FeedCity

Includes cheesy little online explorer app.

Until a few months ago, for me streams were no more than an interesting and relatively straightforward concept in the context of messaging. After Kafka popularized the concept, I mostly investigated their usefulness in the case of Disque, a message queue that is now headed to...

Some brief notes on making ethernet cables With thanks to the most excellent NLNOG for a lot of mostly correct advice! Friends will tell you “crimping” ethernet cables is easy. Most of your friends either have overly rosy memories, or have practiced on 200 cables before telling you it is now easy. It is not easy. This page is for if you have a few extra euros/dollars/coins to spare, and don’t want to spend rare hours of concentrated effort to crimp an ethernet cable using unfamiliar equipment and supplies.

Building hardware is fun but tough. We worked on Pebble for a full four years before we launched on Kickstarter in 2012. We went on to sell…

I am pleased to announce that the Game Engine Black Book about Wolfenstein 3D has shipped. It is 316 pages, full color and made of three parts describing the hardware of the 1991, id Software tools, and the game engine internals. You can read a preview on Google Books and buy it here:

Amazon.com (.fr, .de, .co.uk, .ca,...).
Google Play Books for web browsers, Android devices, and iOS devices.

It took me three years to complete this project. It had its fair share of heavy winds and bumpy roads. I thought it could benefit some writers in the making to give a postmortem and share what I learned in the process.

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Today I read an interesting article about how the Wolfenstein 3D game implemented a fade effect using a Linear Feedback Shift Register. Every pixel of the screen is set red in a pseudo random way, till all the screen turns red (or other colors depending on the event happening...

I enjoy reading a lot of source code and after 15 years in the field I feel like I have seen my fair share. Even with a full-time job, I still try to spare evenings here and there to read. I don't see myself every stopping. It is always an oppo...

Onlangs vond ik via LinkedIn een advertentie voor de vacature ‘Senior Category Manager Domestic Appliances’ bij bol.com. Hierin stond zoveel wartaal dat ik het de moeite vond een ‘best of’ selectie te delen op Facebook. Daar vond men het ook erg grappig. Desondanks is het de moeite waard de vacature te decoderen: wat staat hier nou eigenlijk? Of exacter, wat bedoelen deze mensen. Komt ie. Update: Inhoudelijke reactie van bol.com in De Telegraaf

DNA: The Code of Life At the most magical SHA2017 gathering I gave two presentations, “DNA: The Code of Life” and the followup, “DNA: More greatest hits” (slides). The first presentation was recorded by the wonderful CCC C3VOC streaming crew, the second one by my friend Bart Smit (who is also wonderful). Without making this post too long, I want to thank everyone who helped me do this presentation — a lot of people contributed time, advice, recording abilities, great questions and enthusiasm.

How was Wolfenstein 3D made and what were the secrets of its speed? How did id Software manage to turn a machine designed to display static images for word processing and spreadsheet applications into the best gaming platform in the world, capable of running games at seventy frames per seconds? If you have ever asked yourself these questions, Game Engine Black Book is for you.

This is an engineering book. You will not find much prose in it (the author’s English is broken anyway.) Instead, this book has only bit of text and plenty of drawings attempting to describe in great detail the Wolfenstein 3D game engine and its hardware, the IBM PC with an Intel 386 CPU and a VGA graphic card.


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(Don’t) drop the hint: communicating with technical people This post is a subset of the presentation “Escaping the data center — tales from a recovering manager”. Video, slides. When we communicate at the office, we frequently do not directly say what we mean. A common conversation might go like this “Hey John, we did a survey and it turns out people can’t find what they are looking for on our website”.

On IP address encryption: security analysis with respect for privacy Frequently, privacy concerns and regulations get in the way of security analysis. I’m a big fan of privacy, but I’m also a big fan of security and preventing people from getting hacked. If you are hacked you have no privacy either. Per-customer/subscriber traces are extremely useful for researching the security of networks. Specifically, lists of DNS requests per IP address make spotting infected users or infected devices very easy, especially if you look at “yesterday’s traffic” and compare it to today’s threat intelligence.

On Linux vDSO and clock_gettime sometimes being slow Like the previous post on this somewhat dormant blog, I want to share an oddity I discovered that no search engine could really find for me - even though once I found what the problem was, it turns out I was by no means the first person to discover this. Some system calls that are used extremely frequently in Linux can be speeded up by a mechanism called vDSO: a virtual dynamically linked shared object.

Let's get some games written!

A 10x programmer is, in the mythology of programming, a programmer that can do ten times the work of another normal programmer, where for normal programmer we can imagine one good at doing its work, but without the magical abilities of the 10x programmer. Actually to better c...

After 10 million of units sold, and practically an endless set of different applications and auxiliary devices, like sensors and displays, I think it’s deserved to say that the Raspberry Pi is not just a success, it also became one of the preferred platforms for programmers t...

Remember how your parents would try to use Windows 95 or something like Norton Commander. They’d copy an app shortcut to a floppy disk and be amazed how much stuff they were able to put inside. All the games, and lots of space left! And you’d think they don’t understand anyt...

A theme of the last few books I’ve read has been user testing. Specifically, that it is completely unreasonable to suggest that you could produce a system that will work smoothly in production without first getting several actual human users unfamiliar with your system, from...

A few years ago, I've made a bunch of videos on YouTube about foundational topics in programming. There are lots of hand-drawn cartoons and some rudimentary animation. People keep asking how I made those, so here we go. Inspiration Structure and Interpretation of Computer ...