested from the MMCA, and after registering downloaded free-of-charge.

    6. Re:Compact Flash by tepples · · Score: 1

      according to Wiki [wikipedia.org] SD has already maxed out at 32GB while CF has a theoretical max of 137GB

      SD maxed out at 2 GiB, then it had an update to SDHC (secure digital high capacity) that maxed it at 32 GiB. Yes, that was a pitiful upgrade, buying only six Moore years of relevance. CF is based on parallel ATA, which too used to max out at 137 GB before the move from 28-bit to 48-bit sector addressing. So couldn't the CF Association make a new "CFHC" spec for CF cards big enough to need 48-bit addressing?

      You need a lot of storage space for video.

      At 1080p, or higher? Wouldn't a high-end HDTV camera need to stripe data across the cards anyway?

    7. Re:Compact Flash by toddestan · · Score: 1

      Physical size might be another reason why CF is seen on higher end cameras. Microdrives used to be a lot more popular back before flash became so cheap, and for Microdrives you need a CF slot as the SD form factor is way too small.

    8. Re:Compact Flash by marcansoft · · Score: 1

      You can get the Simplified SD spec, which is basically the normal spec minus the DRM and some other unimportant details.

    9. Re:Compact Flash by Anonymous Coward · · Score: 0

      Not quite true. The SD Association limited SD cards to 32GB, but SDHC's specification allows for 2048GB (or 2TB) cards (thanks to sector addressing vs the block addressing of normal SD cards. This is why SDHC cards are not compatible with SD readers/writers). I'd wager that version 3 of the SD spec will allow larger SDHC cards to be made, so in this regard SD could be better than CF if it wasn't restricted by the SD Association

    10. Re:Compact Flash by Anonymous Coward · · Score: 0

      We evaluate lots of CF cards for embedded systems we develop. We do not see quite the same behavior that you do. A couple of months ago, we bought a variety pack from newegg and best buy. All of the cards that advertised MDMA did MDMA fine, and those that supported UDMA did UDMA fine. Did you try these cards in normal linux systems?

    11. Re:Compact Flash by lostchicken · · Score: 1

      While the primary SD interface is kinda complex, SD cards are required to support an SPI interface, which is pretty much the most brain-dead simple interface imaginable.

      Most microcontrollers will support it natively, and it's incredibly simple to implement in hardware and software. It's what I usually use when I need to back a PIC with lots of storage.

      --
      -twb
  11. Snort. by porkchop_d_clown · · Score: 1

    Maybe you need to look at more cameras, then. The last couple I've owned have done that.

    --
    Clear, Dark Skies
  12. Transcend 133x works well with UDMA for embedded by bconway · · Score: 1

    I run an 8 GB Transcend 133x in my Alix board as a router/firewall on FreeBSD, and the BIOS and OS pick it up as UDMA33 without a problem. I get sustained reads of 33 MB/s and writes of about 9.5 MB/s.

    --
    Interested in open source engine management for your Subaru?
  13. Andrey Filippov by pushing-robot · · Score: 1, Funny

    God damn it, why can't I have that last name?

    --
    How can I believe you when you tell me what I don't want to hear?
    1. Re:Andrey Filippov by maxume · · Score: 2, Funny

      I imagine you could, if you really wanted to.

      --
      Nerd rage is the funniest rage.
  14. IDE Compatibility Issues by Migraineman · · Score: 4, Informative

    I've been struggling with CF cards in embedded applications, and I can verify that they don't always comply with the interface specs. I've gone through at least a half-dozen different CF card brands, and all display some form of misbehavior if they're put on an IDE chain with another device. By themselves they work fine, but add a CD-ROM or a hard drive, and the system will fail with either bus timeouts or stalled transfers. My suspicion is that the CF card vendors are playing games with performance metrics in photography apps, and in those environments they can bend the spec because there's exactly zero chance of another device being installed on the interface.

    As far as I can tell (without a bus analyzer,) there's something hinky happening during device auto-detection and initialization. Many times, the CF card will be detected as the Master device, but no Slave device will be detected. Swap to a different brand CF card, and the symptom will change - both devices will auto-detect, but the IDE bus will throw timeout errors during boot. Swapping in just about any not-a-CF-card device, and everything is fine.

