March 4, 2018

Koha Configuration

Once you’ve installed Koha, you’ll need to do some configuration in Koha itself to get ready for use in a library. All of this can be done in the staff client, so log in with the same user name and password that you used to log in during installation.

March 1, 2018

Adding Undo and UTF-8 support to MicroEMACS

I’ve been hacking on the original Conroy version of MicroEMACS for over thirty years, and every so often I add new features that I need. In the last dozen or so years I added support for ctags, cscope, and Ruby on Rails (the latter very minimally). But for many years I’ve been wanting an undo function, and the ability to view and edit UTF-8 text files.

February 15, 2018

Mac OS Sierra and secd hogging CPU

A friend with a 2011 Mac Mini running Mac OS Sierra was complaining that the machine was running very slowly. Was the machine too old and needed to be replaced by a new one? Was the problem due to opening large numbers of tabs in Firefox? I was skeptical that either of these was the problem. My ThinkPad is even older (2008), has similar specs (Core 2 Duo processor, 8 GB RAM) and is plenty fast (Linux shouldn’t be much different from Mac OS in this regard).

February 1, 2018

Bloated Web Pages

Parkinson’s Law states that “work expands so as to fill the time available for its completion”. Corollaries to this law apply to most areas of software development. For example, the memory required for a program typically expands to fill the space available. This is especially true in embedded systems where code is placed in ROM. We could probably formulate a newer version of this law for the World Wide Web, relating average internet speeds to web page size.

August 9, 2017

Converting from Mandarin M3 to Koha

I wrote previously about Koha, an open source library system that our little (24,000 book) library in Vermont is now using. Before we switched to Koha, we were using Mandarin M3. This is a proprietary system that is accessed primarily through a Windows application that connects to a database server hosted by Mandarin. The system worked fairly well, but there were a number of problems and annoyances (not to mention pricing) that pushed us to move to Koha. But migrating our catalog, patron list, and checkout information to Koha was a challenge, and we didn’t want to do it manually, which could take months. I ended up writing some Ruby scripts to perform these tasks.

June 20, 2017

Infinite recursion in Rails associations

I’m working on a Rails 5.0 project that is using an existing database. This kind of project is more difficult than creating a database from scratch using Rails migrations. One problem is that the existing database doesn’t use Rails conventions for the names of its columns. That led me to a bone-headed mistake in my model associations that caused Rails to get into an infinite recursion.

May 30, 2017

Unblock sound on resume in Linux Mint 18

On the ThinkPad T60p and T61, using both Linux Mint 17 and 18, sound is not properly initialized after a suspend/resume cycle. The symptom is that after a resume, playing a video on YouTube produces no sound. The fix is to play a sound file using the /usr/bin/play utility, which apparently unblocks or reinitializes the audio device.

March 18, 2017

KVM on Linux Mint 18

I’ve been running Koha on Debian 8 in a VMware Workstation virtual machine, to test it prior to deployment on Linode for a real library. Yesterday I decided to investigate running this VM in KVM, the native Linux virtualization system that is used at Linode. The conversion went well on both Linux Mint 17 and 18. What follows are the steps I used on Mint 18 (Mate edition).

March 10, 2017

Pandoc on Linux Mint 18

As mentioned earlier, I use Pandoc instead of a word processor to prepare printed documents. Installing it on Linux Mint 18 reminded me that in order to create PDF files, you need to install more than Pandoc itself. Here is what I had to do to install Pandoc and the Latex files it requires:

sudo apt-get install pandoc lmodern texlive-latex-recommended \
                     texlive-latex-extra texlive-fonts-recommended

← Archive