Thank You, Sir Clive Sinclair

A few days ago, Sir Clive Sinclair died. I owe him, or rather his most successful product, my career as a computer scientist. I bought myself a ZX Spectrum in my early teens, taught myself how to program it, and never looked back. The ArsTechnica obituary calls the Spectrum a “gaming computer”, and I guess that is mostly fair. Can’t say I ever used it for more than playing games or programming games.

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Timesharing System Design Concepts (1970)

When I recently turned 50, a friend of mine gave me a book that was about as old as me – Timesharing System Design Concepts, by Richard W Watson. The copyright date is 1970, but the publishing date found online 1971. The book covers the hardware support and software techniques needed to provide multiple users with simultaneous access to a computer system. Typically, using remote teletype terminals. It is a wonderful book, reflecting on the state of computer technology around 1970. It shows both how many of the basic concepts we still use today were already in use back then, but at the same time just how far we have evolved computing since.

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Cancer Part 4: All’s Well that Ends Well

I last blogged about my experience with thyroid cancer in early 2020. Back then, I said that I felt pretty much normal. That has indeed continued to be the case, and recently I was declared as having formally recovered from the cancer. The guideline is apparently that after two years with no sign of a cancer resurgence, you are considered fully recovered. Future follow-ups are the responsibility of the primary care system instead of the hospital, with something like yearly or bi-yearly follow-up tests. Not so much to look out for the cancer, but to keep the Levaxin prescription correct.

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The SAMOS XXI Conference (Virtual)

The International Conference on Embedded Computer Systems: Architectures, Modeling and Simulation (SAMOS) XXI conference took place a couple of weeks ago. Like all other events in the past 18 months, it was virtual due to Covid-19. For more on the background on the SAMOS conference, see my blog post about SAMOS XIX (from 2019). This year, I presented a tutorial about our public release of the Simics simulator and took the chance to listen to most of the other conference talks.

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Oljeön – The World’s Oldest Preserved Oil Refinery

With Covid-19 still a bit of an issue, the summer of 2021 is yet another one for “svemester” (Sverige-semester, or Sweden-vacation). There are plenty of things to see, and one place that I finally got to visit was the old oil refinery at Oljeön in Ängelsberg, home to Engelsbergs oljefabrik and the world’s oldest preserved oil refinery dating back to the mid-1870s. It is a beautiful piece of industrial history, well-preserved and with good guided tours.

View of Oljeön from the mainland. The refinery is the yellow building on the right, the darker building on the left is the one remaining oil storage shed
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Microsoft Windows memset Optimization – Stores are Free

I recently stumbled on a blog post called Building Faster AMD64 Memset Routines, written by Joe Bialek of the Microsoft Security Response Center (MSRC). The blog describes his efforts to improve the performance of the Windows kernel memset() function, across all sizes of memory to set. The reported optimizations are quite fascinating, and could be summed by avoiding branches even at the cost of doing redundant stores. Basically, stores are free while branches are expensive.

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About Virtual Events

Just like most people who can, I have been working from home since March 2020 due to Covid-19. Now that we are hopefully seeing the end of the pandemic in the west, it is worth looking back at the conference-from-home aspect of work-from-home. I have seen our Simics training, the Design Automation Conference (DAC), the Design and Verification Conference (DVCon) Europe, commercial training events, talks at industry conferences, guest lectures, and multiple internal Intel events go virtual.  It has been interesting to see how this has worked out, and it seems to me that we are starting to see some good recurring patterns. People have adapted and figured out how to use video meeting technology better and better.

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Jerry Fiddler on the Early Days of Wind River and Building a Product

Wind River is celebrating their 40th anniversary as a company with a series of historical look-backs posted on the Wind River channel on YouTube. One of the videos is an interview with Jerry Fiddler who founded Wind River back in 1981, by Wind River current CEO Kevin Dallas. Jerry Fiddler talks about how he got started in computers, and especially about how Wind River got started and grew.  It is both a fantastic set of historical anecdotes and some solid product management and strategy insights.

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DRAMsys – Cycle-Accurate Simulation using Transactions

DRAMsys is a simulator for modern RAM systems, built by researchers at Fraunhofer IESE and the Technische Universität Kaiserslautern. Over the past few years, I have heard several talks about the tool and also had the luck to talk a bit to the team behind it.  It is an interesting piece of simulation technology, in particular for how it manages to build a truly cycle-accurate model on top of the approximately-timed (AT) style defined SystemC TLM-2.0.