    1. Re:IDE Compatibility Issues by Jeff+DeMaagd · · Score: 1

      I agree, they probably assume that it's going to be used in a single drive bus. I think I have IDE to CF adapters that allow the user to set which is master and which is slave. I haven't tried to use a non-CF device with a CF device on the same bus.

      I doubt they consider embedded use at all. Digital cameras are probably still the leading use of CF cards by far, but that's being pushed out a bit as no point and shoot seems to use it, and even low end dSLRs are switching over to SD.

    2. Re:IDE Compatibility Issues by riflemann · · Score: 3, Insightful

      A while ago I built my mythtv frontend, (based off a T-Online vision s100 box) and elected to use a CF card for storage within the unit - the box is entirely free of moving parts, so CF made sense.

      I bought one of those IDE to CF adapters off ebay, and found that when I turned on DMA, the IDE bus would basically lock up, and pretty much end up useless.

      After a lot of fiddling and digging around, I discovered that the adapter did not connect the required pins for DMA transfers to work. Old-skool CF never had DMA, so this extra pin is only a recent addition to the standard.
      Anyway, I soldered in a short wire to hook up this pin, and now I get respectable dma transfers.

      The moral of the story - it might not be the CF card that is causing DMA failure, but the adapter it's hooked into.

      --
      Sparks:Gadget:Beer Maker
    3. Re:IDE Compatibility Issues by Migraineman · · Score: 1

      I've gone through the gamut of permutations - the task is one for work. Our CF-to-IDE adapters have been buzzed-out to make sure the DMA lines weren't pegged. There are several on the market that have the DMA signals tied high or low, though I can't comprehend why. We've also made sure the DASP and PDIAG signals are connected (those are necessary during the auto-detect phase.) We have fielded products that have a custom PCB connected to a Cirrus EP9312 Arm9 CPU. The CF adapter in that app works fine, including DMA transfers.

      I'm convinced that the CF card vendors are pandering to their primary market, which I believe is the digital camera folks. There's strong demand for high performance, and IDE isn't known for that. I can easily see Big Camera Company handing a briefcase of cash to CF Card Vendor to improve performance by altering the bus interface. The factory-specified card works great, but aftermarket cards don't. Funny that.

      Given the variance between manufacturers of CF cards, we've been unable to find a solution that we have any confidence in. We require products with CF cards to be designed such that the CF card is alone on the IDE bus. Other IDE peripherals go on a separate connection. That's annoying in some situations where we're pressed for space, but is seems to be necessary.

    4. Re:IDE Compatibility Issues by adolf · · Score: 1

      I also have a few no-moving-parts machines running with various cheap Chinese CF-to-IDE adapters, some of which are a few years old. They are all, unilaterally, quite slow. For what they're doing (a web browser for Thottbot, a processor for audio, and an antique 386 laptop running antique Slackware), speed isn't important -- and the 386 will obviously not work with DMA anyway -- but it'd be nice if they booted faster.

      Which pin should I be investigating at to see if this might be part of the problem? Looking at a CF pinout doesn't show me anything obvious.

      --
      Kid-proof tablet..
    5. Re:IDE Compatibility Issues by Mattsson · · Score: 1

      I've also seen this behaviour.
      One or two CF-cards on one IDE-bus: No problems
      One CF-card and anything else on the same bus: The CF-card fails to enter ATA-mode, which means that it tries to talk to the IDE-bus as if it's a CF or PCMCIA-port.

      Haven't seen any card that doesn't show this problem, but I've only tried about 8 - 10 different cards.

      --
      /.Mattsson - My native language is not English, so please don't whine over linguistic errors. (That's lame anyway...)
  15. CF inside the cameras do not use "True IDE" mode by AndreyFilippov · · Score: 5, Informative

    In the article I was only describing CF working in "true IDE" mode, inside the cameras thy usually do not use it, so do not care much about the problem I've got. But it is important if you try to connect the camera with a simple adapter instead of the HDD

  16. I think I hear Violins by billcopc · · Score: -1, Troll

    Cheap Chinese mass-produced gadgets fail to perform as advertised, C-list Slashdot editor posts trollish story, film at 11!

