serial i/o broken and fixed

[Larry Williamson]

I've seen a lot of complaints with respect to microport's
inability to handle serial traffic.  I thought I had a
similiar problem a couple of weeks ago.  It seemed that 'all
of a sudden' my usenet feed stopped working.  When I called
my feed site, uucico would startup the transaction, but as
soon as the first file started to come in to my machine, the
connection would fail.  After about 12-22 alarms, the
connection would be dropped. 

For quite a while I hunted for the cause.  In the end it
turns out that the culprit was a serial line that had been
disconnected at the terminal end.  Someone had simply
disconnected the terminal and left the serial line dangling. 
I assume that there was an indeterminate condition on one of
the control lines that caused getty to continually send it's
prompt to this non-existant terminal. 

I found the problem when I noticed that the getty on this
line was using an incredible amount of cpu time.  In fact,
all available cpu time was being used by this getty. 

As soon as I disable this line, my 2400 baud usenet feed
returned to normal. 

My conclusion is that at least in this case, there was no
bug in the microport code, only my system configuration was
a mess. 

-- 
Larry Williamson                      Focus Automation Systems
UUCP: watmath!focsys!larry    608 Weber St. N, Waterloo, Ontario N2V 1K4
                                          +1 519 746 4918