The Colin Walls Blog

This blog is a discussion of embedded software matters - news, comment, technical issues and ideas, along with other passing thoughts about anything that happens to be on my mind.

1 October, 2015

There is an old saying: “A change is as good as a rest.” Although I am sure that it has often been used to avoid giving someone a well-earned rest, it does have some intrinsic truth, in my experience. On more than one occasion, I have been on a very active vacation, with lots of walking etc., where I ended every day physically tired. Yet I came home feeling refreshed and renewed.

Having said all this, most of us are rather resistant to [voluntary] change … Read the rest of this entry »

28 September, 2015

In a similar way to blog posts here, I often endeavor to address a specific technical matter, that is pertinent to embedded software, in articles I publish elsewhere. Sometimes the topic is a matter where a developer does not need a detailed knowledge on a day-to-day basis, but an understanding of what is going on “under the hood” may be useful. My latest article on is a good example … Read the rest of this entry »

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24 September, 2015

80606CD5-FFAF-430A-A7B4-3D0C036B5F2ESome weeks ago, I wrote about my planned transition to Mac. Well, that is now history. My iMac, with its beautiful 5K display, is my new Best Friend. I successfully transitioned all the software/activities from Windows to Mac in one of three ways:

  • I simply installed the Mac equivalent of the Windows software. Examples are MS Office, which works beautifully, and Adobe Lightroom, which required care to transfer [I could do it more easily knowing what I know now], but is now in its element.
  • I found other apps to replace some things I needed.
  • I looked for other approaches to achieve my goals. These rethinks mainly seemed to result in a better solution than I had before.

The process has not been without pain, but it was worth it. Apple computers are not perfect, but my day to day hassles are now reduced drastically. I am not going back!

Yesterday, I had reminder of the car crash that is Windows on a bad day … Read the rest of this entry »

21 September, 2015

Embedded systems, much as we know them now, have been around since the early 1970s, when Intel released the first really practical microprocessor. In those days, the term “embedded systems” had not been coined – that did not come along for another 20 years. I wrote a book, which was published in 1986. There was a long list of possible titles, but the word “embedded” did not appear. It was finally called “Programming Dedicated Microprocessors”.

I have always had trouble explaining what I do professionally. People understand that I work with software, but are confused when I cannot necessarily help them make their PC work better. I have to explain what an embedded system is. The description I use is something like this: Inside almost all modern electronic devices are tiny computer chips called microprocessors. They run a fixed program to provide the required functionality to the device. That is an embedded system … Read the rest of this entry »

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17 September, 2015

They say that a vacation is beneficial because “a change is as good as a rest”. I think that there is something in that, as I can go away somewhere and do lots of stuff, but still feel rested and refreshed. Having said that, I believe that there are benefits to be had from doing not very much. Go to any of the warm Mediterranean countries – and I have just spent a few days in that kind of area – and you notice that the people lead their lives at a slower pace. I have noticed, in recent years, that when two people meet, their dialog might start off with something like: “How’s it going?”, “Good. Very busy.”

I am not sure that this is necessarily good or healthy … Read the rest of this entry »

10 September, 2015

When I was a kid, I tasted some beer and found out that I did not like it. It was too bitter – I much preferred sweet things. In an ideal world perhaps, I would have left it like that – simply labelling beer in my brain as something I did not like. However, I wanted to like it as it seemed to me to be a very grown-up kind of drink for a man to imbibe. I persevered and eventually grew to enjoy almost any kind of brown liquid in a glass. I do not reject other possibilities. I am OK with cider; I very much enjoy wine; I do not really bother with strong liquor. Beer has always been there, in numerous forms and continues to interest as well as refresh me.

The whole culture of beer makes choosing the “best” six challenging, but I will give it my best shot … Read the rest of this entry »

4 September, 2015

When I was a kid at school, I thought that history was a waste of time. What was the point of learning about stuff that has been done and cannot be changed? I could see the sense in understanding recent stuff, but all those kings and queens and battles …

As I have grown older, I have gradually understood how we can learn from history and avoid making the same mistakes. Often we simply repeat those mistakes anyway, but that is just human nature. Just recently I have been pondering how some recent history could have turned out very differently … Read the rest of this entry »

20 August, 2015

I have always been fascinated by the measurement of things and our perception of those measurements. I constantly bump into conflicts and synergies between systems. For example, I have been known to refer to the size of something as being “between one centimetre and half an inch”. On the other hand, the inherent illogicality [to me] of the Fahrenheit temperature scale befuddles me.

I recently wrote about a specific kind of measurement – that of drinks. I have now found some more information … Read the rest of this entry »

17 August, 2015

Some weeks ago, I mentioned that I was planning a series of video blogs. This met with some enthusiasm from potential viewers, which has encouraged me to proceed with the project. the videos will not replace this written blog, but supplement it.

The first video, where I discuss the plans for the coming weeks, is online now:

Here are some topics which we be covered in the next few postings:

  • Would you buy a TCP/IP stack from me?
  • Assembly language is always smallest/fastest – not!
  • Language extensions
  • Y2K redux
  • USB: easy, but …

I welcome all feedback, particularly suggestions for future topics, by email, comment or via social media.


13 August, 2015

For most of us, most of the time, having enough light to see, read or do whatever is not a problem. If there is no available daylight, because of the time of day or our location, we just press a switch. Let there be light! But, of course, it was not always that easy. The invention of fire was, I suppose, the first artificial light – though that was not its main attraction/function.

For the most part, light was simply available from the sun … Read the rest of this entry »

10 August, 2015

It seems that hardly a day goes by during which someone does not say “This is like science fiction!” Typically, they are talking about cell phones, GPS, tablets, cars with keyless ignition – the list goes on. Only this morning, I was using Apple Pay [which has just been launched in the UK] to get my breakfast and the server smiled and said “Love technology …”.

