Back to the math stuff:

I finished my engineering degree with a math minor; I only needed something like 6 more credits to have a double degree in ME and mathematics but was sick of school (and out of money).

I think technically that the majority of trig is planar or constrained to a planar slice of 3D space (unless you're getting into spherical geometry or other non-Euclidian stuff). Algebra plays well in 3 (or more dimensions). I remember calculating some FEA problems by hand where the matrices were ~50 x 50 (which I guess is nothing compared to "real" FEA problems calc'd by software where the matrices are 1000's of elements wide...).

Hardware:

A Keufell & Esser slide rule (plastic) and a laminated aluminum Picket with the extra scales - both with belt holsters of course.

http://forums.pelicanparts.com/uploa...1603341484.jpg

http://forums.pelicanparts.com/uploa...1603341484.jpg

Another Picket with its book and box (no idea where this came from):

http://forums.pelicanparts.com/uploa...1603341484.jpg

Another K&E - laminated wood (looks to be walnut which was unusual):

http://forums.pelicanparts.com/uploa...1603341888.jpg

Guess the photo didn't come out that well.

Hodge-podge of "old" stuff. Bonus points if anybody else has the same mouse pad (and an old SGI 550 workstation in the garage to go with it).

http://forums.pelicanparts.com/uploa...1603342038.jpg

Not quite sure where the drafting instruments came from; it's older stuff and one of the dividers is engraved as 1940. The dead reckoning calculator was used by my wife's grandfather (who wasn't a pilot but was an engineer involved with aerospace in the 50's). This set of drafting instruments was given to me by one of my college profs as a graduation present; not quite sure on the date.

http://forums.pelicanparts.com/uploa...1603342038.jpg

I have actually used this set many times. The ruling pens work almost as well as my old Rotring tech pens - just don't move your hand too quickly.

Was looking in my chest of drafting equipment for the old fountain pens and Rapidograph mechanical pencils - can't find them. Not sure where my lead holders are either.

(And the secret to keeping the lead in your lead holder sharp is to rotate the lead holder while pulling a line...)

Audell's is a great book to go through. My copy is very old, pages yellowed, and it's falling apart - I'm almost afraid to open it.

And I guess I'll just put these links here (just in case you've read everything at the Museum of HP Calculators website):

https://sliderulemuseum.com/SRM_Home.htm

https://www.sphere.bc.ca/test/ke-sliderule.html

https://www.sphere.bc.ca/test/pickett.html

One piece of calculation hardware that has always fascinated me is the mechanical integrator. I've seen one once in person - fascinating mechanism:

https://commons.wikimedia.org/wiki/File:Mechanical_integrator_CHM.agr.jpg

http://forums.pelicanparts.com/uploa...1606162596.jpg

I'm pretty excited - bought a HP92 on the 'Bay and excitedly awaiting its arrival.

The HP92 was Hewlett-Packard's desktop "financial/investor" printing calculator. https://www.hpmuseum.org/hp92.htm It is much rarer than the HP97 desktop "scientific" printing calculator, which I have sitting on my desk. I have been looking for a HP92 for many years, but they all seem to be $600+. I finally found one for a reasonable price and grabbed it. It has a problem in the paper feed mechanism, but I took the gamble that I can fix that.

Why do I care if it is a HP92 or a HP97? Why do I want either on my desk? Well, sometimes you need to do some quick calculations and don't want to fire up Excel, I have a hard time using an algebraic calculator, and I really have little need for scientific functions but do occasionally have need for TVM and IRR functions. I think the HP92 does bond math too but I doubt I'll use it for that.

Very cool, congrats on the find/purchase!

My Dad used to guard this during the Korean War. He was 3/4th the way through college (Aeronautical Engineering) when he was drafted. His choice: OCS or Technician at the Supersonic Wind tunnel at Aberdeen Proving grounds, MD.

So, yep, he regularly pulled guard duty on the ENIAC.

http://forums.pelicanparts.com/uploa...1606163888.png

I believe Boolean logic was the programming basis????

http://forums.pelicanparts.com/uploa...1606888597.jpg

Here’s the HP92 elbowing aside the HP97. It needs the printer rollers repaired but that seems doable. HP97 is going on the shelf.

http://forums.pelicanparts.com/uploa...1606888947.jpg

But is the fountain pen a Pelikan?

I grew up in the TI-82 era so no slide rule for me, but still have an old CRC kicking around:

https://i.ebayimg.com/images/g/am8AA...L7/s-l1600.jpg

I haven't been able to locate my dad's stuff from his time in the Navy but I'm still looking. Just need to dig a bit deeper.

I'm a Francophile, so its a Waterman :-)

Out of the blue, my brother offered me my father's slide rule yesterday. He's doing some housecleaning. I will post a picture when I get it. He graduated from engineering 71 years ago...:eek:

and differential equations? i got a B in that class, and i still never understood it. i just followed the steps.

Very cool!

http://forums.pelicanparts.com/uploa...1606931458.jpg
http://forums.pelicanparts.com/uploa...1606931458.jpg
http://forums.pelicanparts.com/uploa...1606931458.jpg

Wow I haven't thumbed through a CRC in years. I still have my Lange's handbook but I loaned my Merck index to a friend and never saw it again.

Really early stuff...
 

hahahaha.