In praise of arandr

I really like KDE's visual display settings module, but it lacks a profile saving tool. 

Last Friday I had to give a rather important presentation in an extremely time constrained setting and I had to rely on KDE kind of magically remembering the settings (side by side with the second display/projector on 1024x768) from the speaker ready room after removing the cable. (yay, open source, by the way - Windows and Mac users were fighting aspect ratio and resolution problems left and right…)

Enter arandr to the somewhat belated rescue (in the standard repos). Not quite as pretty as the KDE original, but a very capable xrandr graphical front end that has the capability of saving settings as xrandr shell scripts, e.g. my presentation mode as:

#!/bin/sh
xrandr --output HDMI1 --mode 1024x768 --pos 1920x1080 --rotate normal --output VIRTUAL1 --off --output DP1 --off --output eDP1 --mode 1920x1080 --pos 0x1080 --rotate normal --output VGA1 --off

So next time, I'll just have a nice folder view on my desktop with the PDF right next to the shell script:

Zenbook UX31A battery replacement

Not as easy as the snap-and click replaceable units on older laptops, but pretty reasonable for a built-in.
Equipment:

• C22-UX31 ASUS battery or a generic equivalent. (I got one off Amazon Germany for about 70€)
• T5 Torx screwdriver
• small Phillips screwdriver (#00, I believe)
• small spudger, flat screwdriver or other prying tool

 Remove the 10 Torx screws holding the bottom cover. The two at the back edge of the device are longer (blue circles in the image on top). Take out the 3 Phillips screws holding the battery in place (red circles).
The battery's board connector is a bit tricky, as it's snapped into its plastic jack by the two small  knobs marked by red arrows in the image below without any lever mechanism. Carefully pry the jack open with a small flat tool and remove the battery. Do everything in reverse with the new battery, charge for a few hours and enjoy.

Notes: As the Zenbook is flat enough to be used as a meat cleaver, the interior is extremely compact and well organised. Also, that tiny bar under the SanDisk sticker is the SSD. Should have guessed, but was still shocked (Also, it's more or less proprietary. Bad news if it ever breaks down).
We took the opportunity to clean out the fan with canned air, but there was hardly any dust even after 18 months of sloppy use. Probably due to the fact that the laptop gets a lot of passive cooling via the metal body and every opening is mesh covered from the inside.
Not so impressed by the original battery performance. I still get about an hour of use out of it, but it tended towards shutting the system down without warning at about 50% nominal charge.

Kile, biber and path issues on Precise

I've grown to like biber as a bibTeX backend, as it's highly configurable. However, it was a bit of a stretch to get it to work on my work computer, which is on Kubuntu Precise LTS.

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.