UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > General Vintage Technology > General Vintage Technology Discussions

Notices

General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc.

Closed Thread
 
Thread Tools
Old 11th Mar 2019, 6:26 pm   #61
Craig Sawyers
Dekatron
 
Craig Sawyers's Avatar
 
Join Date: Nov 2010
Location: Oxford, UK.
Posts: 4,941
Default Re: The slide rule

Quote:
Originally Posted by Andrew2 View Post
Anyone remember those mechanical pocket calcuators that you operated with a stylus? They were about the size of a modern calculator and had columns of ratchet-type things that you dragged down with the stylus. The answer appeared in a row of small windows.
These things were all the rage at the Grammar school I went to.
I've found a picture of something similar, but I think the one available in the shops around here was even cheaper and tinny.
That was precisely what I was describing earlier - it is called an Addiator. You could do additions and subtractions. Which is why they were attached to the back of Faber Castell slide rules. The FC type number for an Addiator version added an A to indicate that it came with an addiator.

Craig
Craig Sawyers is online now  
Old 11th Mar 2019, 6:57 pm   #62
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
Default Re: The slide rule

I was trained on a British Thornton slider in my first two years at grammar-school - along with five-figure logtables.

By the 'Upper-5th' form [for us who'd taken our O-levels a year or two early so were now doing the A-level syllabus a year or two early too] when we were doing serious physics and algebra/trig I'd persuaded my parents to buy me an H-P 65 calculator. My father claimed it against tax as a business-expense, having bought a few dozen similar calculators for his techies.
G6Tanuki is offline  
Old 11th Mar 2019, 7:02 pm   #63
ms660
Dekatron
 
ms660's Avatar
 
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
Default Re: The slide rule

All a slide rule reminds me of is Sam Cooke and Otis Redding....I'll get m'coat.

Lawrence.
ms660 is offline  
Old 11th Mar 2019, 7:38 pm   #64
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
Default Re: The slide rule

Quote:
Originally Posted by ms660 View Post
All a slide rule reminds me of is Sam Cooke and Otis Redding....I'll get m'coat.

Lawrence.
What a wonderful world this could be !
G6Tanuki is offline  
Old 11th Mar 2019, 9:21 pm   #65
The Philpott
Dekatron
 
The Philpott's Avatar
 
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,081
Default Re: The slide rule

On closer examination, judging by the vacant grooves in the edge,my car boot sale buy has a piece missing.. (The cursor?)
The care and adjustment instructions hark back to a time when things need not necessarily be thrown away at the first hint of trouble!

Speaking of having a piece missing....I too sat my Maths O Level in 1986..then again in 1987. Twice. Oh well, a C is still a pass i suppose.

Dave
Attached Thumbnails
Click image for larger version

Name:	DSC00987.jpg
Views:	74
Size:	81.8 KB
ID:	179764   Click image for larger version

Name:	DSC00988.jpg
Views:	69
Size:	53.5 KB
ID:	179765   Click image for larger version

Name:	DSC00990.jpg
Views:	71
Size:	47.8 KB
ID:	179766  
The Philpott is offline  
Old 11th Mar 2019, 9:53 pm   #66
MotorBikeLes
Nonode
 
Join Date: Dec 2012
Location: Kirk Michael, Isle of Man
Posts: 2,346
Default Re: The slide rule

I think I still have 4 or 5 slide rules, and if I get one out, I will still be able to use it.
At school, we learned to use logs, and a friend of the family gave me his book of 7 figure logs, which I still have now. It also had 7 figure "quarter squares" though without opening the book, I forget what they were used for. I think the book was originally intended for nautical use.
When I stater work, we had a "muldivo" "wind on" machine similar to that shown earlier. I could really rattle stuff out on that, multiplications or divisions as well as simple additions and subtractions.
We had a special slide rule made up by an earlier lab tech for doing water absorbtion, VDS and VFS (volumetric drying/firing shrinkage) for all the special brick testing we did.
In my next job, I needed to learn to use a slide rule for particle size analysis (a 6" Unique) and I quickly learned to use the C1 scale, making many calcs much quicker than with just C and D scales.
I decided to buy myself a 10" rule, and in a local "high end" stationers I found a real beauty. Aluminium, I seem to recall it was light yellow, but its cost was way too much for me, so I came away with a Blundell "Academy 302", in my hands now.A,B,C,C1,D, LL2, LL3, Sin, Tan, sin/tan(small angles) and of course the linear L scale. I never understood why that L scale was not an exact 10", allowing it to be used for measurements as well.
I have another one somewhere with a tapered edge with measurement (inches) on it, though that was a 5", so not appropriate.
Les.
From around 1960 to 1980, a 5" rule was in my top pocket at all times. Used daily, often many times daily.

