Harry Wood Blog
type: channel
date: 2026-02-25T11:17:37Z
update period: hourly
update frequency: 1
update base: 2000-01-01T12:00+00:00
generator agent: https://wordpress.org/
items: OpenStreetMap Notes – SOTMEU Dundee talk
items: Repton puzzles and broken encryption
items: Door finger passing out
items: I’m no longer twitter domesticated
items: Job at Vivup
items: Oomph! Wellness
items: 2020 for me
items: Linear time calculator
items: Successfully spawning offspring
items: Open Data Camp

OpenStreetMap Notes – SOTMEU Dundee talk
type: item
creator: Harry Wood
date: 2025-11-29T18:30:22Z
subject: maps
description: I was at the OpenStreetMap conference State Of The Map EU in Dundee a couple of weeks ago. Lots of fun! Right at the end of the schedule, I gave a talk all about “OpenStreetMap Notes”. Below is a full textual transcript of what I intended to say, but you can now also watch my […]
encoded: I was at the OpenStreetMap conference State Of The Map EU in Dundee a couple of weeks ago. Lots of fun! Right at the end of the schedule, I gave a talk all about “OpenStreetMap Notes”. Below is a full textual transcript of what I intended to say, but you can now also watch my actual conference talk as a video The following slides are also available as the original LibreOffice ODP (76Mb) or as PDF (12Mb). Jump to slide: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 Slide 1 Hello my name’s Harry. I’m a long time OpenStreetMap contributor, and today I’m going to talk about “notes” Slide 2 Not this kind of “notes”…although. I do quite like talking about taking notes on paper. When I introduce OpenStreetMap to new people I like to point out that gathering data can involve mobile apps, cameras, GPS units or dictaphones, but it can be a simple as writing some notes on a piece of paper. …But that’s not what this is about! Slide 3 OpenStreetMap “Notes” is a feature on the openstreetmap.org homepage, over here on the right. If you click that, you can place a marker and add a little textual description of something which is wrong or missing on the map. For example imagine you live on this street and you notice your local cafe has here has changed it’s name, you might make a note like this. It’s a very easy way to contribute without needing to learn how to use the editors. You don’t even need to log in. Slide 4 The “Notes” feature started out around 2009 as this separate website called “OpenStreetBugs” created by user Xav and later re-built by user Emka. I remember looking at OpenStreetBugs and thinking “I wish I’d thought of that!”. It’s brilliant in its simplicity. A very simple interface to use, and a very simple thing to develop. The community used it on this separate site for quite a while, but we liked it so much, it was brought onto the main OpenStreetMap site (and bugs data moved over) i…

Repton puzzles and broken encryption
type: item
creator: Harry Wood
date: 2025-09-08T22:12:00Z
subject: Technology
description: My version of Repton running in its dinky window (watch video) I’ve been involved in a funny story of retro games and broken encryption going back several decades. In case you’re not interested in the Repton 3 game, I’ll skip ahead to… the broken encryption bit …because there’s an important lesson here. Do not roll […]
encoded: My version of Repton running in its dinky window (watch video) I’ve been involved in a funny story of retro games and broken encryption going back several decades. In case you’re not interested in the Repton 3 game, I’ll skip ahead to… the broken encryption bit …because there’s an important lesson here. Do not roll your own encryption! As a 19 year old computing student I’m not sure if I had yet started learning about encryption on my course, but either way I should’ve known better. I made a feature of my game, to allow creating “locked” levelsets. The intention was mostly to prevent cheating at the puzzles, but also to prevent opening the puzzles in the map editor. Not an ultra-secure encryption requirement, but I did make it scramble the file format, so that there was no easy way to unlock the maps by fiddling with it in a text editor. I thought I was being quite devious with various “scrambling” tricks, essentially re-arranging the bytes of the file with an algorithm only I knew about. Of course this is not proper encryption at all, but my naive younger self believed it would be enough to prevent anyone decoding it. At some point Gerald J Holdsworth figured out my file format. He’s created a repton map decoding tool, and even documented exactly how the scrambled file format works here! (page 41 “HW Repton 3”) “Each screen map is interlaced with each other, and the passwords, transporters, time limits and visible flag are interlaced with the map data. Also, the column and row order is interlaced. In addition, it is encoded with the lock password and a counter.” Oh yes! I remember doing that! I remember thinking I was being very sneaky. I never imagined someone would painstakingly figure out this encoded byte arrangement! How did he do it? I assume he did it with “known plain text” attacks, or in this case by crafting known repton map designs. This is generally the fatal flaw if you take this approach of trying to just algorithmically scramble the file a lot. So re…

