IBM i – I’m Impressed

From what little I had heard and read, the IBM AS/400 (later known as iSeries, and now known as simply IBM i) sounded like a fascinating system. I knew that it had a rich OS stack that contained most of the services a program needs, and a JVM-style byte code format for applications that let it change from custom processors to Power Architecture without impacting users at all.  It was supposedly business-critical and IBM-quality rock solid. But that was about it.

So when Software Engineering Radio episode 177 interviewed the i chief architect Steve Will, I was hooked. It turned out that IBM i was cooler than I imagined. Here are my notes on why I think that IBM i is one of the most interesting systems out there in real use.

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Steve Furber: Emulated BBC Micro on Archimedes on PC

I just read an interview with Steve Furber, the original ARM designer, in the May 2011 issue of the Communications of the ACM. It is a good read about the early days of the home computing revolution in the UK. He not only designed the ARM processor, but also the BBC Micro and some other early machines.

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Cubase64 – Impressive Impossible Retro

I recently read the “Cubase64 White Paper” by Pex Tufvesson. It is a fantastic piece of retro computing, where he makes a Commodore 64 do real-time audio effects on a sampled piece of music. There is a Youtube movie showing the demo in action. Considering how hard we worked in the early 1980s to make a computer make any kind of useful noise at all, this is an amazing feat. It is also a feat that I think would have been impossible at the time.

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Simple Machine, Hard to Simulate

In the June 2010 issue of Communications of the ACM, as well as the April 2010 edition of the ACM Queue magazine, George Phillips discusses the development of a simulator for the graphics system of the 1977 Tandy-RadioShack TRS-80 home computer.  It is a very interesting read for all interested in simulation, as well as a good example of just why this kind of old hardware is much harder to simulate than more recent machines.

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EDSAC – First Bootloader and Assembler

The EDSAC was an early computer in the mathematics laboratory at Cambridge in the UK. I have just read an old article on the machine and how it was programmed, from a 1998 issue of the IEEE Annals of the History of Computing.

There are many fascinating aspects to the machine and its utter simplicity, but one that struck me as I read the paper was that so many of the fundamental ideas of programming and practical computing were invented then and there. Indeed, the EDSAC was designed as a machine to experiment with programming, rather than as a machine for maximal computing performance.

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Pipeline Performance Simulator Anno 1960

I have just found what almost has to be the first cycle-accurate computer simulator in history. According to the article “Stretch-ing is Great Exercise — It Gets You in Shape to Win” by Frederick Brooks (the man behind the Mythical Man-Month) in the January-March 2010 issue of IEEE Annals of the History of Computing, IBM created a simulator of the pipeline for the IBM 7030 “Stretch” computer developed from 1956 to 1961 (photo from IBM.com).

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Eyjafjallajökull is Showing us Something

Wow. The eruption of Eyjafjallajökull in Iceland and the resulting ashcloud has had an effect that I would never ever have expected. A near-total closing down of the European airspace is such a drastic thing to happen to nobody seems to have expected. It has certainly not been included in the list of worst-case scenarios to plan for in company and government contingency plans. Where does this leave us? In a very interesting situation indeed. Worst-case, we will have to do without air travel for months.

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Matt’s Today in History: System/360

I am a regular listener to the Matt’s Today in History podcast. When Matt asked for contributions for this spring (in order to meet a goal of 500 podcasts before Summer) I did give some thought to what I could contribute. Looking over some books, I found one suitable Spring date: the launch of the IBM System/360 back in 1964. The resulting podcast is now live at Matt’s Today in History.

Please be kind to any mistakes… I am trying to paint a broad picture for a computer-history-ignorant audience here.

Off-Topic: Old and New Lego

During the Christmas holidays, I got the chance to compare my oldest child’s brand new Lego set with some from the mid-1980s. It is quite striking how much larger the things in the sets have become, and how much more affordable (in relative terms) Lego has become since then.

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It was Twenty Years Ago Today

Unless you have been living under a rock I guess the media deluge has made it clear that it was twenty years ago on November ninth that the Berlin Wall fell. Wow. Without a doubt the most momentous and important event that I have lived through. Not at all on the topic of this blog, but important enough to write some personal recollections about.

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When does Hardware Acceleration make Sense in Networking?

q_stampYes, when does hardware acceleration make sense in networking? Hardware acceleration in the common sense of “TCP offload”. This question was answered by a very nicely reasoned “no” in an article by Mike Odell in ACM Queue called “Network Front-End Processors, Yet Again“.

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Book review: ZX Spectrum BASIC

sinclairspectrum-preI just rediscovered my first computer, a Sinclair ZX Spectrum (good picture) which I bought back in 1983 or 1984 (I have no trace of the exact date, unfortunately). The machine was a perfect machine to learn programming on in my opinion, consisting of little more than a Z80 processor with memory, bit-mapped display (with a famously odd-ball addressing scheme and color handling) and ultra-simple sound output and input. Most of my friends in the end bought Commodore C64 machines, which had more powerful graphics and sound hardware, but a processor that was much less fun to program.

The Spectrum came with a built-in BASIC interpreter that are up the bottom 16kB of the 64kB addressing space. The BASIC was actually fairly powerful and easy-to-use, and included a very fun programming textbook. I just reread that textbook, and it is quite strikingly well-written and manages to cover both basic computer-science-style programming and deep close-to-the-machine and real-time programming in a compact 150 pages. There is no credit to a particular author in the book I have (Swedish translation by a group of people at Ord & Form here in Uppsala), but an online scan credits Steven Vickers.

