Slide Rule

[pmcgee]

I've never had the chance to sit down with one.
Was it Apollo 13 (the movie) with the techies flying their slide-rules to calculate problems on the spot when the fecal matter impacted the rotary device?


http://www.youtube.com/watch?v=waiprjueVpQ

[chrisb691]

Still have mine from school somewhere, didn't have portable calculators back then. :D

[Big Shed]

I worked with one of these (http://www.sciencemuseum.org.uk/broughttolife/objects/display.aspx?id=5315) for quite a few years.

Also had one of these (http://en.wikipedia.org/wiki/Facit) on my desk.

Then in the mid 70s I got my first handheld electronic calculator, an Adler similar to this one (http://www.vintagecalculators.com/html/adler_lady___sir.html). Cost an arm and a leg, $80-90 as I seem to remember and had fewer functions than the $2 shop variety today.

[jimbur]

Still have a couple of mine from school and uni. Too well made to throw away even though they're completely superseded.

[BobL]

I did my undergrad degree with a slide rule. Got my first calc to take my educational statistics exam. Damn thing used to chew through batteries and they went flat mid exam luckily I had brought along my slide rule!

[ian]

Then in the mid 70s I got my first handheld electronic calculator, and Adler similar to this one (http://www.vintagecalculators.com/html/adler_lady___sir.html). Cost an arm and a leg, $80-90 as I seem to remember and had fewer functions than the $2 shop variety today.
you got off lightly

my first calculator cost something like $240 (in 1974 $) --equivalent to about $1900 in today's dollars, but not only could it add, subtract, multiply and divide, it could do trigonometry functions.

[Bushmiller]

not only could it add, subtract, multiply and divide, it could do trigonometry functions.

I think they were, and still are, referred to as the "scientific" versions. I still have and use my scientific calculator, but it was from a slightly later era.

Regards
Paul

[AlexS]

I still occasionally amuse the students by doing calculations as quickly on my circular slide rule as they can on their calculators. Also used to use the Facit at work, and in quiet times, we youngsters used to have Facit races, to see who could crank them the fastest. We also had a Marchant, which was sort of like an electrical Facit. Every so often it would seize up, so a squirt of WD40 int the innards would clear it.....or perhaps it was the explosion when the motor sparked.

[neilyeag]

Funny I was just talking about this with some one the other day. When I was in engineering school, also early 70's there were a few calculators around, I think my father had an HP-55. I think the thing cost about US $400 at the time. Wow. At Purdue, at the time they would not allow any calculators to be used in the classroom, or with exams. Slide rules only. Freshman engineering students actually had a full semester of classes on slide rules.

I had a beautiful slide rule that I used that was my fathers when he was in engineering school. Alas somewhere along the way I lost it.

Neil

[BobL]

My favorite mobile phone app is the HP41CV emulator with RPN data entry and that is my standard go-to calculator as I know how to drive these pretty fast. I still have my original HP41CV with the little magnetic card reader - at one stage I had a nuclear reactor model running on it that would take around 16 hours to run - about half of this was because the model itself could not be all held in memory and stuff had to be written temporarily off to magnetic cards. When the first 8088 PCs came out the nuclear model interim data could be stored on the HUGE 20 Mb HD so it ran in less than 10 minutes so I expanded the model (more variables and wider parameter space) and it then took over an hour to run. When the 386 PCs came out with bigger memories the whole model matrix could be held and worked on in memory so comp time came down down to under 3 minutes. I stopped pursuing the model at that point but I assume it would be down to seconds by now.

[ian]

my first calculator cost something like $240 (in 1974 $) --equivalent to about $1900 in today's dollars, but not only could it add, subtract, multiply and divide, it could do trigonometry functions.

I think they were, and still are, referred to as the "scientific" versions. I still have and use my scientific calculator, but it was from a slightly later era.
When I said add, subtract, multiply and divide I was thinking of one of these
http://www.hpmuseum.org/3qs/35v33q.jpg



Mine was one of these and it could handle polar notation and (once you knew how) working with i {= Square root(-1)} was a breeze

http://www.hpmuseum.org/45.jpg

and for all the youngsters, the early to mid 70s HP calculators didn't use brackets for nested formulas

[artme]

Never learned to use a sly drool or scientific calculator.

What couldn't be reasonably done in my head or longhand
was done with log and trig tables.

[Mr Brush]

I guess I was lucky to go through school (in the UK) just as everything was changing, so got to try both sides of things....

Started maths with a sliderule, then basic 4 function calculators came in about midway through my education. Anyone remember those Sinclair Scientific build it yourself calculator kits? :oo:

I also started school using imperial measurements, and changed to metric halfway through. This means that I now freely switch between systems depending on which is easiest to visualise, e.g. 3mm, 1/4", 1cm, 1/2", etc. :D

Still use the Hewlett Packard 32S Scientific Calculator that saw me though Uni. Once you get used to their weird RPN number entry system, its hard to go back to a regular calculator !

