Compact Flash and Data

[johnnymk]

Can CompactFlash cards and a USB reader be used as a data storage and transfer device, instead of just for pictures? Would you need any special programs so that each computer would recognize the reader as a piece of hardware, much like a "pen" device?

[johnnymk]

Thanks. With the cost of CompactFlash media coming down, it may be the end of Zip Discs.
Yesterday, I saw a deal on 64 MB Compactflash cards for $19.99 and it made me think about using them for data.

[OC]

It's actually part of the CompactFlash specification that they emulate IDE hard drives. I'm using a 4mb CF card with an IDE adapter as a "hard drive" in my FreeSCO (linux) router. Works great, and the boot times are amazing.

-OC

[hapoo]

where did you get your compactflash-2-ide adaptor OC?

[OC]

hapoo - I got the adapter from Australia: http://www.flashmemory.com.au/shop/shopdisplayproducts.asp?id=3&cat=FlashMemory+Disk+Drives I got the CF-IDE2 model, and it was about $32 delivered. It only took five days to arrive, which was nice. I'm looking to get a second one soon for another project.

chosen - Yes, it can be used as a boot device. Using the adapter, hook it up and detect it in the BIOS just like a normal hard drive. But you MUST do FDISK /MBR in order to make the thing bootable. There is no master boot record on a CF card, so you need to do this to create one. After that, it's bootable.

-OC

[johnnymk]

Why do you only have a 4MB card? Do you have some kind of Operating System on it, too? I am trying to figure what you gain from this setup. Pleez explain...

[OC]

Originally posted by johnnymk
Why do you only have a 4MB card? Do you have some kind of Operating System on it, too? I am trying to figure what you gain from this setup. Pleez explain... Why only 4mb? Simple - I had it lying around and it fits the bill perfectly. I'm running a small distro of Linux (FreeSCO) on an old P100 box. It has 2 NICs and serves as my router/firewall. FreeSCO can be run from a floppy, or optionally from a hard drive.

Now that CF card prices are dropping, I want to go to a more "full" version of Linux. For example, FreeSCO has no CDROM support in the kernel. I want to get a 256mb CF card and do a non-gui install using the latest kernel, which I'll compile to suit my needs.

Once my Linux knowledge is up to the task, I'll revamp my PPro180 box, which right now has an 80Gb drive running Rad Hat 7.1. It's my file server. My end goal for this box is 2 80Gb drives, a CF card as the boot device, the firewall/router capabilites that I currently have with FreeSCO, as well as ftp & web servers. Right now I have a single page hosted on my FreeSCO box, courtesy of Dyndns.org, but transferring files to/from the CF card is a pain cuz I have to remove it from the box and plug it into my USB reader. That means taking the box down, and where's the fun in that?

-OC

[hapoo]

actually i was asking for the same reason OC, My linux firewall/router/web/ftp/file server is running off a normal hard drive 24/7, this way i can give it a break and also increase boot times.

[Ladogaboy]

Wow. I didn't know that there were this many possibilities for CF. Now I'm getting ideas!!! :idea:

[OC]

I had an idea for 4 512MB cf cards in a RAID controller. Can you imagine the speed? Then I realized what the capacity would be, and the experiment wouldn't be worth the cost. :|

-OC

[johnnymk]

oc... assuming you built this 2 GB system, what would be the limiting factor in the transfer of information: The controller card, the speed of the CF card, the amount of memory, or even the CPU speed?
I have seen CF cards that advertise faster transfer speeds. Do you think that the card itself could possiblty be the slowest link in the system or would it be something else?
Also, with USB 2.0 becoming more popular, I wonder if CF cards will take advantage of that new port?

[OC]

I'll have to dig further to know for sure, but I believe the speed of the CF cards would be the limiting factor. Faster CF cards would lead to better performance, just like with hard drives.

To take the experiment further, it'd be interesting to compare ATA33, 66, 100, and 133 controllers with the same mobo/cpu and CF/IDE adapter setup to see if the system can go faster than the CF memory can. But still, setting up a RAID array using CF cards would be prohibitivly expensive. So for me it'll just remain a fun idea.

-OC

[johnnymk]

As I was touring another deals site, I noticed they were advertising a 4X Compact flash card. The rating for the card is only 600 KB per second. That's less than a Meg per second! So I guess that USB 2.0 has no adavantage for theses cards yet.