On 28 May, James Lothian wrote:

> Ah. For the MXV21, formatting works the same as media density
> setting, except that the keyword you load into the data buffer
> register is 222 (octal) instead of 111. The format operation
> automatically does a set media density as well.
BINGO!
>>>d/p/w 20001E78 109
>>>d/p/w 20001E7A 92
And the controller starts to format the medium. 

After ragge enlightened me about QBus memory mapping I was also able to
do DMA from / to the controller and reading / writing sectors.

OK. The first step towards rx(4) is done.
?! There is already a rx(4)!? It seems to be a residuum from long gone
4.2BSD days. [looking at the 4.2BSD source] Indeed, there is a
src/sys/vaxuba/rx.c, without copyright notice...
-- 



tschüß,
         Jochen

Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/