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Slide Rules. Collecting and discussing. 13

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Skogsgurra

Electrical
Mar 31, 2003
11,815
SE
Hello all,

You are invited to share views and thoughts about slide rules. I have been collecting these devices on a rather small scale and had fifteen of them when my collection took a quantum jump. I was visiting the local book store to buy a book on flowers (yes, flowers) when I happened to ask the store-keeper if he perhaps had any slide rules. He gave me a puzzled look and then said "Yes, I found a box with some forty old slide rules yesterday. I haven't decided what to do with them yet".

Need I say that I saved them from the scrapheap? I got a substantial addition to my collection at a price that we both were very pleased with. He because he got anything at all and I because I paid about a tenth of what I had expected to pay.

I have mostly European and Japanese slide rules. Faber-Castell, Aristo, Sun-Hemmi and some less known makes like Graphoplex (French), Diwa (Danish), Royal Slide Rule (British) and Eco Bra (can't make out from where it comes).

There is a certain standardisation among slide rules. There are the scale systems; Mannheim, Rietz, Darmstadt, Electro, Disponent and some other special systems. There is one that intrigues me. It is called Tachymeter and seems to have been used by surveyors. And there are probably many more that I haven't discovered yet.

The slide rules from the BHP era look very much the same except for the introduction of the Duplex slide rules in the late fifties/early sixties. That was also when some colour was added - except for the "reversed" scales (increasing from right to left instead of from left to right) which seems to have been coloured red for a very long time.

It was only AHP that design people started to make the slide rules more and more attractive. Mild colour coding, more scales and cursor lines, extra functions, friction areas to ease handling, table stands and more was added to keep a market that everyone probably already knew was lost. The last slide rules produced were sometimes monsters - or beauties - depending on your personal preferences. I, myself, think that the Faber-Castell 2/83 N (the N is important here) is a beauty. It is the longest 1 foot SR produced, I think. It has 30 scales and it even smells good!

Another favourite is the little FC 67/38b 400 grad Tachymeter. It is a favourite mostly because it is so enigmatic. What are sin.cos and cos2 scales used for? They are probably there for some very valid reason - as is the 1-cos2 scale. Anyone that has information about these scales?

Collecting slide rules appears to be the retired engineer's perfect hobby. We know a lot, but not all, about the objects. We can appreciate the good workmanship, the precision, the artistery and the ingenuity that went into their design and production. And we know how to use them!

There are a few other reasons that make them ideal collector's objects: They are no more produced. They are still available - although in limited quantity. They are not bulky - can be carried with you when meeting like-minded. There will probably never be a fake slide rule - it takes a very complex production facility to make slide rules and the last factory was closed in 1975.

It is a little like collecting Fabergé eggs - only so much cheaper and more interesting.

Comments and answers invited! Do you collect slide rules? Do you have specific knowledge about any special slide rule? What makes do you know about? How do you find them?

BHP = Before HP.

Gunnar Englund
 
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What with all this talk about 10" and 14" aluminum slide rules, I'm starting to feel a little inadequate! I saved a 4" bamboo Relay No. 403 from my father-in-law's yard sale.

I guess I could console myself with the ol' "Size doesn't matter" and "It's not what you have, it's how you use it" routine - but I've never used one! I've had calculators since elementary school. This thread has renewed my interest in learning, though.

It was made in Japan, and has A, B, CI, C, D, S, L, and T scales, with a semicircular magnifier. I also have the original box, the instruction booklet and a leather carrying case. My guess is my father-in-law got it sometime in the 1950's, either as an engineer in the U.S. Army, or as a Chemistry undergraduate.


 
I have seven, now in a glass case on the wall. Including my first one from high school and the top of the line Post Versalog I got for college. I preferred the Post models, which are bamboo with a plastic face rather than the metal type.
 
A four-incher is my wife's favourite (slide rule). She wants'em "cute".

All bamboo rules were made by Hemmi - that goes for Post as well as Relay.

A Miniature Slide Rule Relay No. 403 is not bad at all. Can be seen at 30 - 50 USD on the net.

