[Coco] 2gig CF card killed

[Joel Ewy]

Roger Taylor wrote:
> Well, I think I've successfully killed a nice Lexar 2gig CF card after
> many attempts of installing Windows 98SE on it to run on my Compaq
> IA-1 internet appliance.
> ...
>
> I did so many installs and formats, that I think I reached the
> ~300,000 erase/write limit of the card.
>
My understanding was that the write limitation is per-memory location,
or per-cell, not for the entire card.  I also have this vague
recollection that at least some kinds of modern flash memory module (CF?
some USB memory sticks?) try to spread writes out across the memory
locations to reduce that effect.  Maybe I'm wrong about that though.

I find it a little hard to believe that what you report doing could have
reached that limit, unless Linux and Windows were creating and making
much use of swap files on th CF.  I could see that wearing it out. 
Maybe the Windows installation routine uses an exorbitant number of
individual writes?  Maybe you should try installing Windows on an
ordinary hard drive, then cloning the drive onto the CF after the
installation is complete.  That would reduce writes to a bare minimum. 
> My question is, with the IDE interfaces in use and people using CF
> cards as their main CoCo HD, how long would you expect the card to
> make it as a hard drive knowing that the cards were designed with a
> limited number of writes possible, and also when the card reaches this
> point, is it readable-only then?  Mine can't even be accessed now.
>
I'm not sure what the failure mode is there.  I ruined one by hooking up
an IDE interface backwards...
> It seems to me that more and more people are trying to use CF cards as
> hard drive solutions for embedded systems and even for their
> computers.  This has got to be the business to get into?  :)  Think
> about it, they've designed a card that really shouldn't be any
> different than a memory stick in what they do (store memory and read
> it), but for some reason the CF's have a dying day somewhere in the
> future, sooner or later, depending on your use.  
I believe the limited writes are a feature of all flash memory, not just
those packaged in the CF format.  It should hold true of USB memory
sticks as well, it's just that CF has an IDE-compatible interface and
command set, so it is much easier to use in place of a hard drive, in
scenarios where it is likely to get abused.
> They know very well that people are trying to use them as hard drives
> on various systems, and that unless it's an embedded solution like
> Windows has done with a version of CE to limit the # of commits to the
> card, it's a dead card the day you buy it.  I don't think they're
> worth messing with.
>
For what you're trying to do (run an OS with virtual memory) you might
be better off using a Microdrive instead.  These have been made by (at
least) IBM, Hitachi, and Seagate.  They are tiny hard drives in the same
form factor and interface as a CF card.  They are a little thicker, so
make sure your card slot can accept a type II card.  Otherwise, they
plug right in.  Also, they take a little more power than a CF card, but
on your IA that shouldn't be a problem.  Geeks.com has some refurb 4 and
5 G Microdrives in stock for $10-$15: 
http://www.geeks.com/products_sc.asp?cat=377  Get one of those bad boys
and you shouldn't have to worry about too many write cycles.

JCE
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