I asked about experiences with multiport serial board and where they
can be purchased recently. I received many requests to pass on
whatever information I got, and I even got a little bit of
One person has a very cheap 4 port card designed for Xenix which
works. I don't know which board.
I found out that the Usenet Serial Board II is $255 (US) without
cables, which add $30 to that price. This is a 4 port board with
16550 UARTs. You can find out more than you ever wanted to know about
it by anonymous ftp. Look in pub/serial on nuchat.sccsi.com. While
this sounds like a nice board, it is very expensive.
The Boca 4 port board has a list price of $199, the 8 port $279, with
cables. I was quoted $108 and $165, plus $9 shipping and handling, by
Modern Age Consultants. You can e-mail me for further details.
I bought the Boca 8 port board, the BB1008. (the 4 port is the
BB1004) It, like the 4 port version, uses chips with the equivalent of
4 16550s in them. It has a 5 year warranty and was made in the USA.
It also appears to be well made. The board looks good and, get ready
for a shock, the jumpers are actually labeled. The cabling consists
of 8 RJ-11 type jacks on the back of the card, 8 6-foot cables, and 8
RJ-11 to DB-25 adapters.
The default I/O addresses worked fine for me, but the default
interrupt conflicts with one of the standard serial ports. I changed
it to int 5. (Int 5 is traditionally the second parallel port, isn't
it?) I recompiled the kernel with #define CONFIG_BOCA at the top of
kernel/chr_drv/serial.c. That belongs in linux/config.h, I guess, but
I'm lazy. I also changed the interrupt in serial.c to 5 from 12, but
you can use setserial to do that if you like. Linux now finds the
board at boot time, and the ports are /dev/ttyS16 through /dev/ttyS23,
which have major number 4, minor numbers 80 through 87. I haven't
been able to test extensively yet, but it appears to work fine. I
connected 2 ports by null-modem, ran getty on one and successfully
logged into the system through the other, for example. I'm going to
be attaching a terminal when I go back to school this fall, and
probably some other computers.
You can e-mail me if you have further questions.