uucp problems solved with hardware

Keith Packard keith at motel6.UUCP
Wed Mar 19 15:25:02 AEST 1986


To recap, I was having problems with uucp running on my PDP11/73 timing out
when receiving data at 1200 baud from a vax running ultrix.

The problem was identified as overrun errors in the dlv11-e card that
I had attached to my modem, this card has no buffering for data at
all.  Overrun errors were occuring because 2.9BSD spends too much time
at high priority handling disk i/o.  I find it difficult to understand
how it spends over 1/120 of a second at high spl handling such simple
activity but it is the case.

The solution I used was to get a dzv11.  This solved the problem completely
because it has a 16 character input silo which doesn't overflow.

If anyone cares, I modified the dz11 driver to support dzv11 cards
(which have only 4 ports per board) as well as make it support 
dialin and dialout on the same port (with correct interlocking).  I
realize that the original dz driver supported a device class that
ignored carrier, my hacks are suitable for sites which want to use
a given line for *both* dialin and dialout.

Keith Packard
...!tektronix!reed!motel6!keith



More information about the Comp.bugs.2bsd mailing list