Here's the latest driver for the Cyclades Cyclom-8Y (and
Cyclom-16Y) asynchronous multiplexor.  After beta release,
it was discovered that any use of ports 4-7 or 4-15 was
causing ports 0-3 to stop operating.  I discovered that I
was improperly computing bases and offsets in some startup
code (which I guess was wedging the chips pretty hard).

The code, as packaged, contains some diagnostic code that
makes it look a bit crufty.  In addition, you can more
easily see where additional work needs to be done.  Perhaps
if you have some time...?

Anyway, it looks much better now.  I've done limited testing
of the Cyclom-16Y as well, so you've got more ports available.
The following script was used for testing.  It can be expanded
pair-wise for each external loopback established.  If you've
got a more complete test, I'd like to try it out.  (Note the
use of "nice" for the sender.  This appears to help the
receiver task from being swamped.  As it is, characters are
being dropped (or the line is throttled) if six or more
streams are in simultaneous operation.  I don't know if
"cat" is using a block read in this context, perhaps other
programs could perform better.)

    #!/bin/tcsh
    stty 19200 -echo litout cstopb < /dev/ttyC2
    stty 19200 -echo litout cstopb < /dev/ttyC3
    stty 19200 -echo litout cstopb < /dev/ttyC4
    stty 19200 -echo litout cstopb < /dev/ttyC5
    sleep 1
    (cat /dev/ttyC2    > out2; echo 2)&
    (cat /dev/ttyC3    > out3; echo 3)&
    (cat /dev/ttyC4    > out4; echo 4)&
    (cat /dev/ttyC5    > out5; echo 5)&
    date
    (nice +20 cat $1;sleep 1;echo )  > /dev/ttyC2 &
    (nice +20 cat $1;sleep 1;echo )  > /dev/ttyC3 &
    (nice +20 cat $1;sleep 1;echo )  > /dev/ttyC4 &
    (nice +20 cat $1;sleep 1;echo )  > /dev/ttyC5 &
    wait
    date

Randolph Bentson
bentson@grieg.seaslug.org
+1 206 282 8375