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Marketing a Paper Magazine with a Podcast

I just found a fairly interesting podcast that offers a nice example on how do marketing for paper-based magazines using digital ephemeral technology. The ancient warfare magazine has a podcast that accompanies each issue, where a set of history buffs discuss around the theme of the current issue of the magazine.

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Off-Topic: Vista, Laserwriter 12/640 PS, and FoxIt

laserwriter12640I have an old Apple LaserWriter 12/640 PS network printer at home that I bought back in 1997. In those days, I had a PowerBook G3 at 266 MHz, Windows NT was new, and my work computer was one of Sweden’s first 300 MHz Pentium II machines… since then, my home machines have moved from MacOS 8 to Windows NT 4 to Windows 2000 to Windows XP and now Windows Vista 32- and 64-bit. But the trusty LaserWriter remains, keeps printing, and is still on its first toner cartridge!

However, moving to Vista has made the printing bit harder.

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The Details of Speed

I just read a fairly interesting book about the British Spitfire fighter plane of World War 2. The war bits were fairly boring, actually, but the development story was all the more interesting. I find it fascinating to read about how aviation engineers in the 1930s experiment and guess their way from the slow unwiedly biplanes of World War 1 and the 1920s to the sleek very fast aircraft of 1940 and beyond. It is a story that also has something tell us about contemporary software development and optimization.

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Virtual Platforms for Late Hardware and the Winds of History

As might be evident from this blog, I do have a certain interest in history and the history of computing in particular. One aspect where computing and history collide in a not-so-nice way today is in the archiving of digital data for the long term. I just read an article at Forskning och Framsteg where they discuss some of the issues that use of digital computer systems and digital non-physical documents have on the long-term archival of our intellectual world of today. Basically, digital archives tend to rot in a variety of ways. I think virtual platform technology could play a role in preserving our digital heritage for the future.

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The 1970 rule strikes again: Virtual Platform Principles in 1967

Being a bit of a computer history buff, I am often struck by how most key concepts and ideas in computer science and computer architecture were all invented in some form or the other before 1970. And commonly by IBM. This goes for caches, virtual memory, pipelining, out-of-order execution, virtual machines, operating systems, multitasking, byte-code machines, etc. Even so, I have found a quite extraordinary example of this that actually surprised me in its range of modern techniques employed. This is a follow-up to a previous post, after having actually digested the paper I talked about earlier.

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Virtual Platform by Virtualization Extensions — 1969

By means of a trip down virtualization history, I found a real gem in 1969 paper called A program simulator by partial interpretation, by Kazuhiro Fuchi, Hozumi Tanaka, Yuriko Manago, Toshitsugu Yuba of the Japanese Government Electrotechnical Laboratory. It was published at the second symposium on Operating systems principles (SOSP) in 1969. It describes a system where regular target instructions are directly interpreted, and any privileged instructions are trapped and simulated. Very similar to how VmWare does it for x86, or any other modern virtualization solution.

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A logo from 1996 and simulation for archival purposes

Back in 1996, DVP celebrated its 15th anniversary. When looking through my digital and paper archive, I found this gem: DVP 15 årThe official badge and logo for the 1996 anniversary! We also produced some mouse pads with this logo on them, one of which I still use for my daily job. Pretty good quality I must say.

The picture shown here was saved as GIF for use on the web. But scarily enough, apart from a few more GIF files, I could not open or even understand the file type of most of the files from that time, only ten years ago. Our digital archives are not very robust — more on that below.

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The Simulation of the first Amiga Custom Chips (1983)

ArsTechnica is running a history of the Amiga, and in part 3, “The first prototype” they describe a really interesting “simulation” solution for the custom chips in the first Amiga. This is in 1982-83, and there are no VHDL or Verilog simulators, nor any other EDA tools as we know them today. Even if they were, the Amiga company would not have been able to afford them. So in order to test their design, the Amiga engineers built chip replicas using breadboards and discrete logic chips. All in all, 7200 chips and a very large numbers of wires. Quite fascinating stuff, and they did manage to interface the main 68000 CPU to the breadboards and get a fully functional if a bit slow simulation of a complete Amiga computer with all its unique custom chips.

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Matts Today in History: The Vasa Sinks, August 10, 1628

Matts Today in History: The Vasa Sinks, August 10, 1628
is the latest installment in the very good and long-running PodCast called “Matt’s Today in History”. I really appreciate the effort going into the production of it, and the perserverance of Matt in keeping it up for more than two years.

This particular issue was interesting in two regards.

First, I suggested the topic.

Second, it featured what at least seemed like real paid advertising at the start. This is thanks to PodShow, the “media network” used to distribute this podcast. The deal behind PodShow is quite simple fo the podcaster: you get bandwitdh for free, in return for the possibility of there being advertising inserted into the audio.

The reasoning behind PodShow is nicely explained in a podcast from the Stanford Technology Ventures Entrepreneurial Thought Leaders series. Here, Ron Bloom and Ray Lane of PodShow describe the way PodShow got started and just what it is. Basically, they are building a new media company, to compete with radio and television. It is not just a nice place to find podcasts. Recommended listen for anyone interested in just how podcasting can be monetized. They describe how their staff constantly monitors the various shows that they carry, and find those popular and targeted enough to carry some paid advertising. Other shows carry intros and pointers to various other PodShow shows, to drive audience to more popular properties.

Thus, the conclusion must be that Matt’s Today in History has reached some threshold of audience that makes it valuable enough to carry advertising. Great job, and a sure sign of popularity of the podcast.