Last edited by MotorBikeLes; 11th Mar 2019 at 9:56 pm. Reason: addendum
MotorBikeLes is offline  
Old 11th Mar 2019, 9:57 pm   #67
m0cemdave
Octode
 
Join Date: Feb 2009
Location: Bletchley, Buckinghamshire, UK.
Posts: 1,205
Default Re: The slide rule

I remember having one of those stylus operated things in the 60's. It added up pre-decimal currency and I seem to remember a "carry" was done by a kind of hooking motion with the stylus, at the end of the slot. Sadly long gone.

I still have the Thornton AA010 "Comprehensive" that I used at school, and also an Aristo 0968, as pictured earlier in this thread. The Aristo includes a ruler and a set of conversion tables stored in the case.

Last edited by m0cemdave; 11th Mar 2019 at 10:03 pm.
m0cemdave is offline  
Old 11th Mar 2019, 10:16 pm   #68
Damien VK3RX
Tetrode
 
Damien VK3RX's Avatar
 
Join Date: Apr 2017
Location: Woodend, Victoria, Australia.
Posts: 87
Default Re: The slide rule

Where I worked in the early 70's one of the foremen had a cylindrical slide rule.

I recall it was about 8-10" long and looked like a small telescope.

I'd never seen one of those before. A look on ebay suggests it may have been an Otis brand.
__________________
Damien
http://www.vk3rx.com/
Damien VK3RX is offline  
Old 11th Mar 2019, 10:21 pm   #69
Craig Sawyers
Dekatron
 
Craig Sawyers's Avatar
 
Join Date: Nov 2010
Location: Oxford, UK.
Posts: 4,941
Default Re: The slide rule

This is the current collection, with some notes on dates (where possible) and condition (only of some; not complete yet)

They span the date range of 1901 to 1977

I've really stopped collecting, but know myself well enough to realise that this is a rabbit hole I could easily go down again....

Craig
Attached Files
File Type: pdf Slide rules summary.pdf (228.5 KB, 66 views)

Last edited by Craig Sawyers; 11th Mar 2019 at 10:26 pm.
Craig Sawyers is online now  
Old 11th Mar 2019, 10:39 pm   #70
Dave Moll
Dekatron
 
Dave Moll's Avatar
 
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 6,118
Default Re: The slide rule

Quote:
Originally Posted by m0cemdave View Post
I remember having one of those stylus operated things in the 60's... I seem to remember a "carry" was done by a kind of hooking motion with the stylus, at the end of the slot.
Your memory is correct - you would slide the stylus across to the adjacent column in the "hook" to perform the carry.

The methodology of these effectively mirrored that of an abacus.
__________________
Mending is better than Ending (cf Brave New World by Aldous Huxley)

Last edited by Dave Moll; 11th Mar 2019 at 10:41 pm. Reason: comparison with abacus
Dave Moll is offline  
Old 11th Mar 2019, 11:28 pm   #71
Andrewausfa
Octode
 
Andrewausfa's Avatar
 
Join Date: Dec 2010
Location: St Ives, Cambridgeshire, UK.
Posts: 1,180
Default Re: The slide rule

Quote:
Originally Posted by Craig Sawyers View Post
this is a rabbit hole I could easily go down again.... Craig
I think you're down the hole Craig! Super collection!

Andrew
__________________
Invisible airwaves crackle with life. Or they should do.
BVWS Member
Andrewausfa is offline  
Old 12th Mar 2019, 12:29 am   #72
emeritus
Dekatron
 
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
Posts: 5,316
Default Re: The slide rule

Re #59, yes it was some time ago, in the late 1960's.
emeritus is offline  
Old 12th Mar 2019, 9:47 am   #73
M0FYA Andy
Nonode
 
Join Date: May 2007
Location: Preston, Lancashire, UK.
Posts: 2,510
Default Re: The slide rule

Here's one in my collection, of interest to me because it has an Air Ministry Stores Reference Number, 6E-272. Section 6E is for 'Miscellaneous Instruments'.
Attached Thumbnails
Click image for larger version

Name:	6E-272 Slide Rule pic 4.jpg
Views:	81
Size:	87.1 KB
ID:	179785   Click image for larger version

Name:	6E-272 Slide Rule pic 8.jpg
Views:	78
Size:	59.2 KB
ID:	179786  
M0FYA Andy is offline  
Old 12th Mar 2019, 11:46 am   #74
John10b
Nonode
 
Join Date: Nov 2016
Location: Aberaeron, Ceredigion, Wales, UK.
Posts: 2,869
Default Re: The slide rule

I wonder if that one would have been allowed into the exam room, with formulas written on it?
Cheers
John
John10b is online now  
Old 12th Mar 2019, 1:17 pm   #75
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
Default Re: The slide rule

As well as slide-rules, I always liked the rotary drill/tap/thread-size calculator things, such as: https://collection.maas.museum/object/381798

There were some more-sophisticated versions for specific applications that had _two_ overlapping wheels on different axles, with helices of holes in each wheel that you lined-up to read the result off. I remember one such beastie being for gas pressure/temperature calculations and the different helices being for the different gases (hydrogen, oxygen, methane, ammonia etc). The numbers for the Ammonia calculations were printed in green!
G6Tanuki is offline  
Old 12th Mar 2019, 7:41 pm   #76
The Philpott
Dekatron
 
The Philpott's Avatar
 
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,081
Default Re: The slide rule

Andy's post #73- appears to be a 'Unique' slide rule similar, but not the same as mine. The centre piece is wider and where my scale goes up to 10 his goes up to 11!
No War Dept. stock number on the rear, it merely says -Copyright-

Dave
The Philpott is offline  
Old 12th Mar 2019, 8:07 pm   #77
dr_nick
Triode
 
Join Date: Oct 2018
Location: South Lakeland, Cumbria, UK.
Posts: 47
Default Re: The slide rule

For MotorBikeLes:

Quarter Squares was a multiplication algorithm.