    --
    -Billco, Fnarg.com
  17. What about these, CF to IDE adapters? by Anonymous Coward · · Score: 0

    I have used adapters similar to these:
    http://www.alfa888.net/ebay/conline/c4photo/ce0251one.jpg

    What's wrong with them? I haven't had any trouble with them.

    1. Re:What about these, CF to IDE adapters? by MoFoQ · · Score: 1

      it's not just about the CF to IDE (or CF to SATA) adapters but also the controller chip within the CF card as stated in the article.

  18. Pffft. You need to be careful. by Anonymous Coward · · Score: 0

    There's more to things than just that. I tried one of Sandisks' latest high-speed offerings last November, and the thing wouldn't even boot!!

    I have no doubt that it's capable of running at the speeds they claim. But if they can't even get the very basics right, their interface is broken. Pure and simple.

    Oh, and this was with RedHat EL 5 at the time, and with Fedora.

    So be careful out there. Brand name is not everything. This is still immature technology.

    1. Re:Pffft. You need to be careful. by kennyj449 · · Score: 1

      Are you sure you had it in Fixed Disk mode? Most OSs will fail to boot if the card is in Removable mode. All CF cards share this characteristic, and most are in Removable mode by default. A good CF-IDE adapter can (and should) put the card in fixed disk mode, but not all will do so.

  19. Fixed that for you by hostyle · · Score: 1

    I, the orginal and only Anonymous Coward, have a 2 inch junk!

    This reply is GPLv3 licensed.

    Original comment available on request.

    --
    Caesar si viveret, ad remum dareris.
  20. Market leader? by PCM2 · · Score: 1

    Wait a minute ... there's still a market for sound cards? I am perplexed. Last I checked, there wasn't a motherboard made that didn't have onboard SPDIF, not to mention plugs for 5.1 speakers. Who are these people who buy sound cards?

    --
    Breakfast served all day!
    1. Re:Market leader? by 77Punker · · Score: 2, Interesting

      It's like the difference between an onboard video setup and a "real" one. People who need more features always have to pay a little more for them.

    2. Re:Market leader? by nfgaida · · Score: 1

      No.. there is a difference. Onboard video isn't powerful enough to play most new games at any decent frame rate. My onboard sound doesn't prevent me from playing any games.

      I think it is more for audiophiles now.

      --
      *elevator music plays*
    3. Re:Market leader? by springbox · · Score: 1

      The same people who also buy 1kW power supplies

    4. Re:Market leader? by ShakaUVM · · Score: 1

      >>Who are these people who buy sound cards?

      Offloading the sound processing to the SB X-Fi bought me about 10-20 fps in games when I benchmarked it immediately before and after installation. On-board sound requires your CPU to do math, and if you have a lot of stuff going on, with various filters being applied to them, it makes a noticeable difference. More importantly, it stopped the occasional hitches and slowdowns I'd get, especially with winamp running in the background.

      Plus, the sound that comes out of it sounds a lot better (or more precisely, can sound a lot better, depending on your settings).

      I'm not someone that likes to buy toys or waste money on random crap for my computer, but I do think it's worth the hundred bucks, especially because my system stopped hesitating, which was bothering the hell out of me.

    5. Re:Market leader? by 0xygen · · Score: 1

      For gamers, there is a massive difference.

      DICE's Battlefield 2 uses EAX to provide detailed positional audio on X-Fi cards.

      I have played a fair amount of Battlefield 2, around 400 hours. About half way through this, I upgraded from onboard audio to an X-Fi Fatal1ty. My Kill to Death ratio went up by about 25% within a few days.

      For me, the stats speak for themselves. Same applies to Race Driver GRID currently... there is no need to use the mirrors if you have reasonable hearing.

      I understand this can be done in software - the point is, it is not at the same point currently.

    6. Re:Market leader? by djdavetrouble · · Score: 4, Funny

      I upgraded from onboard audio to an X-Fi Fatal1ty. My Kill to Death ratio went up by about 25% within a few days.

      NEVER underestimate the power of.... Celebrity Endorsement !

      Get the Fatal1ty mousepad to go up another percent.

      --
      music lover since 1969
    7. Re:Market leader? by Anonymous Coward · · Score: 0

      That isn't true. Using onboard sound I experienced lots of sound stuttering, dropouts and half-assed EAX support in most games. Getting a discrete sound card fixed those problems.