Door finger passing out
type: item
creator: Harry Wood
date: 2025-03-22T20:54:01Z
subject: Uncategorized
description: I passed out again today. It’s happened before, and I blogged about it before back in 2006 and in 2008. Since then… There was the hospital occasion some time in the mid 2010s. I can’t remember if this was before or after getting married and having our first child. I had decided to go into […]
encoded: I passed out again today. It’s happened before, and I blogged about it before back in 2006 and in 2008. Since then… There was the hospital occasion some time in the mid 2010s. I can’t remember if this was before or after getting married and having our first child. I had decided to go into hospital worrying about chest pains (kind of a follow-up to that 2008 occasion). More tests, and this time they kind of answered the puzzle with the conclusion that it was probably a “sprained sternum”. But before that, one of the tests was a blood test, somewhat botched by medical students failing to find a vein, and it was that which caused me to pass out. Again, I felt like I’d been in a dream for a while. Curiously, I remember it being a particularly distressing dream in which I was wrestling to gather my thoughts. I came to with some more senior doctors looking concerned and the freaked out medical students in the background. Apparently I had been convulsing, but when I immediately started laughing, saying “Did I pass out? ok. Happened before” it probably set minds at ease. But if you thought blood test needles was a lame reason for passing out… Another half passing out happened during a conversation about teeth. I almost passed out in a restaurant with my parents, because my dad was talking about a gruesome cracked tooth injury he’d had. Suddenly I needed to go outside and sit down. I could feel myself going. With the fresh air and my head between knees, I managed to avoid passing out, but pretty weird that only talking about something could bring that on. And today? I slammed my finger in the door. A surprise gust of wind pushed the front door particularly hard and fast onto my middle finger. Several hours later it’s looking quite purple. Ouch! After swearing profusely and running it under the tap, I started to feel faint. Again a weirdly distressed dream about not being able to work out what I was dreaming about, and apparently I was convulsing again. Because of this, and b…

I’m no longer twitter domesticated
type: item
creator: Harry Wood
date: 2024-04-03T12:14:45Z
subject: Technology
description: It’s a weird time in technology and the web. It feels like a couple of big shifts are happening all at once. One of them is a big rise in “enshittification”, most noticeably for me with the death of twitter. It’s pretty surprising watching twitter die and, I’ll be honest, it’s upsetting. I allowed twitter […]
encoded: It’s a weird time in technology and the web. It feels like a couple of big shifts are happening all at once. One of them is a big rise in “enshittification”, most noticeably for me with the death of twitter. It’s pretty surprising watching twitter die and, I’ll be honest, it’s upsetting. I allowed twitter to become a bigger part of my online life than I should have done, and now it’s going down the toilet in a shift that feels quite sudden, given that I’ve been on twitter for about 16 years. Throughout 2023 I found myself gradually swapping from twitter to mastodon. Admittedly it wasn’t a very deliberate choice. I still go on both, but these days I think about posting to mastodon first and I’ll copy the post into twitter if I can be bothered. Why is twitter going down the toilet? (I refuse to call it “X” by the way) It took me a while to notice the problems, and maybe it was only the contrast with mastodon that helped me see it more. People talk in dramatic terms about nazis posts, which I never really saw, but there’s a shift in “the algorithm” of the feed. Mastodon only shows stuff from people I follow (and their re-toots). When I first played with mastodon a couple of years ago, it felt similar to twitter, but now twitter has shifted. It’s not even a subtle shift any more. My twitter timeline has very few posts from people I follow. Instead it’s full of clickbait videos and other “engaging” posts from non-followees. A lot of ads too of course. This algorithm shift is also noticeable with less engagement on my tweets. I see fewer likes and retweets these days. My tweets are hopefully not too dull, but they’re not exactly carefully engineered to “do big numbers”. They’re in a medium-interesting middle-ground which now seems to mean they go ignored more. And, before you roll your eyes at my dreadful narcissism, I know this is not just me. Others have said the same. If you’re guilty of paying attention to how many likes and retweets you get, then you’re probably noti…

