Jamie’s Blog

July 18, 2008


Filed under: ideas, technical, programming — rjmunro @ 2:58 pm

A few weeks ago I went to mashed. I used the opportunity to resurrect MusicBrainz’s Future Proof Fingerprint function, which I discovered had recently been ported to Java. I managed to automatically find when Jo Whiley played the same song in different shows. I didn’t win anything, but it was fun. I’ll get around to tidying and releasing the code some day.

Nice coverage of mashed was provided by the BBCs click online programme.

July 11, 2008

Cornwall double roundabouts

Filed under: transport, holiday — rjmunro @ 1:09 am

What’s with all the double roundabouts in Cornwall? Everywhere that a single roundabout would do, they seem to prefer to put two mini roundabouts instead. Sometimes I can see why they are needed because the roads used to meet at 2 T junctions, but a lot of the time, a single, larger roundabout would have done the job. In some cases it clearly used to before they changed the road. Maybe they work better, but they are confusing until you get used to them.

Interesting issue with a wireless router & cable modem

Filed under: technical, support, broadband — rjmunro @ 1:05 am

A friend of mine is using a wireless router connected to a cable modem to share internet access throughout his household. It worked fine for several months, and all the rest of his household and visitors could connect to the internet.

Then he reported to me that after his fridge broke down and blew the fuse in the electrical ring main, on restoring power the internet would function on his laptop, but not for any of the other laptops in the house. He hadn’t changed any settings - he was using his laptop wirelessly through the router, and that worked, but when others tried, it didn’t. I connected my laptop to the network, got issued an IP address and gateway by the router’s DHCP server as usual, was able to find and ping other machines on the network, but was not able to get any external connectivity. The external network couldn’t have been down, because my friend’s laptop was working. It was just everybody else’s that wasn’t.

After scratching my head for a while, and trying to fix the problem on my laptop, I decided to double check the settings on his laptop. Then I saw a strange thing. Despite him being connected wirelessly through the router, instead of having a local IP address issued by the router (like 192.168.2.nnn), he had the real IP address of the internet connection as issued by the ISP. Then I checked the cables on the back of the router. It turned out that the cable modem was connected to one of the LAN ports, instead of the Internet port on the router. As a result, all the computers wireless LAN were effectively directly attached to Virgin Media’s LAN with only a switch, instead of with a router.

When we set the system up, we had to register the connection using his laptop, then clone the MAC address in the router. The MAC address of his computer was therefore recognised by Virgin Media’s DHCP server, and it was given a valid external IP address and router, and worked, using the wireless segment as a bridge. The rest of the network formed it’s own subnet on the same cable using addresses supplied by the router, but could not get any external connectivity.

July 10, 2008

Alternatives to a third runway at Heathrow

Filed under: transport, future, ideas — rjmunro @ 12:46 am

The proposed Heathrow airport third has a lot of campaigns against it, but not many seem to be pointing out the alternative options available, concentrating instead on things like it won’t be necessary as people fly less when oil prices rise and greenhouse gases get curbed. These arguments fall down if biofuel or hydrogen powered jet engines come in. (Hydrogen powered jet engines were around and flying in the late 1980s, but seem to have disappeared since).

The best plan I have seen would be to link all major London airports by MagLev, using the TransRapid technology as developed in Germany and deployed in Shanghai. This would be about half the cost of the third runway, yet deliver huge extra benefits by creating a virtual “super airport” with 5 runways and 9 terminals. It would also provide benefits to the environment because rather than drive to the airport your flight leaves from, you could drive to the nearest airport and transfer in less than 25 minutes (worst case).

Another possibility I heard mentioned a few years ago when this issue came up, is to use Northolt as a sort of relief runway for Heathrow. Certain flights or Airlines could be moved there, and transferring passengers could take a short bus ride between the two airports.

Better than a bus would be an extension to the ULTra PRT system that is currently being installed between Terminal 5 and some car parks. If successful, the plan is to extend it to other parts of the Airport and surrounding infrastructure. An extension to Northolt would be a journey time of around 20 minutes. Because the vehicles are automated and individual, vehicles could keep land-side and air-side passengers separate, and special vehicles could be run to carry just luggage as an extension to terminal baggage systems. Stops could be added in Hillingdon, Hayes, West Drayton and Uxbridge for locals to use, which would be a popular means of transport, reducing car, bus and taxi journeys and should reduce NIMBY-type objections to the project being built.

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