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.

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 »

22 June, 2015

I have another article published over at This time I am looking at an interesting adaptation of technology, where investment in one context is yielding benefits in another. It can be a significant overhead adding a user interface to a deeply embedded system, but there is an interesting option which is worth investigating … Read the rest of this entry »

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18 June, 2015

I am not a superstitious person. As I have a strong interest and faith in science, I believe that there is a rational explanation for everything. In some cases, we might not have mastered the necessary science, but we will get there. After all, to anyone from, say, the 19th Century, much of our everyday technology today would appear to be magic. I do like an interesting coincidence, but these can commonly be explained by the 6 degrees of separation.

However, occasionally odd things do happen … Read the rest of this entry »

15 June, 2015

Computers have had operating systems almost since the beginning – 60 years or so anyway. Embedded systems are a bit newer, of course, and it was the early 1980s when the first OS products appeared. Naturally, they were real time operating systems [RTOSes], as this matched the needs of the systems being built, as it often does today. The first commercially available RTOS was [probably] VRTX [pronounced “vertex”], which was developed by a company called Hunter & Ready, which became Ready Systems. They were acquired by Microtec Research, where I was working at the time. We got acquired by Mentor Graphics, where I still am today. VRTX was mothballed a few years ago and we moved on to selling the Nucleus RTOS after the acquisition of Accelerated Technology.

The RTOS market has always been interesting, with lots of options. There are around 200 products on the market, but still there are more companies trying to get in on the act … Read the rest of this entry »

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11 June, 2015

I recently mentioned that I was planning – or at least seriously considering – moving from Windows to Mac as my primary computing platform. I immediately received some very positive responses from guys who have already made the move and were keen to share their enthusiasm. I thought that this might be a good time for an interim report on my progress.

When my wife asked me what I thought of the MacBook Pro after I had been using it for a while, I used a word which she did not believe she had ever heard me utter before. Suffice it to say, in summary, I will quote a well-known vendor of fine food: “I’m lovin’ it” … Read the rest of this entry »

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4 June, 2015

All through my career I have traveled quite lot for my work and find it hard to imagine any other kind of life. It can be hard to explain to people, who have not experienced business travel, that it is not one long vacation, particularly because, at times, it can be fun. It is also tiring. I cannot fully explain why just moving around the planet leaves me so weary. Certainly the hassles at airports etc. take their toll, but I think that just adapting to change is more taxing than one might expect.

Our high tech world helps us cope with change in some ways – keeping in touch with home has never been easier – but it also introduces new challenges … Read the rest of this entry »


1 June, 2015

It is common for C to provide several different ways to do something, all of which are exactly equivalent. For example, given that x is a normal int variable:

x = x + 1;

is exactly equivalent to:

x += 1;



The only possible difference is that a less capable compiler might generate slightly better code for the second and third options [which would be a hint that getting a better compiler would be worthwhile].

However, sometimes constructs that appear to be equivalent have very subtle differences … Read the rest of this entry »

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28 May, 2015

I have been using PCs for about 30 years. Initially, they ran MS-DOS. Windows was an option for some years, but was not compelling. Then Windows 3.1 was released and, all of a sudden, so it seemed, that was the way forward. I never looked back. I have used Windows ever since – both through personal choice and my employers’ requirement – through numerous versions: 95, 98, [avoided ME], 2000, NT, XP, [avoided Vista] and 7; have never tried 8/8.1

That was then; this is now. Sometimes in life, enough is enough … Read the rest of this entry »


25 May, 2015

It is hard to believe that it is almost 20 years since Mentor Graphics started to build a presence in the embedded software world by acquiring Microtec Research [and getting me as a result]. There has been much development and numerous other acquisitions [most notably Accelerated Technology] since then and the Embedded Systems Division [a.k.a. Mentor Embedded] has gone from strength to strength.

However, the worlds of embedded software and electronic design automation [EDA] have remained surprisingly separate … Read the rest of this entry »

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21 May, 2015

For me, it is always a pleasure when a number of my interests become aligned – sometimes the resulting whole is greater than the sum of the parts. This happened with digital photography, for example. For years I had used film and I had worked with and enjoyed computers; now they have come together nicely. Just recently, I heard about something that promised to yield the same kind of benefit … Read the rest of this entry »


Meet Colin Walls

I have over twenty-five years experience in the electronics industry, largely dedicated to embedded software. When not working, I enjoy photography, books and music. Learn more about me, including my go-to karaoke song and the best parts of being British.

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  • ECS Syd
    March 10-11: Dynamic Memory Allocation & Fragmentation in C & C++; Self-testing in Embedded Systems; Power Management in Embedded Systems