I totally agree with Larry. There is so much that you can do with your computer in terms of logging and prediction, but I relying on it as the primary alarm system is a bad idea. MTBF for hard drives and other components on the laptop just are not high enough yet. I have a V-MAC alarm system from Datastar (http://www.datastarmarine.com/sentinel.html) which is self contained, but you can use a computer to display the information and respond to alarms. I'm taking it a step further and writing custom software to display the information how I would like and to provide other features that I want. The reason that I went with this system was exactly what Larry was explaining. My computer could completely die and it wouldn't effect the normal function of the alarm system at all. That's not to say that alarms can't be based on computers. Under the covers, there is a computer there some place. They are solid state embedded devices that are meant to run forever without intervention. The economic realities of the laptop market emphasize a different feature set than that of embedded controllers. IBM recently started selling a high capacity hard drive that is not meant to be left on 24/7, which was surprise to many people who bought it. It's these kind of component decisions that are made by your laptop vender that you're not even aware of that will end up causing you problems when you're anchored out in the Queen Charlottes and you just lost all engine, flood and fire monitoring. I remember someone on this list talking about using a laptop without a hard drive for monitoring systems in a military application. They were using Embedded XP and only loading a small subset of the operating system and their specific software. That sounds like an interesting approach. Expensive, but interesting. Mike Harrington Friday Harbor, WA M/V Meander