ATA/ATAPI question

[domu]

I am trying to figure out what exactly is happening
on ATA/ATAPI bus right after power-on. From what
I understand - host shoud send RESET command, then
after some predetermined time send query to identify
devices on the bus. But in reality, it does not look
much like that. I have connected logic analyzer, and
from what I see there are flying some READ commands
before any WRITE (to send a command) happen. Why ?

Anyone know/understand what should be the actual
sequence of events ?