jan-jaap wrote:-ATM will make your head explode if you fail to fail to grasp the concept of packet switching.
I have only one machine with an ATM interface, so I can't comment. But somehow I expect the details of the implementation (packet switching) to be hidden by the tcp/ip stack.
Once an ATM network is set up, all the complexity is indeed generally hidden behind the TCP/IP stack, but hosts on ATM nets usually do require some driver tweaking and tuning.
However, getting an ATM network up and running can be much more complex and challenging than getting FDDI or ethernet running, regardless of the protocol which is going to run on it.
To complicate things further, getting good drivers for IRIX systems is a challenge, even with SGI-made network interfaces (the old Challenge L/XL ATM cards, for example). You'll often find cards that only have IRIX 6.2 drivers, or 6.3 drivers, or 6.4 drivers, or even 5.3 drivers, and for cards that have 6.5 drivers, they often have serious glitches.
For any hobbyist who wants to experiment with ATM, I highly recommend doing a lot of product research first and sticking as much as possible to a single hardware manufacturer for NICs and switches.