Interview with Eben Upton and Gordon Hollingworth

On what could be described as an average cold and drizzly British October day, I visited what is known to local people in Cambridge and to many people around the world as Raspberry Pi Towers. This made a welcome change to feeding the ducks or taking a ride on a punt on the river Cam. Taking in the towers of Kings College and the charm of Magdalene College is always a pleasure, and the colleges reverberate with new ideas and optimism.

Entrance to Raspberry Pi Towers can only be gained by being in touch with someone in the building. The electronic locks on the glass doors at the front are a necessary part of running a business in England. If you were walking along Castle Street, however, you wouldn't notice that you were looking at Raspberry Pi Towers. It looks just like any other glass and brick building.

After pressing the button on the intercom box outside, you will hear the reply of a secretary, who will ask you to state your business. Then, the glass doors will slide open and you are entering geek heaven. Shaking hands with Raspberry Pi inventor Eben Upton and others is a kind of unbounded joy that local Cambridge choirs sing about, but much better, because you can get out the soldering iron and oscilloscope and signal generator and play with them.

I met Eben Upton before he went to work for Broadcom. At the time, I remember him pondering whether an ARM chip might be used to build a small computer. My own point of view was that it might work but there might not be enough processing power in the ARM chips that existed at that time. Eben was on the design team for that ARM chip at Broadcom that has made its way into the Raspberry Pi, and Broadcom even supported the very first bit of design work for the Raspberry Pi board. Since then, Broadcom has been an enthusiastic backer of the project.

As any Raspberry Pi Geek reader will know, the present day ARM chip can do just about anything. Even some of the GNU/Linux developers who developed GNU/Linux on i386 chips have been heard to say that if ARM chips had been more powerful at that time then GNU/Linux might have become something else or might not even have been invented.

When I met with Eben Upton (@EbenUpton on Twitter), it was something of an honor and a pleasure, because Eben is a down-to-earth helpful chap who provides a fascinating account of himself and his experiences with building and marketing the Raspberry Pi [1]. Joining us was Gordon Hollingworth, also a Broadcom veteran, who worked on the original Raspberry Pi design. He is now the Director of Software Engineering at Raspberry Pi Towers. What follows is a shortened version of the interview [2].

Figure 1: Eben Upton

RPG: Did you have any interest in electronics or gadgets when you were younger?

Eben: Yeh … I had a BBC Micro when I was a kid. I had a ZX81 briefly which I got second-hand from a friend, but I couldn't make it work,

Gordon: Did your ZX81 have one of those RAM packs that fell off?

Eben: It did, but it didn't go so far as working well enough. So I was a Beeb guy and I bought my BBC Micro second-hand for £220. Model A and I upgraded to a model B RAM – 40/80 track double-sided disk drive.

RPG: Whoooaa! You had a disk drive?

Eben: I had a disk drive. This was 1988, so I had a really, really second-hand BBC. Had to hit it on the top to make it boot up. I did a lot of software stuff. Never really did much in the way of electronics when I was a kid. I only really got into that in my late twenties after I finished my PhD.

RPG: Gordon, you had a similar kind of experience?

Gordon: I had a BBC micro but slightly earlier than Eben, so I probably got into electronics much earlier. I think my Dad gave me a soldering iron and a TV. He said "take it apart." I ended up throwing it in the bin.

RPG: That's what happened to me when I was a boy! Here's a soldering iron. Get on with it.

Gordon: Absolutely. I remember once creating a voice digitizer for a BBC Micro. It was basically a comparator – a DAC and a comparator. That was at school in the mid '80s.

RPG: It's the way you learn I suppose? You have to start somewhere. Eben, what made you take a degree in physics and engineering at the University of Cambridge?

Eben: So, I came up to read physics. I guess I enjoyed physics at school. I had this weird idea that I really enjoyed computer programming, but I didn't want to do it for a degree. I did 25 percent programming for the first year. Then I dropped that and went and did physics and then dropped that and did engineering. It was called the Electrical Information Sciences Tripos or EIST. Then, I did a diploma in computing sciences which was based on something left over from the 1950s. It was a repackaging of a some of the undergraduate courses into something like a conversion post-graduate course. Lot of cool people have done that course.

RPG: Gordon, did you do your degree at Cambridge?

Gordon: No. I was at York actually. I did electronics at York. I didn't go there directly. I did an apprenticeship with the Ministry of Defence for four years before that and then went off to York. I did a PhD after that. York was a great place to go to. I was there for a long time.

RPG: Eben. Broadcom. What was the reason you went to work for them?