Job at Vivup
type: item
creator: Harry Wood
date: 2024-02-04T16:50:29Z
subject: Technology
description: I started working at Vivup (vivupbenefits.co.uk). Actually I started there approximately one year ago, so in order to keep this blog bang up to date as ever… time to tell you about this! Vivup helps organisations provide benefits to their employees. We have many large government clients such as NHS trusts, local councils, police forces […]
encoded: <img loading="lazy" src="http://harrywood.co.uk/blog/wp-content/uploads/2024/02/vivup-logo-1024x709.png" alt="vivup" class="wp-image-900" width="375px" height="259px" srcset="https://harrywood.co.uk/blog/wp-content/uploads/2024/02/vivup-logo-1024x709.png 1024w, https://harrywood.co.uk/blog/wp-content/uploads/2024/02/vivup-logo-300x208.png 300w, https://harrywood.co.uk/blog/wp-content/uploads/2024/02/vivup-logo-768x532.png 768w, https://harrywood.co.uk/blog/wp-content/uploads/2024/02/vivup-logo.png 1054w" sizes="(max-width: 1024px) 100vw, 1024px" /> I started working at Vivup (vivupbenefits.co.uk). Actually I started there approximately one year ago, so in order to keep this blog bang up to date as ever… time to tell you about this! Vivup helps organisations provide benefits to their employees. We have many large government clients such as NHS trusts, local councils, police forces etc, and increasingly bringing in private companies too. The benefits on offer are many and varied. One part of the website is like a shopping site with all kinds of products available as a “salary sacrifice” purchase, paid for over many months. There’s lots of bicycles available via cycle-to-work schemes, and there’s store discount cards, and all sorts of health & wellbeing offerings. If these benefits sound good, you’ll have to arrange to sign your whole company up to Vivup! As you can imagine, it’s quite a big complicated website, and it’s a rails app! We have a tech team working on various aspects, including people focussed on the mobile apps, and the separate .NET bits. We also have people who are a lot more front-end focussed. They’re migrating more and more of the site to use React on GraphQL. Our sub-team’s focus is on the rails coding. There’s back-end aspects, the database and API integrations, plus a big back-office admin interface built with ActiveAdmin, and lots of interesting workflows and dataflows. To deliver improvements to all of this, we have quite a rapid pace of project…

Oomph! Wellness
type: item
creator: Harry Wood
date: 2022-05-10T15:06:17Z
subject: Technology
description: I was waiting for the right time to blog about my latest job. As it has now come to an end, I guess that’s overdue! So let me tell you about where I spent the past ~8 months: Oomph! Wellness. They’re a company providing training and content to care homes in the UK. Activities and […]
encoded: I was waiting for the right time to blog about my latest job. As it has now come to an end, I guess that’s overdue! So let me tell you about where I spent the past ~8 months: Oomph! Wellness. <img loading="lazy" src="http://harrywood.co.uk/blog/wp-content/uploads/2022/05/oomph-homepage.png" alt="" class="wp-image-836" width="476" height="324" srcset="https://harrywood.co.uk/blog/wp-content/uploads/2022/05/oomph-homepage.png 951w, https://harrywood.co.uk/blog/wp-content/uploads/2022/05/oomph-homepage-300x204.png 300w, https://harrywood.co.uk/blog/wp-content/uploads/2022/05/oomph-homepage-768x523.png 768w" sizes="(max-width: 476px) 100vw, 476px" /> They’re a company providing training and content to care homes in the UK. Activities and exercises for old folks! They’re not a tech company, or at least not until recently. For many years they’ve been doing face-to-face service provision, with teams of people going out to care homes to train staff in how to run activities and exercises. Another service involves sending bus drivers to take residents out on trips. And then there’s a third service “Oomph on-demand” providing activities and exercise related content on the website by subscription. This side of the business has been expanding rapidly, particularly during the pandemic lock-downs. By “content” I mean videos, or just written instructions/inspiration on activities. Also things like puzzles. There’s quite a variety, and they’re constantly building it into an extensive library. The nice thing is that they’re drawing upon all their experience of working in care homes, and it really shows. That kind of grounding in the real world is something that is so often missing in tech up-starts, and of course their past work gave them a foot in the door to sell this web-based service to many existing clients. So it’s a low-tech company transitioning into a subscription web content company. In fact they’d made that transition and were already selling on-demand subscriptions on a s…

2020 for me
type: item
creator: Harry Wood
date: 2021-01-01T23:58:55Z
subject: kids
description: 2020, the year of the virus, has been pretty alright for me actually. For me it was never going to be a normal year, with a new daughter arriving in January. By comparison the virus …well it’s a big deal, but impacted me relatively lightly. The wife planned to be on maternity leave for a […]
encoded: 2020, the year of the virus, has been pretty alright for me actually. For me it was never going to be a normal year, with a new daughter arriving in January. By comparison the virus …well it’s a big deal, but impacted me relatively lightly. The wife planned to be on maternity leave for a full year, expecting lots of quiet mother-daughter bonding time. Instead she’s had to put up with me working from home. During that first lockdown, the 4 year old little terror was at home too. I remember a period of a few weeks where the virus was pretty big news, having clearly arrived in the UK, yet still not quite impacting anyone significantly. Then suddenly things moved fast. My company decided we’d all work from home. At the time it seemed very cautious on the part of my employers (OpenCorporates) and I suppose it was a nice expression of care towards employees. But as it turned out, it was only a week ahead of everyone being told to work from home (first lockdown). It was a relatively easy transition for us, since we’ve always been geared up to do our software development work from home. Just a matter of getting used to the whole team being at home the whole time. We’ve since ditched our office and gone remote-only, as I’m sure many companies have. I remember some friends laughed off the virus as an overreaction at the early stages, and I did begin asking myself a question which I can’t help keeping in the back of my mind: “Will history remember it as an overreaction?”. There’s a paradox. With a multiplying virus we need to take aggressive measures before they seem necessary. If they work, they won’t seem like they were necessary. I don’t envy decision-makers dealing with that lose-lose choice. My twitter feed is full of people either explicitly advocating stronger measures, or expressing worries about the virus (which implies we should respond more aggressively). I think that’s right, however I can’t help also thinking ahead to a time in the future where we will all look ba…

Linear time calculator
type: item
creator: Harry Wood
date: 2020-09-04T21:42:17Z
subject: Technology
description: I keep doing the same calculation over and over again, so I decided to make an online tool specially for it: >>> Linear time calculator <<< It’s a simple enough calculation to work out a time estimate for something based on progress so far (assuming progress has a number). Could be used for anything I […]
encoded: I keep doing the same calculation over and over again, so I decided to make an online tool specially for it: >>> Linear time calculator <<< It’s a simple enough calculation to work out a time estimate for something based on progress so far (assuming progress has a number). Could be used for anything I suppose, but I keep doing this for long-running data processing scripts, where a count is being spat out to a log file e.g. a count of records processed. Here’s how the tool looks for script I was running recently. Alternatives Maybe I should’ve just worked out how to do the time format conversion and arithmetic properly in a spreadsheet, but why use a spreadsheet when you can build a whole dedicated tool for the job?! There are some similar existing online calculators. You can do the time between two date times on timeanddate.com which I suppose is the error prone part. Various online calculators do a speed calculation (division!) If you imagine “miles per hour” is “records per hour” it works.

