From: utzoo!decvax!harpo!utah-cs!utah-gr!thomas
Newsgroups: net.unix-wizards
Title: Re: DZ-11 vs DH-11
Article-I.D.: utah-gr.557
Posted: Tue Sep 14 09:14:39 1982
Received: Wed Sep 15 04:23:22 1982
References: ittvax.437

Ken O's comments about DH inefficiencies on Vaxen do not apply to the 4.1bsd
operating system.  Why?  Because the DH driver PERMANENTLY allocates a piece
of Unibus map which points to the clist area.  Thus, there is NO overhead
of setting up the Unibus map for DH DMA output.  There is still the normal
overhead of setting up the DMA transfer, but this is small.

=Spencer