On Sunday, June 8, 2003, at 09:33  PM, Henry B. Hotz wrote:

> At 8:32 PM -0400 6/8/03, Michael R.Zucca wrote:
>> 3. Do un-16-byte-aligned transfers under 4k by copying the data 
>> to/from a pre-allocated and aligned transfer buffer. This will help 
>> solve the sync negotiation problem by boiling it down to figuring out 
>> how to do odd-sized transfers that appear to be completely DMA.
>> 4. Figure out a way to do odd-sized reads/writes that will satisfy 
>> the sync negotiation code.
>
> Doesn't most of the disk IO occur in 512-byte increments from 
> page-aligned buffers?

During boot, there are some transactions occur that aren't aligned or 
of even size, or at least they don't seem to be. This may be some poor 
coding in the NCR code, but it does happen.

Experience seems to show that once the probing at boot is finished, 
most transfers are the size of a page or some multiple thereof, which I 
would expect.

-- 
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  Michael Zucca - mrz5149@acm.org
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  "I'm too old to use Emacs." -- Rod MacDonald
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