Determining if ISA card exists using user space driver.

["Hugh de Burgh" <h_deburgh@hotmail.com>]

I've been writing a user space driver for a proprietary ISA card for linux.I've used ioperm to give me access to the ports (using inw, outw) and mmap of /dev/mem to give me access to the memory.

This all works great if my ISA card is present.
But if it doesn't exist my code seg faults when I try to access the memory or ports which aren't there.

So my question is... how can I determine if the card exists or not without my code seg faulting?

Is this possible without writing a real kernal space driver?

Thanks very much,

-Hugh
(ps: I'm using g++ on Redhat 8.0)