Answering your other notes now - sorry for skipping them in my earlier
mail ;)
Chuck Guzis <cclist at sydex.com> wrote:
  On 12/10/2015 12:21 PM, Oliver Lehmann wrote:
  right - This is what I do in the code - I was
writing "from memory". 
 Just going by what you write...BTW, what are you using as a reference? 
I've used 
ftp://ftp.seagate.com/acrobat/reference/111-1c.pdf a lot.
Also other IDE implementations on ATMegas.
  PATA-6 is sort of a kludge supported by double-writing
(MSB first)
 to each of the address registers without any intervening access to
 any other register.  Intel employs this sort of thing on their older
 8-bit peripheral support chips. 
OK - but those drives should also work on non-PATA-6 systems but with
reduced capacity - right?
Oliver