Gunnar Englund
 
NEWS!

I happened to hear from a friend that there was an old book store only 200 miles from where I live and that there were around 50 slide rules there. So I went there yesterday. The guy was willing to sell and had summed up the original prices (from around 1970) and then he gave me a 50 percent rebate! I refused and payed him 100 percent. It was still a bargain. Found a Faber-castell 62/83 N (their pocket version of the top performer 2/83 N) and several other nice SRs. Also found eight with missing cursors - which made my day a little less fantastic. But still, 41 new ones, that's not bad.

Gunnar Englund
 
It must be some type of sickness you people have. Driving 200 miles one way to buy, refusing a discount, 50 slide rules.

I think I'll stick with model trains and planes. I just go to the corner hobby shop for those.

<Hoping you enjoy my satirical nature.>

--Scott

For some pleasure reading, try FAQ731-376
 
Short question: I have found a circular "slide rule" that is marked IWA 1638. It has very long scales and lots of units conversions. Anyone that has additional information on this one?

Gunnar Englund
 
Thanks! How did you find that one? After wading through several intermediate pages in German, you find this: and that came as a big surprise to me. The IWA 1638 was designed by a fellow countryman named Wern. Interesting, to say the least.

Gunnar Englund
 
BF&I --> brute force and ignorance

Google only came up with two hits, both from the same site. I know just enough German to determine that it was a relevant hit.

TTFN



 
skogsgurra
You should be able to tell us all about the history of mechanical calculators.
 
Uncle Sid (or am I mistaken?)

I certainly would like to do that. But I think that the band-width would be suffering. Also, I think that there are limits to the length of postings. And - I'm still learing - not an expert.

But it is an interesting subject. Why not start telling us about your slide rules and calculators - mechanical or electronic? Which ones do you have? What do/did you use them for? How did you get them?

Gunnar Englund
 
Yes, but I had told it to look "everywhere". It didn't. Using the international one works better. Lesson learned. Thanks.

Gunnar Englund
 
At school I hung a K&E Log Log Duplex Decitrig on my belt like all good Engineering Students. The thing cost $21 (1952) and you couldn't eat it. While in service in Japan I was stationed with what I would call slide rule wizard who had Relay make bunch of different rules with strange stacking of the scales. I have one 12" W & W left that has several more compressed scales. The name on the slide rules was Wallace & Wallace. He also had the first 0.7 mm mechanical collet pencils manufactured. I still have one from 1958. Came to find out later he was the CIA Station Chief. As stated before on my first job we had Frieden and Marchant mechanical calculators. I was the first to get one that would carry a sum and square a number. With this machine I became the darling of the group as I could handle Logarithms very well. Nearly burned me out when EVOP, Evolutionary Operation, became the vogue. 2^5 factorials repeated 5 or more times was tough. My first personal electronic calculator, in fact the first or second electronic calculator on site, was from Abercrobie & Fitch, it was a single digit 4 function job that cost $129. I also had the first calculator with memory. It was called the Sharp, 2 and 1/2 digits and had a single memory register, great stuff. The next one was also a Sharp that still had a single memory register but would extract a square root, even greater. From then on I stayed with the TI and others, stayed away from the HP side.
As I’ve stated before I liked the slide rule in meetings as you know that you were in trouble when half the group whipped them out after you had made a statement. We the all the stuff on the table today you never know what anyone is doing.
Also as stated before I got to work on the first engineering application on the IBM 360 at work.
The first multiple purchases of utility electronic calculators that were made by Singer, the sewing machine company. The display was nixie tubes. This was later change to a CRT.

While overseas I knew there were about 20 IBM tabulation machines in operation on the base but didn’t find out until later that there was mainframe working 24/7/365. Don’t know the make but it was big. One of the guys who worked with it told me many years later that if they lost air conditioning it cost about $80,000 to replace tubes and relays. This was in 1957.

