Let us know how it is!

http://forums.pelicanparts.com/uploa...1602959991.jpg

I went looking for my HP41CX and found it along with some books. None of this has seen the light of day in many many years. The books are long out of print. I should scan them and then sell the physical books to collectors.

The batteries are dead. Need to fix that.

I compared the keyfeel. The HP key travel is longer and smoother, and the tactile click is "softer". The DM key has a crisper tactile click and a shorter travel, and also a more audible "click". It also may require slightly more force, at least in its brand new state. After doing the comparison, I no longer feel the DM keyfeel to be inferior to the HP keyfeel. It's just different. One is a GT 928, the other is a track 911. I do think the HP keys are more attractive, with their trapezoidal shape and multi color printing. That is pretty clear.

Hopefully the gold battery contacts in your 41 survived the old N cell batteries. Those were the one thing I really miss not having a Radio Shack anymore.

Gold ?
Whoa, gotta dig mine out to check it out.

The batteries didn't leak, contacts look good. Whew! Any rec for replacement batteries?

I have some Energizer E90 alkaline batteries for my 41CX - seems to work OK.

I do take the batteries out if letting it sit for a while.

Your description of the key differences between the DM42 and the 41CX is pretty spot on to how I would characterize the differences between the HP 42s and the 41CX. Maybe the DM42 replicates the 42s keys best they could. You may have just talked me into buying one...

They also have a DM41 that is supposed to be to the HP41C/CV/CX as the DM42 is to the HP42S.

I looked at the DM41 and it's a cool piece of hardware. I'm "backward" though and started with a 42s and so will be chasing that instead. I got the 41CX as a "I'm cleaning out the garage and don't know what this is anymore" gift from my neighbor years ago. I remember trying them both years ago when "comparison shopping" and the 42s made more sense to me.

Side note - I've got a bunch of slide rules and antique drafting instruments around too - was thinking about starting a thread on that but am guessing that will have near-zero appeal to anybody but us math/engineering geeks. Maybe somebody would bring out photos of their old Curta... (one piece of mechanical elegance I've yet to see in person...).

I've got an old Pickett slide rule a lot like the pic below that my dad brought home from work for me when I was ~13-14. They were anachronistic by then. I also have several old Japanese abaci.

I'd love a round slide rule. I need to spring for one some day.

https://ralphlosey.files.wordpress.c...slide-rule.jpg

If you start a thread, they will come.

I gave my son my old K&E slide rule, he actually uses it, a little. He's fascinated by it - log math is pretty darn cool.

He's a second year architecture student. I'm trying to push him to get a business degree or at least a business minor, take all the real estate development and management classes available, intern for a developer, telling him he'll be a better architect if he understands how the business side works. He's generally agreed to that, is taking economics classes to start out. Naturally I've given him one of my HP12Cs.

His structures class assignment last week was to build a bridge from wood coffee stirrer sticks (the disposable ones that you buy from restaurant supply stores), then the professor took all the students' bridges and tested them to failure by placing on a jig then loading with a bucket into which he poured sand until the structure collapsed. My son really took it seriously, came home to use our basement art studio, stayed up all night, glue-laminated sticks into cross beams and built a well-braced structure, left at 4 am to drive back to Eugene with his wood stick "bridge". The professor was not able to collapse it, despite adding a second and then a third bucket of sand. The video of the testing is funny. