How important are ...

Could probably play a symphony with enough of them!

Had computing and / or electronics been available as an A level option in

1967, then I would have opted for them, but had to make do with maintaining the school "computer" which was 200 NOR gates with a patch panel, that was usually configured as a binary adder.

However, I digress. I would have been the prototypical nerd / geek of the day, and having no interest whatsoever in current affairs managed to get off General Studies by spending Friday afternoons unjamming the rotary hand-cranked calculators. This I did by some disassembly, and to prove that my repair was efficacious, to test it by following the algorithm to evaluate a square root (the details of which have slipped my memory but depended on the fact that the square of N was the sum of the first N odd numbers. eg, the square of 3 is 9 which is made up of 1 + 3 + 5. It was a subtractive process and relied on multiples of 10 squared, so the square of 90000 is 10000 + 30000 + 50000 and so on)

Bringing this back on topic, how does one ensure that for one's garden railway that the roots of the support posts are square? :-)

Oops! the square of 30000, which is 90000 is the sum of 10000 + 30000 +

50000

When I was in my final year at Primary school circa 1968 the head teacher* bought something like that. I can only think he was having a spot of indulgence and had wanted one, or may be it was for doing the school accounts on and he only taught me to use it in passing. As the school was a 2 room building in an agricultural village there was not a huge number of candidates who would go on to careers which would involve such things. There were only six of us in a year so it shows how small it was.

• This chap was everything a teacher should be. A girl and myself were more academic than most of the others and read through the school book allocation in days,so the teacher arranged that it was ok for us to pop outside to the traveling library once a week and choose our own. On another occasion I was late which was rare ,I usually cycled the 3 miles in. That Day I got a lift in on one of the areas last working Steam Rollers. The driver had asked to leave it in our yard the night before,cycled home and arrived back early to build up steam again. It was slower than my bike so I was late but it was an opportunity not to be missed. My teacher on hearing the reason dashed out and arranged with the driver that around lunchtime the pupils could go and see the machine. They got a history lesson on Rollers and road making, a physics lesson on how a steam engine works and a chance to witness a final glimpse at a way of working life that was fading fast. All in a practical demonstration which though only about 40 mins long probaby taught more than hours of book work. G.Harman

Some of the support posts to my garden railway were not square (to the line of the layout) when they were installed, so they ended up twisted. As they get older, and things tend to decay, goodness only knows how they untwist, and I daren't investigate in case I do something nasty to them. One thing I have learnt after ten years is that everything is OK until you come to make alterations, when it immediately falls to bits. The trackwork will withstand fairly heavy-handed track cleaning, but try to lift it, and you've got to replace it with new.

Oops-squared!! the square of 30000 is 900000000; the square of 300 is

90000.

In my student days in Manchester, I got to program the University's Atlas computer using both Atlas Autocode and Mercury Autocode, wheres the people in the physics department didn't have time for all that computer-science stuff (as we would call it now) and just used Fortran.

(Red-faced) So much of maths is 3.141592...... in the sky!

My degree course (electronics) used the PDP-8 as the basis of hardware design, and some of the labs required PDP-8 assembly language,

Spent the first 10 years of my career as a softy doing PDP-11 assembly language (after 1 year of hardware design)

I have a lot of tree roots in the garden and it is quite a stony soil. To avoid digging two far amongst the routes I hammered in met posts and fixed the wooden supports in those. Some met post hit stones while being driven in and went out of line but were still okay or supporting a track about 14" above the ground. My problem arose when it came to running a Hornby live steamer. The circuit while appearing reasonably level actually had a slight down gradient at point. The Live steamer would speed up a bit and with

10 on pushing it fly off into the bushes on the curve. I'm in the process of a relevelling exercise and and using the pond viaduct as a datum using another old tool for doing it. A clear hosepipe as a water level. Unlike new fangled things like laser levels it will go around the bushes and shrubs. What I was really after was some sort of support that could be adjusted easily and ended up using these supported on a small concrete pads. With the ease of adjustment I should be to get the whole circuit pretty level. Normally the thing are are darned expensive but I found a chap on Ebay selling them at 10 for £20. He still has a hundred or so left in case anybody wants copy the idea.

G.Harman

Remember them well, they were all we had in the Physical Chemistry lab in the late 60s, and we had to do Raman spectroscopy calculations to about 12 SF using them (as we were looking at tiny differences we needed the precision).

IIRC, to divide you cranked backwards until the bell pinged, then went back one turn, the bell signalled the remainder had gone negative.

Actually these things were a bit of a come down for me; I had spent most of the year before going up working at ICI, where we used an electromechanical version of these machines. You just needed to sit there and watch it chunder away (and make sure it didn't vibrate itself off the bench).

I went back the following year to the radiochemical lab where they had a Wang electronic calculator - size of a large-ish laser printer, functionality about that of a pocket programmable calculator, probably cost £10k+. In 1972 or 73, a fellow research student bought a Sinclair pocket calculator *kit* for about 50 quid (about a month's research grant), and had real trouble putting it together.

David

Wot a lot of we ageing ex scientists / engineers / computists now doing railway modelling!

[...]

IIRC, somebody wrote a piece that included typewriters.

Wolf K.

Right!

Thanks, Wolf K.

You couldn't do that these days without filling in reams of forms and risk assessments, by which time the roller has, er, rolled off :-)

In, presumably, 1981, I was doing lunchtime computer stuff at school (I was too old to start the computing course proper) and the teacher gave me a ZX81 *kit* to assemble - I would have been about 15/16. I was ever so chuffed that it worked when turned on, then I had to build the 16K RAM pack for it as well! I'd already been fiddling about soldering things for a few years by that stage, and don't really seem to have ever stopped :-)

"Do it first, ask forgiveness afterwards."

Wolf K.

They not only had the buttons to press but also a big crank handle on the side to turn - I guess that alleviated any RSI symptoms. I think the typewriterish carriage went all by itself. It was the first mechanical thing I ever felt no need to investigate!

Greg.P.

True - getting back to what we enjoyed doing as kids!

Our one had fractions as well - a whole row of separate buttons. That was useful as all our material lengths were in yards, half yards, quarter yards eigth yards, sixteenth yards and thirtyseconds of yards.

Greg.P.

A thicknesser and a planing machine should be able to achieve a sufficiently accurate result.