These are all embedded systems [or the close relatives thereof] and are very complex … Read the rest of this entry »

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6 August, 2015

I think that I should explain straight away – if only for the benefit of my wife, who may be reading this – that I am using the word “failed” in a slightly unconventional way. Actually, the same is true for “advice”, as you will see.

When I was much younger, before I went to university, I used to speculate on whom I might marry. I occasionally suggested that the ideal girl would be the daughter of a successful brewery owner. I suppose she would have needed to have some other attributes as well, but that was never clearly defined. As it turned out, I have married two women, neither of whom [to the best of my knowledge] have any connection with the brewing industry … Read the rest of this entry »

3 August, 2015

It is a very simplistic view, but, broadly speaking, there are two ways to design an embedded software application [or pretty much anything really]: either top-down or bottom-up. There are pros and cons of each approach and it is hard to say, in the general sense, that one is better than the other.

So much for design, but how development is approached is another matter … Read the rest of this entry »


30 July, 2015

There are two topics that I carefully avoid discussing in this blog: religion and politics. I would only have to touch on either of these and I would alienate a whole bunch of people. I have plenty of other ways to generate alienation, so it seems only reasonable to avoid the obvious. In “real life”, I am also wary of these topics, but, with the benefits of the richer communication afforded by an in-person dialog, upset can be minimized or avoided.

Today, however, I am going to almost disobey by rule. And I am not going to talk about religion … Read the rest of this entry »

27 July, 2015

I have a very strong resistance to the practice of doing something [anything!] just because “it is the way we have always done it”. I love to play Devil’s Advocate [or “Devil’s Avocado” as I heard someone quip the other day] and propose change just to shake things up. It may be that the tried and tested approach is, indeed, the best, but you cannot be sure until you have considered that other options.

When it comes to embedded programming, it is easy – most people use C or similar languages. But is that the only way? … Read the rest of this entry »

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23 July, 2015

Categorizing people is something that we all do. It can be judgemental, which is bad. However, a degree of analysis of an individual’s personality type may be useful. I, for example, am an introvert. That does not mean that I am totally uncomfortable with large crowds of people. It simply suggests that I gain my energy from having time alone. An extrovert is the reverse – gaining energy from being with people. I have found this categorization, and my understanding of it, helpful and normally ensure hat I have some “me time” when I have been engaged in social activities.

I am also shy, which is something different and not really that well understood … Read the rest of this entry »

20 July, 2015

I am involved in an interesting project, with which I need some help. And that might be where you come in. I had an idea for a book and managed to persuade the inimitable Clive (“Max”) Maxfield to work with me on it. The plan is that he and I will write some sections and jointly edit the whole book. We have an agreement with Elsevier to publish the fruit of our labors, so we are now somewhat committed.

This is why I am now asking for help … Read the rest of this entry »

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16 July, 2015

In the UK, there is a very popular radio show called Desert Island Discs. This show has run continuously for more than 70 years – it was first broadcast in January 1942. I believe it might even hold the world record for the longest running radio program. The format of the show is quite simple. Each week, a famous person is invited as a guest. They are asked to imagine that they are the sole surviver of a shipwreck and have the opportunity to rescue a few artifacts before it is all washed away. Specifically, they can choose 8 records [tracks nowadays – usually music but can be spoken word], a luxury item [which must not be useful for survival] and a book [the Bible and complete works of Shakespeare are provided as a bonus]. The show takes the form of an interview, where the guest talks about their life, with the 8 tracks interspersed. It is always fascinating listening and I believe that many people regard an invitation to participate as being equivalent to getting an honor from the Queen.

A member of my family came up with the idea that we should all play the game and submit our Desert Island Disc selections. I though that I would share my contribution here … Read the rest of this entry »

13 July, 2015

For me, the Embedded Systems Conference has been an important date on my calendar for many years. The conference has been given various different names over the years, but I am glad that its identity has finally been restored. The event has moved around the year somewhat and similar events have been organized at other locations around the world.

The Silicon Valley ESC, which takes place next week, is somehow the “real thing” … Read the rest of this entry »

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9 July, 2015

I am always interested in the way businesses are run, often being amazed at how haphazard and unplanned many seem to be. When I buy a product or use a service, I will often provide feedback – a well managed business thrives on customer input, good or bad. I am always impressed when I come across a well run business – I even have a talk, which I have delivered in a couple of schools, for example, which looks at a number of interesting examples of companies and individuals who are just “doing it right”. It is also interesting, but rarely pleasurable, when businesses get it wrong.

I just returned from a short vacation [they never are long enough!], which gave me the opportunity to study a business and figure out its good and bad points … Read the rest of this entry »

6 July, 2015

A topic that I find particularly interesting, which is raised by many embedded software developers whom I meet, is dynamic memory allocation – grabbing chunks of memory as and when you need them. This seemingly simple and routine operation opens up a huge number of problems. These are not confined to embedded development – many desktop applications exhibit memory leaks that impact performance and can make system reboots common.

However, I am concerned about the embedded development context … Read the rest of this entry »

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2 July, 2015

I enjoy cooking and like to try new things from time to time, as well as preparing old favorites. Normally I look for a recipe and the obvious place that I start is the Internet. The result is that many recipes that I find are American, which can mean that ingredients are unavailable or have odd names, but I can generally get around that. It also means the measurements are unfamiliar. Temperature is in Farenheit, weights are in ounces and liquids might come in fluid ounces. However, they might come in cups … Read the rest of this entry »

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