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When I chose Manchester University for my Computer Science MSc, it was partially because of its reputation but I realized I didn’t actually know anything specific about that legacy.

I thought I’d find out a little more about some of the computing cornerstones that were laid in Manchester’s labs. Did you know that the first Random Access Memory was created there? Fast, random access memory is a core part of computer systems today. Having enough of it is crucial to making your laptop or desktop run all those applications quickly for you.

The Williams (or Williams-Kilburn) Tube was the first random access memory that could access at speeds suitable for a computer. It was the ancestor of the multi-gigabyte cards you’ll find in your computer today.

Back in the days before TVs were two inches thick, the moving pictures on the screen were drawn by magnetic fields and streams of electrons in a glass tube called a Cathode Ray Tube, or CRT. Did you ever hold your hand near the screen of a CRT television and feel the static tingle? Somewhere around 1946, Tom Kilburn and Freddie Williams at Manchester University used the charge on a CRT’s phosphorescent coating to store ones and zeroes (effectively as dots), where they could be detected by a ‘pickup plate’ which lay over the ’screen’.

As the electron beam hit the screen, a positive charge would be left behind at that position. Not for long mind you, as the charge would dissipate, but the information read by the pickup plate was used to refresh the tube before the charge had chance to leak away. This refreshing process is still required by the RAM chips in your computer today.

If you’re interested in knowing more, you can read all about it on Wikipedia and computer50.org, the sources I used to get this information.

To test the Williams Tube, the folks at Manchester built the first stored-program computer, a pretty important milestone in its own right. Maybe more on that some other time.

Paul Brabban Computer Science, history, manchester

The material for day 4 focussed on Business Process Modelling. This sits orthogonally to Patterns for e-Business, defining business functions over their architecture.

There are two notations for Business Processes put forward – BPMN and UML Use Case/Activity Diagrams. My part of the coursework assignment is to apply BPM to the johnlewis.com some processes on the website, for which I’ve chosen Activity Diagrams and Visual Paradigm for UML. I did take a look at the implementations of BPMN, but I found a familiar pattern – they either didn’t work or cost $$$. Fortunately, VP is still serving me well.

The lab session was spent working with my team on the coursework and setting up tasks for the rest of week. As we’re producing a large report and taking different sections, we’ve set up a Google Docs site to drop working drafts onto to help us collaborate. It’s the first time I’ve used Google Docs like this and so far I like it, it’s responsive, intuitive and it’s easy to share a folder with a group of people, so for this kind of work it’s looking good.

In other news, the marks for the Machine Learning module are in and I’m very happy to have passed! That’s two modules, or one-quarter of my MSc done.

Paul Brabban Computer Science, MSc

Today was hand-in day for the first part of this module’s coursework – to design a shop, based on four requirements, using Object-Oriented design principles. Specifically, we had to use the State, Strategy and Item Description patterns, although I also worked in a couple of other patterns I like – Decorator (solves problems of composing functionality using recursion) and Iterator (hides implementation details of collections behind a simple object you can only iterate over).

I quite enjoyed having a simple pet problem like this, with a real reason to work through some aspects of it. If you’re interested in having a go yourself, the assignment reminded me of the first pragprog Code Kata – Supermarket Pricing.

As a result of the coursework, I’ve found a UML tool I can live with – Visual Paradigm. I’ll probably do a bit of a review and compare with the other tools I tried soon, but suffice to say it was by some margin the most pleasant and easy-to-use tool of the 5 or 6 I tried. £40 needed to get rid of the invasive watermark, but it looks like when it comes to CASE tools you get what you pay for.

The lectures are proving tricky to keep on top of – the pace is kinda slow (maybe that’s just me), so I find myself struggling to maintain attention. Still, the lecture notes are very detailed, so I spent a a few hours reviewing last week’s notes creating myself some revision material. I’ve been using a piece of software called Freemind to do ‘mind-mapping’, something I found out about in a presentation by Steve Brett in last years’ unsheffield unconference. It seems to work pretty well for the way I do revision, here’s a screenshot if you’ve not seen a mind map before.

So anyway, it’s all good. Coursework part 2 starts now, two more lectures in this module.

Paul Brabban Computer Science, MSc