Author: Ben North

Braille in National Aquatic Centre lifts

I was wondering about the Braille signs in the lifts at Dublin’s National Aquatic Centre, and it turns out they are in German (courtesy of the Wikipedia entries on German braille and Braille patterns in Unicode): Open doors ⠞⠳⠗⠀⠡⠋ Tür auf Close doors ⠞⠳⠗⠀⠵⠥ Tür zu Alarm ⠝⠕⠞⠗⠥⠋ Notruf Curious. See also this xkcd (thanks to Oliver Nash for the pointer).

Continue reading

Raspberry Pi, Squeezebox, phone line

Motivation Long ago, I built a circuit which enabled a PC to monitor the phone line, and control the music system in our old house. Whenever somebody rang, it would pause the music, and announce the caller using voice synthesis. It was cool. Details are on a pre-blog page. Alas, when we moved house, the hardware got lost, and ever since, we have had to manually pause the music, and look at the tiny display on the phone to see who was calling. I had been meaning to reinstate the automatic system for ages; it had actually been quite useful. Photo © Flickr user GijsbertPeijsCC-BY-2.0 The other motivation for this project was as an excuse to play with the Raspberry

Continue reading

UK government consultation on Open Standards

Back in June, I submitted a response (also as pp.35–39 of a PDF on the Cabinet Office’s site) to the UK’s consultation on open standards in government. Today I received an email notifying me of the conclusions to this process. I have read through the UK government’s ‘Principles’ document, and the following snippets are quite encouraging: ‘Open’ includes ‘royalty-free’ I think the big one is the inclusion of ‘royalty-free’ in the requirements for a standard to be ‘Open’: 2. Open standard – definition … Rights – rights essential to implementation of the standard, and for interfacing with other implementations which have adopted that same standard, are licensed on a royalty free basis that is compatible with both open source and

Continue reading

An unusual primality test

A few years ago, I came across The Computist Quiz, and one question in particular led to some interesting mathematics: Amphibious Discursion A predicate on positive integers: boolean isToad(int n) { return ( (n == 2) || (n == frog(4, floor((n – 1) / 2), 1, 0) – 1)); } is defined with the aid of the following helper method: int frog(int q, int r, int s, int t) { if (r < t) return 0; else if (r == t) return 1; else if (q == 0) return 0; else return (frog(q, r, s + 1, s + t) + frog(q – 1, r – t, 1, 0)); } Which integers are toads? Describe what the frog method does.

Continue reading

MazezaM is NP complete

Update 20170129: My claim that Mazezam is NP-complete is not shown by this argument. The argument does show that Mazezam is NP-hard, but it is not clear that Mazezam is itself in NP. See a follow-up post for more details. Many thanks to Aaron Williams for contacting me to point out my error. The post about AutoFickle reminded me of something I did a good while ago (2008) which doesn’t currently have a home. The connection is that this is also a project based on a game written by Malcolm Tyrrell. The game this time is MazezaM, dated 2002–2004; in it you push rows of blocks back and forth, trying to get from the entrance to the exit of a

Continue reading

Ireland’s copyright consultation

Background Ireland’s Department of Jobs, Enterprise and Innovation are in the process of conducting a review of how copyright operates in Ireland. They published a consultation document and invited submissions. The Irish Free Software Organisation made a submission, which I drafted. There were also several points about the paper which I thought were interesting, but not strictly Free Software issues: Observations on the consultation paper Neutral phrasing 2. The Intersection of Innovation and Copyright in the Submissions […] 2.2 Innovation […] […] the established film, music and news industries have struggled to find successful business models in the face of widespread infringement of the copyright in their content. [p.5] Encouraging that they don’t use words like ‘theft’ or ‘piracy’ here.

Continue reading