Serial ports - how to get them to coexist peacefully...

["hogan" <hogan@netspace.net.au>]

P133, 48MB RAM, Debian Testing/Unstable (some bits from unstable) 2.2.17 (move
to 2.4.1 on hold for time being whilst I read Rusty's howtos on netfilter etc.
:) ).

Have two onboard ports - ttyS0 and ttyS1 (IRQ 4&3 respectively)
Have an ISA IO card (everything disabled on card save ttyS3 and "lpt3" [dunno
linux equiv] - reason for ISA - only have half slot, full and VLB IO cards in
"stockpile" :) )

Have modem on ttyS0
Switch between mouse and Wyse60 terminal on ttyS1
Want mouse on ttyS3 but IRQ conflict ttyS1+ttyS3

Can I make the onboard and oncard ttyS's play nice on same IRQ?
... or should I play musical jumpers until they're on separate IRQs?

Read something in 2.4.1 kernel config about making serial ports nice to one
another when on same IRQ.. anything similar in 2.2.x? Should I go to 2.2.18 in
interim? Will I need a custom compile? ... Will Danger Mouse save Penfold in
time? :)