[TriLUG] compactflash 64mb works, 256mb doesn't (rh 7.2)

[davis]

On Mon, Dec 08, 2003 at 10:12:48PM -0500, Rodent of Unusual Size wrote:
> davis wrote:
> > 
> > Are you using the same flash to pcmcia sleave in both cases?  I suggest
> > trying a different sleave.
> 
> yes, i was.  i went to best buy tonight and bought a newer pcmcia adapter,
> but no change in behaviour.  of course, the new one is also sandisk brand,
> just as the older one is.
> 
> > I worked on a similar problem an embedded board using microdrives and flash
> > cards.  One sleave in particular exhibited the same problem.  The fix for all
> > cards was changing a pull-up resistor on the pcmcia interface.
> 
> bugger.  on the laptop???

No not a laptop.  It was an embedded box.  If you bring your laptop to the next meeting, I will bring a different sleave which we can try.  For what its worth,
the flash card which had the problem was sansdisk.  It would not work with 
a sansdisk sleave or a radio shack sleave.  The only sleave which worked
with that that flashdisk on that particular platform was a IBM microdrive 
sleave.  The same flash disk worked with any sleave on a different different
embedded board. The line in particular was the wait/ready line on the pcmcia
controller interface.   A guy I was working with at the time had a software fix
where he ignored the wait/ready line, but I didn't like that fix because it
was defeating the purpose of the line. If worse comes to worse we can try that.
Don't know how it will effect other pcmcia cards though. 

What I expect is happening is that the controller has a marginal pull up 
resistor and that when you put the larger capacity flash card on the bus its 
causing a timing error because of the difference in load.  The result is that
it the device is not truly ready when it tries to be accesed.  I bet if you 
insert the card enough times, you will get it to mount ok.  

Now that I think about it, you can change the timing if you have the card 
already inserted in the slot when you load the driver and it might work.  
To test this either put the card in and reboot or put the card in and insmod 
the driver.  Once again, it won't do it every time.   


> 
> bah.  well, what other manufacturers are there for these adapters, and
> what alternatives might there be?  some sort of usb adapter, maybe?

No, just look at pricewatch. There has got to be many of them.

> 
> thanks!
> -- 
> #ken	P-)}
> 
> Ken Coar, Sanagendamgagwedweinini  http://Golux.Com/coar/
> Author, developer, opinionist      http://Apache-Server.Com/
> 
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> 
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-- 
Happy Trails	

John F. Davis
ABC #6334 1992 R100GSPD                    Durham, North Carolina
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