Showing posts from March, 2011

Old laptop can't read Windows 7 DVD

I recently tried installing Windows 7 Professional  (x86) on an old MSI Megabook S250. The laptop is an older 2GHz Centrino with 2GB RAM and an internal slim DVD burner.

My preferred method of installing Windows 7 is by using the official Microsoft Windows 7 DVD/USB Download Tool which lets you make a bootable USB Flash stick from an ISO image. I've used this method countless times and it has never failed me before, until I tried it on the S250. I enabled booting from USB in the BIOS and moved it up to first priority, but whenever I'd insert the Flash stick and restart, it would say "A disk read error occurred."

I then tried burning the Win7 ISO on a DVD and enabled booting from DVD in the BIOS. The laptop would try to read the DVD but fail and continue loading Ubuntu (which is what I had installed at the time). Once Ubuntu was loaded, it would continuously try to read the DVD but was unable to mount it or access any of the files. I though the DVD drive was broken an…

Earphones with Integrated Mics and Mobile Phones

Everyone knows the 3.5mm standard earphone/headphone connector. It's the one that looks like this:
Take a close look at that picture though and you'll notice those two are not the same. The white earphones have what looks like a standard 3.5mm stereo TRS connector. The black earphones however have a 3.5mm TRRS connector. TRRS connectors allow for stereo sound going to the earphones, but also for a microphone audio signal going from the earphones to the connected device. These are typically found in smartphone earphones such as the Klipsch Image S2m.
Not all TRRS connectors are the same though. The Motorola Droid for example uses the following pin layout (image courtesy of So from left-to-right we have 4 white strips. These are for the left-audio signal, the right-audio signal, the microphone signal, and the ground. The iPhone on the other hand uses a different TRRS connector pin layout: Here, the ground and microphone ports are switched. What this basically mean…