This blog post was originally published at Intel. After it was retired from the Intel blog system, I reposted the full contents here in order to preserve the information for my own sake. And in case anyone has a pointer here.
How Simulation Started a Billion-Dollar Company
In the early 1990s, “PC graphics” was almost an oxymoron. If you wanted to do real graphics, you bought a “real machine”, most likely a Silicon Graphics workstation. At the PC price-point, fast hardware-accelerated 3D graphics wasn’t doable… until it suddenly was, thanks to Moore’s law. 3dfx was the first company to create fast 3D graphics for PC gamers. To get off the ground and get funded, 3dfx had to prove that their ideas were workable – and that proof came in the shape of a simulator. They used the simulator to demo their ideas, try out different design points, develop software pre-silicon, and validate the silicon once it arrived.
A comment on my old blog post about the history of reverse execution gave me a pointer to a fairly early example of replay debugging. The comment pointed at a 2002 blog post which in turn pointed at a 1999 LWN.net text which almost in passing describes a seemingly working record-replay debugger from 1995. The author was a Michael Elizabeth Chastain, of whom I have not managed to find any later traces.
Continue reading “A Replay Debugger from 1995!”
In a dusty bookshelf at work I found an ancient tome of wisdom, long abandoned by its previous owner. I was pointed to it by a fellow explorer of the dark arts of computer system design as something that you really should read. The book was “Fortress Rochester”, written by Frank Soltis, and published in 2001.
Continue reading “Fortress Rochester”
I just found and read an old text in the computer systems field, “Why Do Computers Fail and What Can Be Done About It?” , written by Jim Gray at Tandem Computers in 1985. It is a really nice overview of the issues that Tandem had encountered in their customer based, back in the early 1980s. The report is really a classic in the computer systems field, but I did not read it until now. Tandem was an early manufacturer of explicitly fault tolerant and highly reliable and available computers. In this technical report Jim Gray describes the basic principles of fault tolerance, and what kinds of faults happen in the field and that need to be tolerated.
Continue reading “Why DO Computers Fail?”
Apple just released their new iPhone 5s, where the biggest news is really the 64-bit processor core inside the new A7 SoC. Sixty four bits in a phone is a first, and it immediately raises the old question of just what 64 bits gives you. We saw this when AMD launched the Opteron and 64-bit x86 PC computing back in the early 2000’s, and in a less public market the same question was asked as 64-bit MIPS took huge chunks out of the networking processor market in the mid-2000s. It was never questioned in servers, however.
Continue reading “The First 64-bit Phone”
After some discussions at the S4D conference last week, I have some additional updates to the history and technologies of reverse execution. I have found one new commercial product at a much earlier point in time, and an interesting note on memory consistency.
Continue reading “Reverse Execution History Updates”
I recently read the classic book The Soul of a New Machine by Tracy Kidder. Even though it describes the project to build a machine that was launched more than 30 years ago, the story is still fresh and familiar. Corporate intrigue, managing difficult people, clever engineering, high pressure, all familiar ingredients in computing today just as it was back then. With my interesting in computer history and simulation, I was delighted to actually find a simulator in the story too! It was a cycle-accurate simulator of the design, programmed in 1979.
Continue reading ““Eagle” Cycle-Accurate Simulator Anno 1979″
In this final part of my series on the history of reverse debugging I will look at the products that launched around the mid-2000s and that finally made reverse debugging available in a commercially packaged product and not just research prototypes. Part one of this series provided a background on the technology and part two discussed various research papers on the topic going back to the early 1970s. The first commercial product featuring reverse debugging was launched in 2003, and then there have been a steady trickle of new products up until today.
Originally published in January 2012. Post updated 2012-09-28 with a revised timeline for Lauterbach CTS. Post updated 2016-04-05 to include Mozilla RR. Post updated 2016-12-26 to add Simulics. Post updated 2017-10-08 to add Microsoft WinDbg. Post updated 2018-07-28 to add Borland Turbo Debugger.
Continue reading “Reverse History Part Three – Products”
This is the second post in my series on the history of reverse execution, covering various early research papers. It is clear that reverse debugging has been considered a good idea for a very long time. Sadly though, not a practical one (at the time). The idea is too obvious to be considered new. Here are some of the papers that I have found, going back before reverse debugging got started for real in actual products (around 2003) as well later on for interesting research papers that did not make it into products. It is worth noting that products/useful software has become more common in recent times as the way that reverse debugging ideas get expressed.
Continue reading “Reverse History Part Two – Research”
For some reason, when I think of reverse execution and debugging, the sound track that goes through my head is a UK novelty hit from 1987, “Star Trekkin” by the Firm. It contains the memorable line “we’re only going forward ’cause we can’t find reverse“. To me, that sums up the history of reverse debugging nicely. The only reason we are not all using it every day is that practical reverse debugging has not been available until quite recently. However, in the past ten years, I think we can say that software development has indeed found reverse. It took a while to get there, however. This is the first of a series of blog posts that will try to cover some of the history of reverse debugging. The text turned out to be so long that I had to break it up to make each post usefully short. Part two is about research, and part three about products.
Continue reading “Reverse History Part One”
On the very binary date of 11-11-11, my alma mater, the computer science (DV, for datavetenskap) education at Uppsala University celebrated its thirty years’ anniversary. It was a great classic student party in the evening with a nice mix of old alumni and fresh-faced students. Lots of singing and some nice skits on stage. Great fun, and my voice has still not recovered. It also got me thinking about it is that we really do as computer scientists.
Continue reading “DV* 30 Years”
Just for fun, I tried to surf the web of today using a Netscape 4 browser from 2001.
The result: not exactly useful. Netscape 4 was bad back then, and it does not work at all with the current style of web coding.
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.
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.
Continue reading “Steve Furber: Emulated BBC Micro on Archimedes on PC”
There is a new post at my Wind River blog, about some computing history. Wind River turns thirty this year, Simics twenty, and simulation for debug (and probably debug in general) turns sixty. Computing has come a long way.