Sven,

The PRDT is the Physical Region Descriptor Table. ...

Thanks.

It seems, however, that NO does not use virtual memory at all ...

Agreed. Otherwise we would have noticed it long ago.

If that's the case, you don't need the mentioned procedure,

Good. I'll continue. Regards, ... Peter E. Desktops.OpenDoc http://carnot.pathology.ubc.ca/