Thats not how I read it, admittedly not in the desparation you must be reaching now.

It looks like you get nothing back from the first three writes, then you write a channel number and get the data, unless you are in autoscan mode, when you write out 0700H and get channel 0,1,2,3,4,5,6 or whatever.

And the data is clocked out by the incoming data ?

Steve