Since I have reported problems in the past with com.c running
a dedicated PPP line at 115200, and reading these very interesting
test results I wanted to report the result of the latest changes
to com.c on my system.

ibuf overflows have disappeared. This seems to be a result of the
changes in 1.61.  I am still getting quite a few silo overflows,
and I have determined that I can aggrevate the problem by passing
data over my Ethernet interface.

Related hardware:
i486/66 256 cache
Hayes ESP serial card
SMC Elite 16 Ethernet