How does Dev.ser detect the IRQ?

My curiosity has got the better of me. The documentation to Dev.ser states
that it automatically detects the UART’s IRQ. I’d just like to know how this
is achieved. If the system is only ISA or PC104 there can be so information
to be gleaned from the bios.

Yours

Julian Thornhill

“Julian Thornhill” <jth@ion.le.ac.uk> wrote in message
news:askmil$840$1@inn.qnx.com

My curiosity has got the better of me. The documentation to Dev.ser states
that it automatically detects the UART’s IRQ. I’d just like to know how
this
is achieved. If the system is only ISA or PC104 there can be so
information
to be gleaned from the bios.

I think the documentation is wrong.

Yours

Julian Thornhill

“Julian Thornhill” <jth@ion.le.ac.uk> wrote in message
news:askmil$840$1@inn.qnx.com

My curiosity has got the better of me. The documentation to Dev.ser states
that it automatically detects the UART’s IRQ. I’d just like to know how
this
is achieved. If the system is only ISA or PC104 there can be so
information
to be gleaned from the bios.

Well, talking about UARTs for PC, it’s not so hard to determine which serial
ports are available, what version of UART is used (8250, 16450, 16550A etc)
and which interrupt lines they use. Time ago i wrote a code to do this first
for DOS32 and next moved it under QNX4. If you wich i can send it to you.
Some kind of “sertrap” utility.

Anyway you can always check code of Dev.ser available at
ftp.qnx.com/usr/free/

// wbr