On October  6, you wrote:
> I hope to use NetBSD/VAX for the base of a Free-Net node, DZ-11s 
> are much more civilized than COM1: ... COM2: ... Oops out of 
> interrupts. This isn't nostalgia, its protecting ones sanity.

  Hey there...you might wanna look into a DH-11 series mux for your
serial lines, man.  The DZ's are nice but they'll kill your machine in
a hurry.  They spew an interrupt on every character in or out of the
board.  A DH uses DMA to plop the characters into a buffer and only
interrupts once in a while.  They should be almost as cheap as a DZ
now, too.  The one that I had the most experience with was the
DH-11AD, which had 16 serial ports with full modem control, and was a
standard 9-slot Unibus backplane full of boards plus a rackmounted
DB25 distribution panel.  Very nice mux indeed.


                            -Dave McGuire
                             Operations
                             Digital Express Group, Incorporated
                             mcguire@digex.net