ESIX- Additional Serial Ports?

[John Temples]

In article <1990Aug11.115912.10530 at pegasus.com> richard at pegasus.com (Richard Foulk) writes:
>> [...]              BTW if you have Rev D of ESIX it will
>>make use of the 16550 FIFO chip if you have it.
>How does it compare to the FAS driver?

I can't say how it compares with the FAS driver, but I did a quick
benchmark and found that the ESIX driver runs *much* faster with a
16550.  I just installed a DigiBoard DigiCHANNEL PC/4 board on my
ESIX system.  This is a dumb four-port card with socketed UARTs.
It's directly supported by ESIX's asy driver.  I replaced one of the
16450's with a 16550A.  I connected a Wyse 50 terminal to the 16450
port, logged in at 38400 baud, and did 'cat /etc/termcap'.  u386mon
running on the console, with the system otherwise idle, showed 40% to
45% CPU utilization on my 33 MHz 386.  Doing the same test on the 16550
port showed 6% to 10% CPU utilization.  I think I'll be buying some
more 16550's...
-- 
John W. Temples -- john at jwt.UUCP (uunet!jwt!john)