Exsys EX-4044I - Multi port serial card - Fifo RS-232 - Linux

The problem

I am using serial ports quite heavily. My motherboard has two serial ports. I bought a cheap card with two additional serial ports (and one additional parallel port which i did not use). That card had no FIFO for the ports and these four ports were not enough for me altogether. That is why i was looking for another expansion card for my computer. I bought the above mentioned card, not knowing if and how it would work under LiNUX.

As i now found out and my card is running without any problems - i thought i should tell others. That is why i made up this small howto-page.

The card

Jumper Setting

There are two jumpers needed to determine the IRQ sharing. First, set the jumper at the single place on the board. It enables the irq sharing. I am using interrupt #7 for the four ports on the card. Second, set one jumper to the appropriate irq that you want to use. This line is labelled INTERRUPTER.

This means, that there are six jumpers used on the card to determine everything you need for interrupt sharing. That looks like this:

                              I I I X I I I I I   X
I I I X I I I I I I I I    I I I I I I I I I
I I I I X I I I I I I I    I I I I I I I I I
I I I I I I I X I I I I    I I I I I I I I I
I I I I I I I I X I I I    I I I I I I I I I

              I : no jumper at this location
                 X : jumper at this location

How to tell LiNUX about those ports

1. Log in as root.
2. Suse Linux before 7.0
   • Make a backup of the file /sbin/init.d/serial
   • Open the file /sbin/init.d/serial in an editor and find this section:

         ###############################################################
         #
         # MANUAL CONFIGURATION
         #
         # If you want to do manual configuration of one or more of your
         # serial ports, uncomment and modify the relevant lines.
         #
         ###############################################################
       

   • Behind this, insert the following lines:

         run_setserial /dev/ttyS2 uart 16550A port 0x3E8 irq 7 fourport
         run_setserial /dev/ttyS3 uart 16550A port 0x2E8 irq 7 fourport
         run_setserial /dev/ttyS4 uart 16550A port 0x268 irq 7 fourport
         run_setserial /dev/ttyS5 uart 16550A port 0x240 irq 7 fourport
       

   • Save the file and reboot.
3. Suse Linux 7.0 and later
   • Make a backup of the file /etc/init.d/boot.local
   • Open the file /etc/init.d/boot.local in an editor
   • Insert the following lines:

         setserial /dev/ttyS2 uart 16550A port 0x3E8 irq 7 fourport
         setserial /dev/ttyS3 uart 16550A port 0x2E8 irq 7 fourport
         setserial /dev/ttyS4 uart 16550A port 0x268 irq 7 fourport
         setserial /dev/ttyS5 uart 16550A port 0x240 irq 7 fourport
       

   • Save the file and reboot.
4. After the boot, you should be able to use the new serial ports. You can test each port with the setserial command (as root). It should look like this:

       root@computer:/home/root > setserial /dev/ttyS2 -a
       /dev/ttyS2, Line 2, UART: 16550, Port: 0x03e8, IRQ: 7
               Baud_base: 115200, close_delay: 50, divisor: 0
               closing_wait: 3000, closing_wait2: infinte
               Flags: spd_normal Fourport skip_test
   
       root@computer:/home/root >
   

What do i need all these ports for?

Standard Disclaimer

As always, this description worked fine for me. I can't tell if that will work on your computer too. I am not taking any responsibility for anything that goes wrong on your computer, neither hardware nor software. I your computer gets messed up - i am sorry but not responsible!