[Ashore]

Ahhh polar notation , no wonder the yanks like the tv show jeopardy

[Mr Brush]

BobL - ahhh, the HP-41C calculator !!! I used to lust after one of those, but the budget would only run to a 32S.....:no:

[Mr Brush]

Of course, this also meant that we got pretty good at mental arithmetic, and rough 'n' ready ways of estimating stuff. Some of the basic trig comes in handy for day to day stuff.

These days I delight in giving junior cashiers a handful of change, then watching them struggle to add it up to make sure you've given them them enough.....it's a worry:rolleyes:

[Big Shed]

Ah yes, mental arithmetic, went the way of the dodo in education and should be on display in the museums next to the slide rules and calculators.

[BobL]

BobL - ahhh, the HP-41C calculator !!! I used to lust after one of those, but the budget would only run to a 32S.....:no:

Well you can now afford it, the App costs very litre and the interface is excellent, it even reproduces the little click sound that you get when you press the keys.

And there's even a new advanced version (i41CX+ (http://alsoftiphone.com/i41CXplus/)) with symbolic/algebraic capability.

[Mr Brush]

Thanks Bob - I had to go looking for the Android equivalent, but it looks like there are a few available.

Between the PC, smartphone , and my little Nexus 7 tablet, at this rate just about everything in my life will be "virtual". Apart from the tools of course......:D

I wonder how long it will be before someone comes up with a set of virtual workshop machines, for use with virtual timber?????? Mate this with Sketchup, and you have a complete virtual workflow (complete with realistic machine noises). Wouldn't be long before someone was writing a "Kickback" app for the iPhone though.....:oo:

[ian]

wouldn't be long before someone was writing a "kickback" app for the iphone though.....:oo:
:rofl:

[BobL]

During my time as a research supervisor I'd often be training students inside an ultra clean sample preparation facility where we extracted and purified elements from small amounts of sample . To enter the facility was a PITA as it meant washing hands, removing shoes and coats, donning tyvek overalls, bootees, cap and gloves and walking through two or three doors over sticky mats - not too quickly or the bootees would come off. The sample preparation involved use of 4 and 5 decimal place balances so it was not unusual to end up with dozens of 5 - 7 digit numbers which required simple arithmetic to make progress. Even though I would tell the students to bring a calculator (which was used inside a clean ziplock bag) invariably they would forget and as very few could do the arithmetic without one they would have to go and get their calculator. By the time they returned I would have completed the simple arithmetic longhand and moved on, which bewildered the students no end but they never forgot their calculator after that.

[AlexS]

My favorite mobile phone app is the HP41CV emulator with RPN data entry and that is my standard go-to calculator as I know how to drive these pretty fast. I still have my original HP41CV with the little magnetic card reader - at one stage I had a nuclear reactor model running on it that would take around 16 hours to run - about half of this was because the model itself could not be all held in memory and stuff had to be written temporarily off to magnetic cards.
The HP41CV was a good little calculator. A bloke I worked with had one, while I was working on a HP9845 desktop (if you had a big desk) 64K computer driving 2 plotters, external & internal printer and two 8" 1.1k floppy drives. I wrote a program so that you could type a HP41CV program into the HP9845 and the plotter would write the program in bar code that could be read by the HP41CV's wand.

I was a surveying student just before we were allowed to use electronic calculators, and also just as EDM gear was coming in, so the use of 7 & 13 digit tables and triangulation both become largely redundant with the use of calculators and trilateration. When I think of all those hours spent doing relatively simple spherical trig, which required pages of calculations using 7 digit tables, I think I should have deferred for a couple of years!:rolleyes:

In the early days of calculators, I once had to write a tender for a four-function calculator. Finished up getting a 13 digit one with nixie-cube display. Anyone remember them?

[artme]

Ahhh - mental arithmetic. One thing that ought to be compulsory!!!

i have seen any number of young people who cannot do a simple
estimation using their scone. One reason for this is that we seem
to have scorned the notion that FACTS are actually useful building
blocks. Tables are not given the time and importance they deserve.

Without the knowledge of simple arithmetical tables you can't work
efficiently. It's like asking someone to dig a hole without a shovel.

[Ashore]

I still use this one

[artme]

I still use this one

When do you graduate to counters????:D:q

[The Bleeder]

Still got all of my slide rulers. If I get them out of the desk draw now they will still work. (brain hasn't had it yet)

Best one of mine was a 'circular' slide rule.

[pmcgee]

There's probably stuff here that - like old woodworking techniques - should be preserved and taught.

Also ... it's cool how this all ultimately also relates to woodwork ...

259794

[Wizened of Oz]

A jibe from one of my lecturers in the 1950s:

"An engineer is someone who multiplies 2 by 2 on the slide rule

And gets 3.99"

[AlexS]

"An engineer is someone who multiplies 2 by 2 on the slide rule

And gets 3.99"
:clap::clap::clap: