the target still is in MSG OUT phase. We still send a message (a NO_OP)
in this case and the chip will remove ATN at the appropriate time.
Using the RSTATN command here induces a "illegal command" in some
chip revisions.
This situation only occurs if the target rejects a previous (multi-byte)
message early (by switching to MESSAGE IN and sending a MESSAGE REJECT)
before the chip has completed the entire MSG OUT transfer. ATN will
remain asserted, and the target returns to MESSAGE OUT phase.
* Account for the events above when reporting "DMA not completed"
diagnostic messages.
* Stream-line the selection code a bit, and make the DMA setup code
more like the MSG OUT & DATA XFER setup.
09559070f7