Retro computers,Vectorworks,B-splines and David Bernard Lewis Stephens

I guess it’s that time of year that you think about the people who are no longer with us. I was discussing the pre-historic age of computing with my eldest recently and mentioned that the first personal computer I can remember covetting was the Commodore Pet

Commodore Pet from 1977 (Image copyright Wikipedia)

Commodore Pet from 1977 (Image copyright Wikipedia)

Well anyway, my father David Bernard Lewis Stephens (1936-2005 RIP) was a mathematics and computing lecturer at Chelsea and then Kings College London. Initially working on huge rooms of computers where bearded students would diligently make posters of topless girls soley from alphanumeric characters. He saw back in the 70’s the future of computing would move away from these large banks of rooms into a computer that would sit on a desk.

He pioneered the purchase and use of a personal computer at Kings College in the late 70’s and after thorough research he purchased for the department a Rair Black Box, well anyway I wondered if there was anything on ebay that would be a momento of these days of computing and ended up buying an originar advertisement for the Rair Black Box that I’m going to mount on the wall and remember my dad by (at the time of writing it hasn’t arrived yet but below is the photo of it):

Rair Black Box

Rair Black Box

So what did my dad use it for ? Remembering back he would be writing mathematics equations in Fortran and Pascal and two of which I remember distinctly, where my fathers work was presented to Anne, the Princess Royal was on b-splines and tangents.

Let’s look at a spline in more detail; a spline was originally an elastic ruler that was bent to pass through a series of pre-defined points. My father would write a program that would allow you to input input a sequence of x & y coordinates and the Rair black box would calculate and draw the resultant spline. Here’s some of the mathematics behind the programming from Wikipedia

Now fast forward 35 years and I’m using the same calculations to draw splines between a sequence of similar coordinates in my CAD software.

Below you can see a screen grab from Vectorworks where I have added some loci to the drawing and then clicked between them with the Polyline by Cubic Spline tool. Within a few seconds I have created the same, beautiful spline between these points. Most of the time I take this action without thinking yet today, I remembered back to what my father did on that Rair Black Box.

VectorWorks polyline by spline

VectorWorks polyline by spline

David Bernard Lewis Stephens, 1936 – 2005 RIP

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