>Why is it impossible for multiple (standard) serial ports (ttyS?) to
>use the same IRQs?
>
Hmmm... I think I'll leave the answer to THE guru. Find some document
called The_Serial_Port, or The.Serial.Port. Its written by a guy called
Chris Blom, who known maybe more about PC serial hardware than anyone.
>If I remember correctly, I once did smth like this when I used DOS.
>Is it some hardware limitation or what? When an interrupt occurs,
>serial driver could look up which port it was meant for, couldn't it?
I dont think you used 2 serial ports on the same IRQ at the same time on any
PC :), and you are right it is a hardware limitation, and you are also right,
about it beeing possible for the serial driver to look up what port sendt
the interrupt, but that would also require a hardware hack on your seral
card(s). If you are interrested in serial ports on the PC, I strongly sugest
you read the above mentiond document, as it is a deffinet guide to what goes
on where, and why!
Best of luck
bardj