Successfully spawning offspring
type: item
creator: Harry Wood
date: 2020-01-17T17:14:46Z
subject: kids
description: Our second baby arrived last week. Here she is. Our new baby girl! It was a planned C-section, and all went to plan, in contrast to the unexpected twists and turns of our boy’s birth which I blogged about four years ago. She seems partial to sleeping, sometimes for six/seven hours straight, and the breastfeeding is […]
encoded: Our second baby arrived last week. Here she is. Our new baby girl! <img loading="lazy" class="size-medium wp-image-748 aligncenter" src="http://harrywood.co.uk/blog/wp-content/uploads/2020/01/baby-holding-finger-298x300.jpg" alt="" width="298" height="300" srcset="https://harrywood.co.uk/blog/wp-content/uploads/2020/01/baby-holding-finger-298x300.jpg 298w, https://harrywood.co.uk/blog/wp-content/uploads/2020/01/baby-holding-finger-150x150.jpg 150w, https://harrywood.co.uk/blog/wp-content/uploads/2020/01/baby-holding-finger-768x774.jpg 768w, https://harrywood.co.uk/blog/wp-content/uploads/2020/01/baby-holding-finger.jpg 1000w" sizes="(max-width: 298px) 100vw, 298px" /> It was a planned C-section, and all went to plan, in contrast to the unexpected twists and turns of our boy’s birth which I blogged about four years ago. She seems partial to sleeping, sometimes for six/seven hours straight, and the breastfeeding is proving to be less stressful this time. Some of the same problems as last time, but this time we know what to look out for, and what we wanted to avoid! A second child is an important milestone in my life. My chosen mate and I have now successfully spawned offspring in sufficient numbers to replace ourselves and project forth our genetics to a new generation. I do feel like a successful organism now. <img loading="lazy" class="size-medium wp-image-749 aligncenter" src="http://harrywood.co.uk/blog/wp-content/uploads/2020/01/me-holding-baby-261x300.jpg" alt="" width="261" height="300" srcset="https://harrywood.co.uk/blog/wp-content/uploads/2020/01/me-holding-baby-261x300.jpg 261w, https://harrywood.co.uk/blog/wp-content/uploads/2020/01/me-holding-baby-768x882.jpg 768w, https://harrywood.co.uk/blog/wp-content/uploads/2020/01/me-holding-baby.jpg 871w" sizes="(max-width: 261px) 100vw, 261px" /> But we humans have long lifespans, and we rear our young for several years before they are ready to face the world on their own. I can confirm that even my older offsprin…

Open Data Camp
type: item
creator: Harry Wood
date: 2019-11-11T09:25:27Z
subject: Technology
description: I went to Open Data Camp 7 last weekend. It’s an event I’ve been hoping to get along to for years now. Always lots of interesting looking twitter chat coming out of it. But this year it happened in London, and I managed to be on the ball getting a (free) ticket before they sold […]
encoded: I went to Open Data Camp 7 last weekend. <img loading="lazy" class="alignnone size-medium wp-image-743" src="http://harrywood.co.uk/blog/wp-content/uploads/2019/11/open-data-camp7-logo-300x296.png" alt="" width="300" height="296" srcset="https://harrywood.co.uk/blog/wp-content/uploads/2019/11/open-data-camp7-logo-300x296.png 300w, https://harrywood.co.uk/blog/wp-content/uploads/2019/11/open-data-camp7-logo-768x759.png 768w, https://harrywood.co.uk/blog/wp-content/uploads/2019/11/open-data-camp7-logo.png 926w" sizes="(max-width: 300px) 100vw, 300px" /> It’s an event I’ve been hoping to get along to for years now. Always lots of interesting looking twitter chat coming out of it. But this year it happened in London, and I managed to be on the ball getting a (free) ticket before they sold out. I hadn’t particularly realised it’s the “unconference” format. It reminded me of the London “wherecamp” events I was involved in once upon time, although OpenDataCamp is even more unconferency. I mean the sessions were all very conversational. Didn’t see anyone with prepared slides, and often heard less from the session leader than from other people chiming in. <img loading="lazy" class="alignnone size-large wp-image-744" src="http://harrywood.co.uk/blog/wp-content/uploads/2019/11/odcamp_session-1024x768.jpg" alt="" width="640" height="480" srcset="https://harrywood.co.uk/blog/wp-content/uploads/2019/11/odcamp_session-1024x768.jpg 1024w, https://harrywood.co.uk/blog/wp-content/uploads/2019/11/odcamp_session-300x225.jpg 300w, https://harrywood.co.uk/blog/wp-content/uploads/2019/11/odcamp_session-768x576.jpg 768w, https://harrywood.co.uk/blog/wp-content/uploads/2019/11/odcamp_session.jpg 1200w" sizes="(max-width: 640px) 100vw, 640px" /> It was also different from wherecamp because there was a “pitching” session at the beginning to establish all the ideas. Those were then written up as a very busy schedule with four/five parallel tracks! Here’s all the sessions listed. In fact that h…