To multiply two integers using a quarter squares table:

1) find the sum and difference values between your integers
2) look up the quarter square values in the table (whose value is floor[n^2/4] - hence the name quarter square)
3) take the difference of the quarter square values

so for 5*7

1) sum and differences are 2 and 12
2) look up the quarter square values which are 1 and 36 respectively
3) take difference between the quarter square values is 36-1 = 35 = 5*7

Quarter Square (2) = floor[2^2/4] = 1
Quarter Square (12) = floor[12^2/4] = 36

Hope I've got that right - I believe that whilst some extensive tables were published, the quarter square algorithm found much more utility as a computer algorithm.

Much as I loved my slide rule (down to my last 5); I wouldn't swap for my RPN calculator.

Nick.
dr_nick is offline  
Old 12th Mar 2019, 10:45 pm   #78
M0FYA Andy
Nonode
 
Join Date: May 2007
Location: Preston, Lancashire, UK.
Posts: 2,510
Default Re: The slide rule

Quote:
Originally Posted by The Philpott View Post
Andy's post #73- appears to be a 'Unique' slide rule similar, but not the same as mine. The centre piece is wider and where my scale goes up to 10 his goes up to 11!
No War Dept. stock number on the rear, it merely says -Copyright-

Dave
It is indeed a 'Unique' rule, here's a picture of the other end. When I bought it the cursor was missing, so I swapped one from a standard similar rule.

Andy
Attached Thumbnails
Click image for larger version

Name:	6E-272 Slide Rule pic 3.jpg
Views:	47
Size:	81.0 KB
ID:	179828  
M0FYA Andy is offline  
Old 12th Mar 2019, 11:12 pm   #79
ronbryan
Octode
 
Join Date: Jan 2003
Location: Guildford, Surrey, UK.
Posts: 1,958
Default Re: The slide rule

I have this Produx German made mechanical calculator, similar in principle to the ones already posted and the instructions in German. It is operated by a stylus. The display digits are reset by pulling up a bar at the top of the calculator body. It belonged to my Dad but I never saw him use it.

I also have a British Thornton slide rule, used at college and somewhere a specially made CEGB slide rule for calculating telemeter settings. Telemeters were used to bring in data from transmission substations over telephone lines in CEGB days.

Ron
Attached Thumbnails
Click image for larger version

Name:	Produx-calculator-1_web.jpg
Views:	58
Size:	115.4 KB
ID:	179829   Click image for larger version

Name:	Instructions-1_web.jpg
Views:	44
Size:	56.4 KB
ID:	179830   Click image for larger version

Name:	Instructions-2_web.jpg
Views:	37
Size:	52.4 KB
ID:	179831  
ronbryan is offline  
Old 13th Mar 2019, 6:04 am   #80
TonyDuell
Dekatron
 
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,190
Default Re: The slide rule

Quote:
Originally Posted by dr_nick View Post
For MotorBikeLes:

Quarter Squares was a multiplication algorithm.

To multiply two integers using a quarter squares table:

1) find the sum and difference values between your integers
2) look up the quarter square values in the table (whose value is floor[n^2/4] - hence the name quarter square)
3) take the difference of the quarter square values

so for 5*7

1) sum and differences are 2 and 12
2) look up the quarter square values which are 1 and 36 respectively
3) take difference between the quarter square values is 36-1 = 35 = 5*7

Quarter Square (2) = floor[2^2/4] = 1
Quarter Square (12) = floor[12^2/4] = 36

Hope I've got that right - I believe that whilst some extensive tables were published, the quarter square algorithm found much more utility as a computer algorithm.

Nick.
I think that's right.

It comes from that facts that

(a+b)^2 = a^2 + 2ab + b^2

and

(a-b)^2 = a^2 - 2ab + b^2

so

(a+b)^2 - (a-b)^2 = 4ab

I've seen it done in hardware using a ROM lookup table for the squares and a set of full adders to calculate sums and differences. Of course dividing by 4 is trivial in binary. The advantage over a lookup table for products is the reduction in size of the table. To do an 8bit * 8bit multiplier lookup table you need a table of 65536 entries. But since the sum of 2 8 bit numbers is 9 bits or less you only need a 512 entry table of squares.
TonyDuell is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 12:26 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.