firewire audio interfaces + laptop: POWER SUPPLY?

[amarule]

I've several FW interfaces that I've used on battery power on Macs (both powerbooks and new macbooks) with no problem, but don't expect much in the way of battery life, maybe an hour on a good battery.

6 pin FW 400 and 9 pin FW 800 will buss power any FW device. 4 pin will not, it only carries data.

You can get a 6 pin FW card(PCMCIA) for any laptop that doesn't have one for short money.

This beats the crap out of USB2.0, which in most cases requires either using two USN ports (1 data 1 power) or a separate PSU. I've seen some USB devices that did manage limited workings on a single USB A connector, but were limited to i/o and sample rate without a wallwart PSU.