    8. Re:Market leader? by CastrTroy · · Score: 1

      Personally, I find my hearing gets a lot better just putting on a good set of headphones. It really helps to pin down exactly where the sound is coming from. It's a lot easier than trying to get perfect placement on your 5.1 setup.

      --

      Anthropic principle: We see the universe the way it is because if it were different we would not be here to see it.
    9. Re:Market leader? by CastrTroy · · Score: 1

      So if you offload the sound processing to the sound card, and the graphics processing to the graphics card, what exactly is left for your CPU to do?

      --

      Anthropic principle: We see the universe the way it is because if it were different we would not be here to see it.
    10. Re:Market leader? by toddestan · · Score: 1

      Well, some people like myself have a speaker set up that doesn't have digital inputs, and the analog outputs on the motherboard are noticably noiser. And besides, few onboard sound cards have powerful enough amps to drive a good set of headphones at a decent volume.

      Of course, you are probably right about the market. My sound card is an Aureal Vortex that I bought for my K6 system back in the days before onboard sound became ubiquitous. Quite possibly the oldest component in my computer, and I don't remember it costing very much either back in 1998.

    11. Re:Market leader? by nfgaida · · Score: 1

      Positional audio would be a benefit, assuming that can't be done in software/or by onboard sound.

      While I play games, I fear my days of solid game playing are past. Kids and work take up too much of my time (read that as: my reaction times have slowed so that I can not compete with twitch gamers in their teens who have hours to burn practicing), so my game playing is usually done with my 360, Wii or an RTS type game on my PC.

      In conclusion, get off my lawn you damn kids.

      --
      *elevator music plays*
    12. Re:Market leader? by FateStayNight · · Score: 1

      AI

    13. Re:Market leader? by andy_t_roo · · Score: 1

      run physics sims?
      continually re-ballence visual object higherachy for optimal frame rate?
      run windows?

    14. Re:Market leader? by ShakaUVM · · Score: 1

      >>So if you offload the sound processing to the sound card, and the graphics processing to the graphics card, what exactly is left for your CPU to do?

      Stuff.

      But no, seriously, whatever it is that pegs my CPU when running Crysis or Age of Conan.

      Offloading the sound processing to the card makes a very noticeable difference.

    15. Re:Market leader? by 0xygen · · Score: 1

      Yep, I agree - I use the cheaper stereo version of the Medusa headset with the X-Fi card set to headphone mode. I have tried the 5.1 version of the Medusa headset, and do not find it that much better for the money.

      This does actually provide excellent virtual surround, which is why I think I need the X-Fi.

      I had to go back to my onboard Realtek HD-Audio, and tried it in AC97 mode too a few weeks ago. It was not a nice experience.

    16. Re:Market leader? by 0xygen · · Score: 1

      Yeah, the celebrity endorsement nearly put me off.
      I was looking at the lower end cards, but discovered the lowest two X-Fi card do NOT have the real X-Fi chipset, so do not support the hardware acceleration for gaming!

      Personally I do not like glass-style mousemats, I prefer the old fabric ones, so use an Everglide Titan with a Logitech G5 mouse set to a LOWER DPI. I find this is actually more accurate than a smaller surface with high DPI.

      Funnily enough, in actual gaming, I seem to recall Fatal1ty actually plays this way too, but so do a lot of the older serious players. Guess their hands are as damaged as mine too by that age!

    17. Re:Market leader? by 0xygen · · Score: 1

      Yes, I thought this for a few years until discovering Battlefield 2. It took about 3 months for me to get quick enough to be competitive again, so I think you can actually regain these skills.
      Admittedly, BF2 is strategy heavy too though, so it is possible to compensate to for slow reactions to some extent.

      Real twitch games like Unreal Tournament 3 and Quake 3 are still a little beyond my reactions.

      I have found recent racing games are excellent for older gaming - my clan has gamers up to 60 years old. We have all enjoyed a good blast on Race Driver GRID lately, it's pretty accessible to everyone and achieves a great balance of realism and arcade play.