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Professor Reinhard Wilhelm on the History of WCET Analysis

Back when I was a PhD student working on worst-case execution-time (WCET) analysis, one of the leading groups researching the topic was the “Saarbrücken gang” led by Professor Reinhard Wilhelm. Last year, Professor Wilhelm published a retrospective look on their work on WCET in the Communications of the ACM. It is a really interesting history write-up from the perspective of the Saarbrücken group.

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Renovations and Software

Last year, we spent a significant part of the fall and early winter renovating some aspects of our apartment*. Things like (finally) updating the flooring in the living room, updating the wallpapers, painting the interior staircase white, and changing out all doors. The renovation process provides some interesting analogies to the process or updating an existing software code base – especially in discovering the design decisions of the past and unearthing the layers of legacy that underlies why things look like they do today.

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Corsair K83 – Living-Room Keyboard

I have had a PC in the living room connected to the family TV for a few years now, and in the past we used a wired Corsair K65 keyboard with it. The point of the machine was at least in part to play games, and for that a mechanical wired keyboard is de-rigeur (and I do love RGB backlighting). However, some recent changes to the computer fleet made the living-room PC into more of a media machine, and it was time to move to a wireless keyboard. Preferably one that also made the mouse superfluous. After some research, I ended up with the Corsair K83. I am rather happy with the keyboard overall, even though it is rather small and lacks RGB.

The Corsair K83 on a holiday-themed tablecloth
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The First Swedish Programmer (1790s)?

The history show (and podcast) of Sverige Radio, Vetenskapsradion Historia, is one of the shows that I subscribe to and listen to regularly. In their look back at 2020, they reminded me of an episode from back in the summer that indirectly introduces what I believe to be the first programmer in Sweden.  

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DVCon Europe 2020 – Developing Hardware like Software?

The Design and Verification Conference Europe (DVCon Europe) took place back in late October 2020. In a normal year, we would add “in München, Germany” to the end of that sentence. But that is not how things were done in 2020. Instead, it was a virtual conference with world-wide attendance. Here are my notes on what I found the most interesting from the conference (for various reasons, this text did come out with a bit of delay).

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USB-C Works, but how would you Know?

Using USB-C to charge a laptop while simultaneously providing display and other IO traffic sounds a little bit too good to be true in practice.  Maybe it would work for a set of devices from a single manufacturer (like a Thunderbolt-based USB-C-attached dock from the same vendor as a laptop). However, recently I was surprised (in a good way) when it turned out that I had accidentally got myself a USB-C-based single-cable-to-the-laptop setup. USB-C promises a lot, in this case it delivers perfectly, but what bothers me is the fact that there is really no way I could have figured this out ahead of time.

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CACM on DSAs

The July 2020 edition of the Communications of the ACM (CACM) had a front-page theme of “Domains-Specific Hardware Accelerators”, or DSAs. It contained two articles about the subject, one about an academic genomics accelerator, and one about the Google TPU. Hardware accelerators dedicated to particular types of computation are basically everywhere today, and an accepted part of the evolution of computers. The CACM articles have some good tidbits and points about how accelerators are designed and used today. At the same time, I also found a youtube talk about the first hardware accelerator, the IBM Stretch HARVEST, showing both contrasts with today as well as a remarkable continuity in concept.

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Intel Blog: How Teaching Users Drives Product Improvements in Simics

I have a post out on the Intel Software blog about my experience developing and delivering training for Simics over the past few years. A key observation is that building training is a great way to test the product, and drives changes and improvements in the product. The blog is found at https://software.intel.com/content/www/us/en/develop/articles/teaching-users-drives-product-improvements-in-simics-sw.html

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Going Norrland

This year’s vacation trip was a roadtrip into Norrland, the northern part of Sweden. With the ongoing Covid-19 pandemic, it seemed safer and fairer to the healthcare system to stay in our own country.  It was also an opportunity, since I have wanted to and look at some places up north for quite a while now (such as Bodens Fästning and Hemsö Fästning).

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Hemsö Fästning – Coastal Defense from the 1950s

Continuing on my blog posts about our Hemester (part 1 covered Bodens Fästning), this blog post will cover Hemsö Fästning. Both are fascinating places, but also rather different, and clearly demonstrate the changes from the early 1900s to the Cold War of the 1950s.

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Bodens Fästning – A Fortress in the North of Sweden

Due to Covid-19, this year’s summer vacation involved a “staycation”, or “hemester” as we say in Swedish. We went up north in Sweden, and took the chance to visit some military museums. In particular, the fortresses at Hemsön and Boden (fästning means fortress). Both are fascinating places, but also rather different, and clearly demonstrate the developments from the early 1900s to the Cold War of the 1950s. This post covers Boden, with a separate post for Hemsö released a few days after this post.

