# What an electronic calculator!



## Venusian Broon (Nov 30, 2017)

For the young 'uns to give you an idea of what 'high tech' was in the early late 1960's-70's.






I was alive when Cliff Stoll used this in college....just


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## Kerrybuchanan (Nov 30, 2017)

Wow. Just wow.


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## Foxbat (Nov 30, 2017)

I remember using a slide rule in the 70s.
Again, for the young 'uns
Slide rule - Wikipedia


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## Kerrybuchanan (Nov 30, 2017)

I remember the slide rule, too. And log, sine and cos tables.


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## Venusian Broon (Nov 30, 2017)

Foxbat said:


> I remember using a slide rule in the 70s.
> Again, for the young 'uns
> Slide rule - Wikipedia



Jeez, you wonder why that tech died out 

(By the time I got to primary school in the mid-70's we were all decimal, SI and there wasn't a slide rule in sight! I think I got my first proper calculator, a white Casio fx-82, aged ten. Mind you, they are mostly obsolete now too....)


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## Ursa major (Nov 30, 2017)

The best thing about using the slide rule was that it taught** one to estimate the magnitude of the answer (which can be handy when one has punched/typed a decimal point in the wrong place in a number into the calculator/spreadsheet).


** - I was taught this in the first year of secondary school back in 1968/69. It's so long ago, it's no wonder I'm always up the creak... though not necessarily without a piddle....  (Yes, I mistype words as well as numbers. )


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## Harpo (Nov 30, 2017)

I did my maths O Level in 1978, with a slide rule. Everyone else had calculators.


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## Parson (Nov 30, 2017)

Very interesting. In 1975 I bought my first electronic calculator $30.00. It came in a nice leather case and I thought I had the world by the tail as I was figuring out percentages for my high school students. Now.... they hand out calculators (sans leather case) as free promo items.


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## Ursa major (Nov 30, 2017)

My first calculator (which may, or may not, be in the loft):





It came with a booklet that explained how one could use it to perform other functions. (I vaguely recall that one of these was to calculate the cube root of a number.)

_Original image from Wikipedia; created by Bubba73._


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## Dave (Nov 30, 2017)

Yes, we were taught to use slide rules and log tables at school. I think I was the final year that had to buy a slide rule in junior school before we all were using calculators. Calculators were expensive though and not everyone could afford them, so log tables continued for a little while longer.

I just wanted to draw attention to the work of the General Post Office Engineers at Bletchley Park, including Thomas _"Tommy"_ Harold Flowers, who designed and built _Colossus_, the world's first programmable electronic digital computer in 1943-45 using only valve technology. They are often forgotten, partly because they are now frequently overshadowed by the work there of the cryptanalysts, and notably of Alan Turing; and partly because their work was still kept as an official secret until 1974, allowing the American ENIAC machine to steal their thunder.


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## Dave (Nov 30, 2017)

This is the rebuilt Colossus at Bletchley Park.


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## Foxbat (Dec 1, 2017)

Dave said:


> Yes, we were taught to use slide rules and log tables at school. I think I was the final year that had to buy a slide rule in junior school before we all were using calculators. Calculators were expensive though and not everyone could afford them, so log tables continued for a little while longer.


Yep. Same here. I think my first actual calculator (which I bought just in time for college) was a Texas with the red led display. The first thing I learned was if you turned it upside down, you could make it spell words like 'BOOBS'  So much for the advancement of Mankind...


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## HanaBi (Dec 1, 2017)

Another Slide rule & log book pupil from back in the late 70s. 

I could never understand slide rules, and the only purpose I could see was to scratch my back or poke the person sitting in front of me (Mandy Harrison I think her name was); slide rules also made good catapults in class too!

My first calculator was a Sinclair. Great little machine that we could use in class but not during our "O" Level exams


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## reiver33 (Dec 1, 2017)

The first calculator I had used 4 x AA batteries, with a few hours life, and sported a hard-wired VAT button (which couldn't be re-programmed).


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## mosaix (Dec 1, 2017)

It’s a Sumlock Anita. I saw my first one at The Business Efficiency Exhibiton in Manchester in 1963. 

It was star of the art stuff in those days.


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## Vertigo (Dec 1, 2017)

I learnt on slide rule and log tables. No calculators were permitted until I got to university and then they weren't permitted in exams if they had any memory in them.


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## mosaix (Dec 1, 2017)

Anyone remember delay-loops?

A delay-loop was a wire loop that served as a low-capacity memory for calculators and other electronic equipment. Binary digits were sent as a signal down the loop in a continuous read-write operation. The length of the loop determining the size of the memory.


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## Venusian Broon (Dec 1, 2017)

mosaix said:


> Anyone remember delay-loops?
> 
> A delay-loop was a wire loop that served as a low-capacity memory for calculators and other electronic equipment. Binary digits were sent as a signal down the loop in a continuous read-write operation. The length of the loop determining the size of the memory.



They discuss it in the video - the calculator has a loop of piano wire that is hit and then a microphone picks up the bit that has been sent a bit later.


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## mosaix (Dec 1, 2017)

Venusian Broon said:


> They discuss it in the video - the calculator has a loop of piano wire that is hit and then a microphone picks up the bit that has been sent a bit later.



Didn't realise that, VB. For me, the video has no sound so didn't fully get it all.


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## Venusian Broon (Dec 1, 2017)

He opens up the memory unit at around 2 mins 10 secs and shows the inner secrets.


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## Foxbat (Dec 1, 2017)

Venusian Broon said:


> They discuss it in the video - the calculator has a loop of piano wire that is hit and then a microphone picks up the bit that has been sent a bit later.


That's really interesting because a spring reverb works on roughly the same principle.


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## Venusian Broon (Dec 1, 2017)

Foxbat said:


> That's really interesting because a spring reverb works on roughly the same principle.


Possibly exactly where they 'nicked' it from - they just converted it from analogue to digital!


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## Danny McG (Dec 1, 2017)

Venusian Broon said:


> For the young 'uns to give you an idea of what 'high tech' was in the early late 1960's-70's.
> 
> 
> 
> ...


Sitting in years 4 & 5 learning how to use these, oh yes indeedy!


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