    18. Re:Market leader? by Kattspya · · Score: 1

      The only difference I've noticed on BF2 with extreme sound quality (or whatever it's called) is that you get more channels. I don't hear much or any difference in positional and ambient audio. That audio could even cause a 25% upshot in KDR is so unlikely I don't buy it. It means that 25% of your deaths was from an enemy not in front of you and in audible range. I don't buy it.

    19. Re:Market leader? by 0xygen · · Score: 1

      Part of the serious difference is related to the fact I mainly play Infantry Only these days.

      The downside to IO is that often you are getting sniped without being able to see where from. In this situation, being able to hear whether the sniper is above you and often exactly where they are is a massive advantage. It's enough that I have been accused of cheating a lot more since getting X-Fi.

      The other main situation where it helps which I can tell the difference between software and EAX is you hear boats and helicopters MUCH earlier, and can hear where they are coming from, and often going to.

      You also hear footsteps near you when you enemies are about to run around the corner in front of you whilst capturing flags.

      As you rightly say though, you do have the added bonus of a lot more channels, which definitely is part of why you hear vehicles and players coming from much further away, especially the snipers and support guns which are so lethal in IO.

      It's not the low / high / extreme sound quality setting which makes the difference, it is the Hardware Sound / EAX checkbox.

    20. Re:Market leader? by David+Gerard · · Score: 1

      Or if you want to do any recording. Try playing with Audacity - motherboard sound frequently isn't up to letting you record a track while playing back another.

      It's more than a little annoying that a 1998 PCI sound card beats 2008 motherboard sound hardware.

      --
      http://rocknerd.co.uk
    21. Re:Market leader? by David+Gerard · · Score: 1

      DRM!

      --
      http://rocknerd.co.uk
  21. Try Transcend, but watch for voltage by steve-san · · Score: 3, Informative

    I wonder how often voltage (5V vs. 3.3V) is a factor in UDMA problems...
    Like the previous poster, I use a Transcend CF card to run XP and Ubuntu on a laptop. I recently "upgraded" to the 16GB 300x version, since it was supposed to run at UDMA5. I wrote the review here.

    Short story: According to Transcend, the card has to run at 3.3V in order to run in UDMA5 mode. I'm also using that Addonics 2-card CF-to-IDE adapter, and it doesn't offer voltage choices, so I'm stuck at 5V and the slower speeds -- auto-detected at UDMA4 in XP and UDMA2 in Ubuntu.
    Next up, I'm gonna try this single-card solution, since it has a hardware voltage switch (jumper).

    Oh, yeah -- and for the purposes of mounting these CF-IDE adapters in notebooks, the Addonics is a real pain (super glue was involved), since it doesn't have the same dimensions & threaded holes as a standard 2.5" HD. According to another reviewer, the Syba addresses that.

    --
    What you want is irrelevant; what you've chosen is at hand! - Spock, ST VI
    1. Re:Try Transcend, but watch for voltage by ArtistFrmrlyKnwnAsAC · · Score: 1

      I wonder how often voltage (5V vs. 3.3V) is a factor in UDMA problems...

      A lot less often than you think, probably ;) TFA is about UDMA failing altogether, not a failure in differentiating between 4 and 5. My tablet only supports UDMA4 to begin with, so I didn't experience the issue you described with the Transcend card. I'd be extremely interested to know if you see any speed difference whatsoever between 4 and 5 though, as the physical specs of the card seem to max out at the speeds allowed by UMDA4.

      Also, I found the connector of the Addonics card to be so extremely tight-fitting that I don't need secure it except for plugging it in, so people's mileage is likely to vary on this. Addonics has instructions on their site for snuggly fitting the adapter into your IDE bay, should the connector prove too loose. No super glue required, but it involves cutting a 2" x 3" chunk of foam and placing it into the space that is ordinarily filled by a traditional 2.5" mechanical drive.

      Good luck with that other adapter though.

    2. Re:Try Transcend, but watch for voltage by steve-san · · Score: 1

      Regarding the Addonics AD44MIDE2CF fit, it would be nice if all laptop HD bays were so easily accessible as the one pictured on the Addonics site, but sadly, that's not the case for my machine (IBM T42) and many other laptops.
      My system uses a little caddy & external cover that you must fasten to the HD, then the whole assembly slides into the side of the system. I know many Dells are like this, too (usually w/just the cover, not the caddy).
      Since the AD44MIDE2CF does not have the same dimensions and screw holes as a normal HD, it will not attach to the caddy, and therefore cannot be easily slid into place. That's why I glued the adapter to the caddy, lining up the pins so they'd sit exactly where they would on a normal HD. Now, the whole thing can still be easily swapped out. Come to think of it, without the caddy (like on those Dells), I'd be completely hosed.

