Is there an easy way to list all devices on an IRQ?

Yes. It's kind of a hidden feature in the Device Manager. It's sort of stupid the way they make you do this, I wish it were more obvious. When someone pointed it out to me (on this very BBS if I recall correctly), I was pretty upset about it:

At the very top of the device manager tree, is the computer itself. On my system, it's called "Computer". Double-click on that. This gives you an ordered IRQ list.

See what I mean? Pisses you off when you see it. Totally non-intuitive way of getting that information.

Didn't try hyperterminal, got a more severe problem at the moment - the display doesn't not come up at all - totally blank. I have a note to carsupport, but suspect it's a defective unit.

This is probably a side-effect of the failed kernel flash. Re-flash it on the working laptop.