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This may seem redundant to some of you but Pat Lavarre (and others) have talked some about conditions when commands complete abnormally. There seem to be several reasons for this: * Device power is unreliable. Device resets in the middle of a command. BAD HOST. * Device thinks it has seen RESET- asserted. BAD HOST or BAD DEVICE or BAD CABLE. * Device timeouts the host and just "resets". VERY BAD DEVICE. And Pat has talked several times about various X-to-ATA/ATAPI bridge things. In this case I want to make sure that everyone understands that in the ATA/ATAPI world the thing on the other side of the cable from the ATA/ATAPI device(s) is the ATA/ATAPI host. Please note that the X in X-to-ATA/ATAPI is NOT the ATA host. The bridge thing is the ATA/ATAPI host. An ATA/ATAPI host is expected to follow the ATA/ATAPI protocols and have a design that is compatible with the ATA/ATAPI standards. I know from experience that some of these bridge things are not very good ATA/ATAPI hosts and they are extremely unreliable ATA/ATAPI hosts. They only work if the actual host places only a very lite workload upon them using the most simple command executions sequences. But in any case the ATA/ATAPI interface should not be expected to work unless both sides of the cable, device AND host, are implemented somewhat correctly. This means, for example, that a bridge thing should be able to detect when a command has executed correctly and when a command has transferred the correct number of data bytes, etc, ... all the same things an true ATA/ATAPI host usually can do with little problem. A bridge thing that just assumes the device will "do the right thing", and is therefore unable to detect strange device activity, is a bridge thing you do not want attached to your system... you certainly don't want it procesing any of your valuable data. *** Hale Landis *** [EMAIL PROTECTED] *** *** Niwot, CO USA *** www.ata-atapi.com *** Subscribe/Unsubscribe instructions can be found at www.t13.org.