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The Virtual DAC 2020

I have attended the Design Automation Conference (DAC) occasionally for the past decade – maybe every second or third year. The DAC is typically mostly about the lower levels and the backend of hardware design, but there is always something to learn about virtual platforms and related topics closer to my interests. This year, like last year, I got a presentation (and poster) accepted for the Designer track. The DAC organizers held out hope for a physical conference for quite a while (back in early March it seemed rather unlikely that this would still be with us in July…). However, a physical conference was not to be, and the DAC switched to a virtual format in early May.

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Recalling the Beginning of Covid-19 and Work-from-Home

Recently, we had a discussion at work (in our daily virtual team “fika”) where we reflected on just how many weeks we had been working from home due to the Covid-19 pandemic. It has been quite a few; I last saw the office in week 11, and week 19 is beginning… so I am looking at eight weeks personally. Just how did it all begin? I thought it useful to go back and try to remember how we got to this point. In hindsight, I never thought it would be this huge.

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Adjusting to Work-from-Home: Remote Live Simics Training

In the current world-wide lockdown due to Covid-19, many things that were done in-person in the past have to become virtual. The Simics® New User Training that we run at Intel and with our customers and partners is no different. In normal times, we run in-person classes around the world, but that is not an option right now.  Thus, we shifted to running remote live classes as a substitute for the time being. This blog shares some of my experience from running remote live classes.

We changed the cover page of the Simics training to symbolize the change.
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Cancer Part 3: So Far So Good

It has been a bit more than six months after my radiotherapy treatment for thyroid cancer, and I feel pretty much normal. Several times over the past few months, I have talked to people I have not seen in a while and they have asked me how I am doing. At first I just say “fine”… and I then realize that they are asking about the cancer. It’s not top-of-mind for me since I have been living with it for almost a year now, and it feels (currently) like it is “done”. Of course, it will be years before I am formally considered to have fully recovered, but right now I feel like I am functioning mostly normally (except a small side-effect from the medication).

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Intel Blog Post: “Quit Thinking and Look” – Mea Culpa Chasing a Performance Bug

I have written before about the debug advice to “Quit thinking and look.” It means that you should not form conclusions prematurely. Stop and look at what is going on instead of guessing and cooking up theoretical scenarios. Sound advice that I completely failed to follow in the case that I just chronicled on my Intel Blog: https://software.intel.com/en-us/blogs/2020/03/18/quit-thinking-and-look-chasing-simics-performance

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Intel Blog Post: Shift-Left for a Snowy Ridge

There is a new blog post on the Intel Developer Zone on how we used Simics virtual platforms for the new Intel® Atom® P5900 series of system-on-chip (previously known as Snow Ridge). It talks about how shift-left works both inside of Intel and with our customers for the new chip, and the kinds of virtual platform models you use for different types of use cases.

See https://software.intel.com/en-us/blogs/2020/03/17/seeing-the-early-snow-on-the-ridge

Simulating Computer Architecture with “Mechanistic” Models – No more 100k Slowdown?

I have been working with computer simulation and computer architecture for more than 20 years, and one thing that has been remarkably stable over time is the simulation slowdown inherent in “cycle accurate” computer simulation. Regardless of who I talked to or what they were modeling, the simulators ran at around 100 thousand times slower than the machine being modeled. It even holds true going back to the 1960s! However, there is a variant of simulation that aims to make useful performance predictions while running around 10x faster (or more) – mechanistic models (in particular, the Sniper simulator).

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Additional Notes on Spotify

After about a month of using Spotify, it is time for an update. I got several people asking about how I was doing with Spotify, based on my previous blog post about the service. The results so far have honestly surprised me – it has become my default way of listening to music, despite all of my previous criticisms being pretty much validated. I guess the “access any song” is really a compelling value proposition, strong enough to overcome the limited organizational tools.

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The Benefit of Live Teachers (Applied to Myself)

I have been spending quite a bit of time in recent years developing training materials and doing trainings for Simics. There is always a discussion on how best to do training, in particular between live sessions with actual trainers and offline video and other self-study resources. I am a firm believer in the value of live training, and during our recent winter vacation up in the Swedish mountains I made myself provide a perfect example of the value of a teacher. I took a skiing lesson.

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I Finally Gave up and Tried Spotify

I am probably among the last people to have tried Spotify. When the service first arrived ten years ago I looked at it and concluded it seemed a poor match for my needs. To me, music is something you buy and own permanently in the style of old-fashioned CDs. The whole idea of a streaming service where an artist, album, or song could go missing all of sudden due to factors beyond your control just seemed (and still seems) suspicious. Everybody else seemed to love it, but that does not necessarily mean it is good…  However, I finally did jump in and try Spotify, and here is what I found.

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