It has been interesting watch the evolution of computing in engineering over the years from a very ragged start. When in college taking algebra I remember that we skipped over Boolean and Matrix Algebra. The comments were that we would never need it and if we wanted to we could take it as graduate course in our senior year, if we had time.
Most of the people on this site missed the best part of computing.
Like a lot companies we suffer with management that consider a computer a luxury and wasn’t needed by engineers. When we did get one or two 10 megs of memory was something else. A little later when one could get a math coprocessor, king of the road. I started with Visicalc and Electric Pencil, a spread sheet and word processor what more could an engineer want. After the 286 machines got a little more RAM a few usable program began to emerge like Lotus 123 and Symphony, which I still use occasionally. I broke in on Me10 from HP in the drafting department. I helped get the first real package engineering programs at a time when we only had home built programs like an ASME Flange program and a few piping programs. The package programs for the engineering group were Compress, buggy and you had to hit enter or you were in DOS . Pipe Plus, we tried to run a gas manifold on a 286 the IT dept had taken the coprocessor out. 24 hours later we were still reducing the matrix. When it finally stopped we couldn’t display the results on screen. I had the first MathCad, It was a bear it didn’t handle units and any mistake kicked you out to DOS losing everything. Oh for the good old days.
We used a lot IMSA kits programed by wiring to do specific functions. There were still 4 in storage along with an original HP Signal Generator with a single digit serial number.

My first home computer was a Sinclair then several by Timex. Finally worked up to the TI 99-4A, first one was $999 and the last one was $49.99 as they got out of the business. They still work. Never did much work but had some nice games. It did teach you to write tight code. Later when I got a 286 Gateway, $2495 + 250 for coprocessor + $250 for 10 more megs of memory + $125 for 128K more ram. I soon bought and started using Pro Design for drawing and when they got BasiCad for programs and macros I could write some very tight code. I still use a lot of these programs to draw tubesheets, flanges, cabinets, bookcases and such. Still in DOS never switch them to VB.

 
Thanks Uncle!

You got started a little, but not much, earlier than me. The BIG difference is that you obviously started in an environment where computers were actually needed (even if you didn't get that impression first).

I started as a drive's designer with ASEA Västerås in 1963. That was slide rule territory. 100 percent. My first exposure to computers was an HP 1000 with TTY 33 (yes, 110 Baud and paper tape) and I think that it must have been around 1972. It swept me away. WOW! What a fantastic thing it was! We practiced algorithms and lean coding a lot. And execution speed. We had fun.

The first exposure to microprocessors was the intel 4004. We had two systems; the small system with 768 bytes of EPROM and the "big" system with 1280 bytes. Yes, bytes. What else?

Hand assembly and manual entering of HEX code into a ProLog programmer for 1708's. We still had fun. Then we got an MDS system. With 8 inch floppies that were real floppy. Error messages that just flew by on the screen so you could only read the last ones. Assembly could take an hour on that system. But no hand assembly any more - we thought it was great.

Then came the 8080, 8085, Z80, 6800, 6510 and the 6502. That is where I met FORTH. What a relief. How elegant. Work wasn't work any more (yes, pun intended) it was pure joy.

The early 8-bit micro computers (yes, I remember VisiCalc and The Electric Pencil - I even remember the ads with a guy hugging a pencil) had some quite good software. And booted in a split second. Have the Mega and Giga-everything devices really added value to life? Yes, perhaps. Downloading pdf would not work in those days. But sites like Eng-Tips would have been possible. BBS with nothing but ASCII worked quite well.

Oh, I think that I got carried away a bit. It was supposed to be about slide rules and calculators. But I think it was about eight-bitters mostly. Except for the 4004, which was a four-bitter. Cycle time was 10.8 microseconds and it took - I think - six such cycles to store an eight bit word in two consecutive memory locations. And we still did some quite good real time control with it. Not much checking or redundancy, though.

Let's hear about other members' experiences in these fields.

BTW, to get back on track: I received a Faber-Castell 8/10 circular slide disk calculator today. Just beautiful. Found one for about 25 USD. Not bad for such a beauty. MIB with instruction leaflet. Happy.

Gunnar Englund
 
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