According to David Hopper:
> 
> This has been hanging around since pre-1.0, and I forgot what the
> fix was.  I'm getting it frequently, every six or seven minutes.
> What does this error mean?  What can I do with ser.c to get rid
> of it?  My connection is at 38400, which should easily be handled
> by my A3000/040.
> 
> Thanks,
> David Hopper (bard@tiamat.chaldea.com)
> 

Here's the "fix."  But I think I recall this only works with certain
(scsi?) interface cards.  I have a stock A3000 and it works great
for me:

#
options         "SERIBUF_SIZE=16384"    # use a much larger serial input buffer
options         LEV6_DEFER              # use level6 interrupt remapper