old interne modem (ISA)

[Robin Gerard <robin.jag@free.fr>]

Hello,
I installed an old internal modem in my box :

my (old) box : 486 SX  OS = potato
my modem: Sporter Winmodem 56k

The modem works fine with win98 on COM3
With potato I use ttyS2 (in the BIOS I enable COM3)
but pppconfig (or wvdial) doesn't find the modem ?

However my external modem 3com US Robotics 56 k works fine
on ttyS1.
Can someone tell me what I forgot to do or which type of internal 
modem (ISA) works with linux. 

Thank you in advance for your help.
  
-- 
Gerard