>> > Well, the Cyclades cards use a chip which only has 12 bytes of FIFO for
>> 
>> Ouch! That's less than a 16550. Perhaps that explains why the
>> Cyclades card was cheaper than the 8-port (and even some of the 4
>> port) 16550-based boards I've seen.
>
>Dunno.  The automatic hardware handshake makes the Cyclades better than a
>normal 16550, IMHO.

Only if the Cyclades is talking to something that can stop output before
sending more than a few more characters.  E.g., if flow control is invoked
when the input fifo has 8 characters in it, then the sender must not send
more than 12-8 = 4 more characters.  If the sender is a 16550, which can't
reasonably stop without sending up to 16 or 17 more characters (its full
transmit fifo size plus one for its shift register), then flow control
would have to be invoked when the input fifo has 12-17 = -5 characters in
it to work :-).

Bruce