Welcome to the latest installment of the Brief Bio series, where I'm writing up very informal biographies about major figures in the history of computers. Please take a look at the Brief Bio archive, and feel free to leave corrections and omissions in the comments.

Charles Babbage

Like Pascal, Leibniz, and even Muller, Babbage was a man who was into a whole variety of fields: mathematics, economics, engineering, and so on. He was born in 1791 in London, on the day after Christmas, just a couple weeks after the Bill of Rights was ratified in the States. His father was a banker; and again, like the Pascal family, it's not difficult to imagine a house cluttered with mathematics. An Oxford tutor educated him and he was accepted at the University of Cambridge, but found their mathematics program to be disappointing (as shown in this photo):

A theme that I've noticed while researching Babbage is that his motivation seems to be one of replacing people (or rather, the innaccuracies and nuisances they cause). If t-shirts existed during his life time, I'm sure he would have at least considered purchasing "Go Away Or I Will Replace You...". Babbage spent some time later on in his life measuring and campaigning against public nuisances, even to the point of unpopularity. Babbage said that such nuisances destroyed up to 25% of his productivity. He's not only the ancestor of computing, but he's also the ancestor of the BOFH.

In 1820, he helped to form the (Royal) Astronomical Society. I believe that this is not because he was a romantic stargazer, but rather it was mostly a way for him to explore ways to reduce errors in astronomy (heavily used in sea navigation) with computing. He began work in 1822 on his now famous Difference Engine. He won an award 2 years later for inventing this machine (yes, he won an award from the very same organization that he helped to start). His machine was never actually completed until 1991, when it performed its first calculation.

Later on, Babbage went to work designing the Analytical Engine, which was to be a more general-purpose machine (a multitasker, as compared to the unitaskers of Pascal, Leibniz, Muller, and his own Difference Engine). Again, this machine (actually a collection of machines) was never completed. However, the designs include the use of punch cards as input, as well as branching, looping, and sequencing. Theoretically, this machine would be the first to ever be Turing-complete, and therefore the first ever device equivalent to what would generally be considered a computer.

The Analytics Engine concept marks the birth of computers, and even more importantly, marks the beginning of software (as will be explored later in the Ada Lovelace bio). However, this separation of concerns was just too abstract for the Victorian world, and he never got any funding to build the machine. Babbage died in 1871, still tinkering with his idea until the bitter end.

Plan 28 is a project to actually build an Analytical Engine. John Graham-Cumming gave a TEDx Talk about The Greatest Machine That Never Was:

Check out about 12 minutes in to see a part of the Analytical Engine in action. To compare this machine apples-to-apples with current computers, John Graham-Cumming has said that it would have 675 bytes of memory and a clock speed of 7 hz. That's hertz, not megahertz. Still, I'd call that very impressive: the Atari 2600 only has 128 bytes of RAM (albeit a much, much faster clock speed, and it's not the size of a locomotive).

Babbage's legacy lives on as an icon of computers and computing. In addition to the multiple academic institutions that bear his name, there's a crater on the moon named after him. Do you remember the video game/electronics store "Babbage's"? Named after him.

Of all the blog post titles I'd like to write, "Parsing XML in ASP classic" is definitely not at the top of my list. But sometimes you just have to suck it up. So here we go...

Given a string that contains XML (maybe the result of an Ajax request or the contents of some config file), let's get some values out of it.

Here's some sample XML that I'll be using:

Create a MSXML2.DOMDocument.6.0 object. Use its LoadXML method. You can then use the selectSingleNode and XPath to get values out. For instance, if I wanted the value for ShoeSize in the above XML, I could use an XPath of //@ShoeSize to get a node. Then use the text property of that node to get the value.

There ya go. If you aren't an XPath whiz, you can use this XPath tester to help you through it.

Welcome to another "Weekly Concerns". This is a post-a-week series of interesting links, relevant to programming and programmers. You can check out previous Weekly Concerns posts in the archive.

• The EFF is trying to make emails to Congress more effective. Traditionally, hand-written letters have always been seen as more effective. Let's see if this has any effect.
• WatchMojo's Top 10 Business Killed by the Internet.
• 8-bit maps of cities.
• Some rants about potentially inflammatory words or phrases when talking about software, from Jeremy Miller

If you have an interesting link that you'd like to see in Weekly Concerns, leave a comment or contact me.

Welcome to the latest installment of the Brief Bio series, where I'm writing up very informal biographies about major figures in the history of computers. Please take a look at the Brief Bio archive, and feel free to leave corrections and omissions in the comments.

J.H. Muller

Johann Helfrich von Muller, born in Germany in 1746 was the son of Lorenz Friedrich Muller, an architect and engineer.

There's scant sources of information on the internet available for Muller. It seems to be the case that he was a prolific inventor, engineering cool stuff like an immersive children's theater, a range finder, a barometer, and so on. Based on what little I can find, he seems to me very much in the same category as Thomas Edison: not really inventing or creating something brand new, but rather improving existing devices. He build a calculating machine which was an improved version of contemporary Philipp Hahn's machine, which in turn was based on Leibniz's stepped drum design.

His most notable invention is also the his most interesting in the context of computing: a difference engine. Muller's invention was described briefly in an appendix of a volume containing details of the calculating machine. This machine was only a proposal, and was never built. However, Charles Babbage would later go on to actually build a machine very much like the one described by J.H. Muller, and it's entirely possible that Babbage was at least partially inspired by Muller's work.

There is a book that was published in 1990: Glory and Failure: The Difference Engines of Johann Muller, Charles Babbage, and Georg and Edvard Sheutz. I suspect this book contains more informatiion about J.H. Muller than I could drum up, but it appears to be out of print, rather expensive, and lacking an ebook version. Unfortunately, that's beyond my budget for a single blog post, so J.H. Muller will remain mostly a footnote in the grander story of Charles Babbage for now.

Muller died in 1830.

Here's a little weirdness that I discovered this week. (I think this may just apply to ASP Classic but I'm not 100% sure).

I was writing some ASP Classic that reads some information from HTTP headers (which are put into the request from a mobile application). For some reason, the data wasn't showing up:

Turns out that the server replaces underscores with dashes. At first, this was just a wild guess on my part, but luckily it worked out.

A bit annoying, but I guess I learned something new!