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Pat, What is all this about -:? Besides Atapi Inquiry, what other commands have a variable length write or read (i.e. you get more or less than you requested) ? EVERY time I have ever seen this it falls into 1 of 3 bins: 1) Broken device (i.e. defective) 2) Bad software (i.e. Improper design) 3) Badly designed device (i.e. Improper design) Do properly designed ATAPI CD/DVD/CDRW devices do this (I have never seen it) ? If not, then make all other devices and drivers BEHAVE. BTW: I'm have no idea how you are getting anywhere near 17MB/s out of PIO with IN/OUT turn around times of a Pentium II and beyond. Just looking to be educated Jeff > -----Original Message----- > From: Pat LaVarre [mailto:[EMAIL PROTECTED]] > Sent: Tuesday, December 04, 2001 1:43 PM > To: [EMAIL PROTECTED] > Subject: [t13] a fix for imprecise UDma residue? > > > This message is from the T13 list server. > > > Hey everyone: > > Anyone clueful want to nominate an xA1 IdentifyPacketDevice > bit to fix this: to make SwDma/MwDma/UDma as capable of > precise byte counts as Pio? > > If the bit is set, then the device promises, in the x03 > StatusIn phase after some Dma data moved out, to set x1F5:1F4 > to the bytes it received but did not request. > > For example, if the host sent 514 bytes but no matter than in > Pio mode the device would only have requested 512 bytes, the > device would set x1F5:1F4 = x00:02. > > If the host sent 8 bytes but in Pio mode the device only > would have requested 7 bytes, the device would set x1F5:1F4 to x00:01. > > Good/ bad/ confused idea? Please comment. > > Thanks in advance. Pat LaVarre > > > Subscribe/Unsubscribe instructions can be found at www.t13.org. > Subscribe/Unsubscribe instructions can be found at www.t13.org.
