It's apparently manufactured by a company called National, model number: WH1050
This version doesn't have a computer interface, but I'm wondering if by any chance an upgrade is available that does. It does most of the things I'd want from a home weather station, although you have to wonder why they couldn't include some sort of wind direction indicator, but without some way of recording the data it isn't much use.
Unfortunately there are simply too many companies called national, and even with the model number I haven't been able to find out more. Does anyone recognize it, or know anything about them?