Date: Thu, 29 Jun 2000 14:15:48 -0700 (PDT) From: "Peter C. Wallace" <pcw@mesanet.com> To: freebsd-small@FreeBSD.ORG Subject: Re: oversized floppies for picobsd? Message-ID: <Pine.BSF.4.20.0006291353090.7438-100000@freeby.mesanet.com> In-Reply-To: <00062914395322.00531@tyr.dreamwvr.com>
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On Thu, 29 Jun 2000, dreamwvr wrote: > Hi, > What CF hw manufacturers work seemlessly with BSD, and Linux and ideas? > TIA > dreamwvr@dreamwvr.com Since in the IDE mode they have to look like a hard drive, I would think they all should work. I have used SanDisk and Simple Technologies and had no troubles, neither have I had trouble with our on card flash using a TEL (well now Toshiba) controller chip. > > In message <Pine.BSF.4.20.0006291110000.7261-100000@freeby.mesanet.com> "Peter C. Wallace" writes: > > : I agree, we use 'embedded' CF (a CF controller chip and memory on > > : the on CPU card itself) on some of our CPUs. Since they look like just an > > : IDE drive, no special drivers are needed. Also CF is a mass market item so > > : there is lots of competition keeping the price low. Also, good CF using > > : NAND flash and ECC can support millions of writes, probably better than > > : the media life of a floppy... > > > > We've yet to wear out a CF (CompactFlash) memory card. We've broken > > two or three DOC2k chips, but I think that was the bad lot of them > > they got a while back rather than really wearing them out. > > > > Warner > Paraphrasing an example from a TEL controller (for NAND flash) book: MTBF(hours)= (#blocks*reprogramming cycles*reprogramable area rate)/(Number of sector writes per hour) for example when writing at an average of 32k bytes every five minutes into a 4M flash disk with about 30% free, the MTBF is (512*1e6*.3)/(64*12) = 200,000 hours. This can be improved by leaving more free space on the drive. So at moderate write rates, or all the manual updates you would care to do, there is not much danger of wearing out a CF disk... Peter Wallace Mesa Electronics To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-small" in the body of the message
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