[sebhc] list archive and a specific question
frustum at pacbell.net
Wed Jul 6 20:57:15 CDT 2005
Dwight K. Elvey wrote:
> Hi Dave
> If you are seeing errors, you have some type of
> issue that needs to be fixed. Are you using the
> checksum directly from the sectors on the disk
> ( may be a CRC ) or are you generating it from
> a RAM buffer? Like I said, I've never seen a problem
> without a cause. I have designed embedded systems
> that do CRC checking on packets of data that
> run continuously, 24/7. Any logged errors required
> repairs. I've, also, done over a 100 disks on my Poly8813 without
> a single missmatch.
> In any case, you should try using a CRC rather than
> a check sum. These can be used to find the error location
> for small burst of bit errors. I would suspect your RAM
> if the errors were always in the same location of your
> buffer. As a sanity check, you might try turning on
> the parity as well.
> Of course, if you are using Windows, such errors are normal.
Dwight, I have seen errors that weren't fixable. Say I'm transferring a lot of
data from my Sol to my PC, and there is no flow control. If I run at 9600 baud
and windows hiccups for some reason (it decides to kick off a virusscan or
something and that one task hogs resources for a couple of seconds), characters
get dropped. It is stupid that a 2 GHz machine can't keep up with a 9600 baud
channel, but it happens.
(I know, don't run windows, but for all of its flaws, it has some nice
properties too that, for me, make up for the heartburn)
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