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> we have:
> BSY=0; DRQ=0 : HP2:HI0
> BSY=0; DRQ=1 : HP2:HP4
> BSY=1; DRQ=0 : HP2:HP2 
> BSY=1; DRQ=1 : ???

In a host's sample of x3F6 Alternate Status, or of x1F7 Status, seeing
BSY=1 makes DRQ indeterminate.

If the t13.org text tells the host to behave differently when DRQ=0 or
DRQ=1 seen together with BSY=1, then the t13.org text errs.

(Or else I've missed a significant backwards-incompatible change in the
standard.  I have not myself closely studied that text since I was last
responsible for complying with it, which was Spring of 1998.)

> "Host PACKET non-data and PIO data command state diagram"
> (figure 53 in d1532v2r4.pdf). I'm ignoring the overlapped modes,
> and I'm assuming nIEN=0.

Delightfully precise cross-reference, thank you.

Pat LaVarre
bc: [EMAIL PROTECTED]


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