Eben: I had a friend who was a year ahead of me on the course, who was called Neil Johnson. He kept telling me how much fun Broadcom was. What I didn't know was that there was a referral bonus in place for him to get me interested in Broadcom. I went along to the interview for Broadcom. I was nearly 15 minutes late. I was out working with this guy I know who does low-voltage regulators for wheelchairs. I was covered in bits of solder flux all over my clothes. I looked at my watch it was 15 minutes to ten. I drove like blazes to get to the interview 15 miles away. Got there about one minute to ten – totally not paying attention. I went into the interview to shut my friend up and came out desperate for them to call me.

RPG: Do you think that working at Broadcom did a lot for you?

Eben: Absolutely. It's a great place. It's an amazing company.

Gordon: When I arrived at Broadcom the amazing thing I always found was the density of really clever people and the scarcity of mediocre people.

RPG: Seen some of the things in Silicon Valley in California myself. I went out there to study. You meet people who can just do things. Things that might not be possible in the United Kingdom or elsewhere.

Eben: Gordon arrived at Broadcom about a month before me. We were kind of the new boys.

RPG: The Raspberry Pi uses a Broadcom chip?

Eben: As you say. The Pi uses a Broadcom chip. Gordon and I were on the design team for that chip at Broadcom – separately. Broadcom did support the very first bit of design work for the Pi and remain an enthusiastic backer of the project in general.

RPG: You have been a visiting researcher at Intel?

Eben: I did some work on something called Haggle [3], which is an ad hoc networking technology. Used Bluetooth intermittent devices to transport best effort datagrams – slow transport datagrams. I wrote a thing called BlueCove, which is still in use. It was an implementation of JSR, which is the mapping of Bluetooth into Java – which is part of the J20E standard I wrote. I was rather pleased to see the other day that someone had posted a question about this on the Raspberry Pi forums. Somebody trying to get BlueCove going on the Pi. When you think about it, the whole thing has been continually built and developed since 2004; there is an enormous list of contributors associated with my name. <smiles>

RPG: Well, at least this is something that you can do with open source software. As long as you don't get run over by patent trolls, then things tend to just go along nicely. Hopefully.

Eben: The Intel lab in Cambridge [was] a short-term thing, but it was a good experiment, and it was good fun.

RPG: The Raspberry Pi Foundation [4]. Can you tell me anything about that?

Eben: It's what it looks like. It's a charity. Its mission is not to build a large number of computers. It exists to get more children interested in computers, which is what we need.

RPG: A superb educational tool.

Eben: The foundation's mission is to get more children computing by any means necessary. We've been running since 2009 – based in Cambridge. We've done some fun stuff.

RPG: What about the future of Raspberry Pi? Where do you see it going to? At the moment it's a raging success.

Eben: It's going to become more of a success! Was that a trick question? It's going to decline?

RPG: Just wondered if you had any visions for the future.

Eben: We want to make the software better. I think that goes without saying. The nice thing that we've discovered is that we've got this platform that's really worth our spending the money on it. It's a software story at least for the next couple of years.

Gordon: Trying to turn it into almost something like a building block system, so that people can take our libraries. We are trying to create libraries and improve them, so that people can have a look and put some ideas together. They can see that they can use a library or a series of libraries and create an application. That's something that we are trying to push forward.

RPG: Take a brilliant idea, make it better.

Eben: Try to find out what the users want and invest money in it. A good example of this is Smalltalk [5]. It's a minority interest language, but there's a vast amount of information in it for educational use … a lot of people use [it] for teaching young kids. So, we've been spending a surprisingly large amount of time and money on making Smalltalk run well on Pi. There's probably four or five of those things that we need to improve, such as making the web browser run quickly. There are others which the community are working on.

Eben ended our meeting by giving the customary demonstration of the Raspberry Pi. He showed the five-megapixel camera that works with the Pi. Many projects out there are great to work on and do not require much effort to produce a working gadget. The Raspberry Pi offers a great way to learn or teach about electronics or software.

The day before this interview took place HRH Prince Andrew visited Raspberry Pi Towers (Figure 2) [6]. Prince Andrew is well informed about the background of the Raspberry Pi Foundation and the changing educational curriculum in the UK. He knows about the growth of groups like Code Club [7], Young Rewired State [8], Teen Tech [9], and others, as well as the need for new young programmers.

Figure 2: HRH Prince Andrew visits the Raspberry Pi Towers.

As this article went to press, an announcement was made that two million Raspberry Pis had been sold [10]. This confirms that it's a raging success, just like the BBC Micro and the Sinclair ZX series of computers [11] before it. These developments, along with the Commodore 64 [12], brought about the personal revolution in home computing, which, along with the introduction of the World Wide Web, changed our lives forever.