      The Addonics CF-IDE adapter seems like a good idea (and it is for many, I'm sure), but I hope this serves as a warning for any other Googlers who are interested in the same solution I've got. It's not exactly plug & play.

      And you're probably right about the voltage not being a deciding factor in TFA, but (at least in the case of the Transcend cards) it has some bearing on the DMA mode, so it may be worth the author's time to investigate it.
      I know I've been absolutely certain in years past that technical issue a,b,c couldn't possibly have been caused by factors x,y,z... only to have to eat crow later.

      --
      What you want is irrelevant; what you've chosen is at hand! - Spock, ST VI
  22. We last visited Elphel and their work... by AndreyFilippov · · Score: 1

    > We last visited Elphel and their work on open source digital cameras in 2002...
    Are you sure? Wasn't it just a week ago?
    http://mobile.slashdot.org/article.pl?sid=08/07/05/1711221

    1. Re:We last visited Elphel and their work... by ColdWetDog · · Score: 1

      > We last visited Elphel and their work on open source digital cameras in 2002...

      Are you sure? Wasn't it just a week ago?a

      Give the editors a break, will you? They don't remember what stories they posted yesterday. They can't spell, they have no grammar skills and now you want them to understand time?

      This is sure a tough place...

      --
      Faster! Faster! Faster would be better!
    2. Re:We last visited Elphel and their work... by waldo2020 · · Score: 1

      It's called Payola

  23. SMI controllers by Anonymous Coward · · Score: 0

    SMI controllers do have a lot of weird little problems here and there, and the firmware updates are numerous. however firmware updates can't be done by the customer, need to be done at the card manufacture's site. There are just too many different controller/flash combos for a given CF card, even from the same manufacture. As far as I know, the fastest CF cards can top out 50MB/s transfer using UDMA mode.. but very few company is making those due to high cost associate with SLC flash.

  24. Is it possible...? by flattop100 · · Score: 1

    It is possible to label the *newspost* as flamebait?

  25. Ooops.. by flattop100 · · Score: 1

    posted in wrong thread.

    1. Re:Ooops.. by Anomalyst · · Score: 1

      whew, you had me worried for a moment.

      --
      There is no right to feel safe thru security vaudeville at the expense of everyone's freedom, privacy and tax money.
  26. Minimig by Belial6 · · Score: 1

    http://en.wikipedia.org/wiki/Minimig

  27. Get off my lawn! by Detritus · · Score: 1

    What happened to the good old days when chip vendors would fall over themselves to give you data sheets, application notes, and anything else you might need to use their products in your design? NDAs were for things like information on unannounced products.

    --
    Mea navis aericumbens anguillis abundat
  28. CF ~= IDE by DrYak · · Score: 1

    Easy !

    Compact Flash form factor is really a down-sized PC-Card 16bits / PCMCIA form factor.
    And PC-Card 16bits is nothing more than cousin of ATAPI which is external and supports hot swapping.
    (Just as PC-Card 32bits is a PCI cousin with hotswapping, and Card-Express has both PCIe and USB2.0 pins).

    There are CF IDE adapters which are mostly passive pin-adapter without any logic, that let you access a CF card using an IDE bus (minus the hot plugging).

    So just plug your compact flash into one of such card adapter.
    If your computer recognize the card in UDMA and can access it without DMA errors, it means it's a true UDMA mode. If you have to switch back to a PIO mode to get it working, it means that some workaround is needed.

    There are a lot of SanDisk cars which *do not* feature UDMA in their retail form, but only in *industry* equivalent models which are more expensive (can confirm it in my own experience).

    I've read on the net that Lexar card better support UDMA (can't confirm, haven't got one yet).

    --
    "Sufficiently advanced satire is indistinguishable from reality." - [Tips: 1DrYakQDKCQ6y52z6QbnkxHXAocMZJE61o ]