I added the following to sysinit:
mount /dev/fd0 /fs/fd0
mount -T io-net /lib/dll/npm-qnet.so
But it won’t start at bootup. It tells me it cannot mount. What’s wrong?
sysint? Are you running qnx4 or qnx6? If qnx6, add it to /etc/rc.d/rc.local and see if that helps. If qnx4, there is no io-net, so that would probably fail. 
Rick…
The sysinit script (well, actually the device enumerator) starts io-net, so if you’re trying to mount Qnet before io-net has started, it isn’t going to work. Actually, if you want to start Qnet, you can create an empty file called /etc/system/config/useqnet. If sysinit finds this file, it starts Qnet for you.
The Neutrino User’s Guide (in 6.3 – soon available in print) has a chapter on controlling how Neutrino starts.
As for the floppy driver, have you tried specifying the type of filesystem? For a QNX 4 floppy, try specifying something like this:
mount -tqnx4 /dev/fd0 /fs/qnx_floppy
I hope this helps.