SCX-4200 on Ubuntu 13.10

The scanning unit of my trusty Samsung SCX-4200 multifunction printer used to be plug and play with a default Kubuntu but wasn't recognised by skanlite or sane-find-scanner after recent updates. Turns out I needed to install libsane-extras.

Broken Saucy update on a Zenbook

Confession: I did a somewhat rash Kubuntu Saucy upgrade while on holidays. It left me with a blank screen at startup. But what better entertainment can you have lying awake with a 6 hour jet lag at 4am than fixing your Linux?

The issue, by the way, is the Zenbook (UX31A) not liking the new kernel. The solution is Joseph Salisbury's inofficial kernel fix.

Amersham's .gel files: scaling issues

Phosphorimager plates are great for imaging radioactive gel emissions - they have a high dynamic range and linear response (Johnston et al., Electrophoresis, 11, 355 (1990)). Data values are read out by a laser scanner (a Storm 860 in our case) and stored in a .gel file, which is basically a TIFF file with a few extra private tags.

Ghostscript 9.07 is buggy

...it fails to convert PDF into page images with "Error: /undefined in --run--".
I downgraded to the Quantal 9.06 edition. Due to dependency issues, a number of packages have to be downloaded (e.g. from http://packages.ubuntu.com/quantal/ghostscript) and replaced:

sudo dpkg -i ghostscript_9.06~dfsg-0ubuntu4_amd64.deb  ghostscript-x_9.06~dfsg-0ubuntu4_amd64.deb  libgs9_9.06~dfsg-0ubuntu4_amd64.deb  libgs9-common_9.06~dfsg-0ubuntu4_all.deb

Prevent ghostscript from getting upgraded immediately with

 sudo aptitude hold ghostscript_9.06~dfsg-0ubuntu4_amd64.deb  ghostscript-x_9.06~dfsg-0ubuntu4_amd64.deb  libgs9_9.06~dfsg-0ubuntu4_amd64.deb  libgs9-common_9.06~dfsg-0ubuntu4_all.deb

The downgrade doesn't seem to affect programs depending on ghostscript like LaTeX or lilypond.

Alekto - dual booting a Zenbook

After Tisiphone, an Asus Bamboo U43JC, bowed out after 2 1/2 years with FUBAR hinges, a 3/4 working LCD panel and a dead battery, the natural choice was to stick to Asus, of course. In fairness, finding something ultraportable with a full metal body and decent screen resolution that's not a Macbook Air and doesn't break the bank doesn't leave you many options beyond a Zenbook. I went for the UX31A DB71 with a 256 GB SSD and i7 3517U processor.

Okular inverse search for multiple editors (e.g. Kile)

Setting up inverse search for Kile/Okular is well documented, e.g. in the official Kile docs. What has always bugged me, though, is that the inverse search editor is set globally in the okularpartrc config file, which means that you can't set up inverse search with different editors for different source code types.
I put together a workaround that changes Okular's editor choice to Kile when Okular is called from Kile by temporarily overwriting the okularpartrc file.