Don't Ruin Your Children

A project log for WITCH-E Decimal Based Computer

Document and create a modern replica of the Harwell Dekatron computer known as the WITCH

Dave's Dev LabDave's Dev Lab 10/20/2017 at 02:086 Comments

So my daughter was off to work and stopped by my office. She saw that I was experimenting with different cable routing paths, so she took a few minutes to draw a block diagram. For this phase of the project, there are 4 large sections of laser cut acrylic that would hold each of the modules. I was struggling to see how I could mount all the modules and get them connected. I really see the challenge of the early computer developers on how to route and connect all these modules together. Before Integrated Circuits (ICs), this was often referred to as the "Tyranny of Numbers". How do you exactly plan for the massive number of wiring connections between modules and make sure that the minimum number of necessary connections are made. It takes a completely different way of thinking to do this. The really scary part of this log post is that there was very little I had to explain to my daughter. She "just drew" this with little guidance, and I am thinking "wow! did I really inadvertently ruin my children with my nerdy projects?" Maybe... but at least she can laugh knowing that she is fully aware of how to use a soldering iron and can point out the obvious to other people.... ouch! Smells like chicken!


Ed S wrote 10/22/2017 at 18:19 point

It has drawbacks, but the penhold grip gives great accurate control.  Ahem.  Thanks for the link to Tyranny of Numbers - the history of integration is interesting, as a series of pressing problems to solve.  The inevitable march of progress is not such a good way to look at it.

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Dave's Dev Lab wrote 10/22/2017 at 19:26 point

indeed the whole purpose of the project was to get a really good feel for the challenges that the original designers and builders faced when making the WITCH a reality. they really didn't have any previous experience, or other projects to use as a reference, so it was all learn as you go...

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Ed S wrote 10/22/2017 at 20:03 point

Have you come across the book Faster than Thought? It's a compendium of papers, from 1953. Just a couple of years too late for the Harwell people!

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Dave's Dev Lab wrote 10/24/2017 at 20:12 point

Indeed I have a copy of "Faster Than Thought". In fact, it was where I first read of the Harwell WITCH back in 2008. The WITCH wasn't rediscovered until the fall of 2009. Chapter 9 is specifically for the Harwell WITCH, but under a different name since it wasn't known as the WITCH until it was donated to Wolverhampton University in 1957!

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Ed S wrote 10/24/2017 at 20:16 point

Ah - that's amazing!

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Dr. Cockroach wrote 10/20/2017 at 08:32 point

I had to shudder seeing that pic ;-)  Ruin, I would say blessed :-)

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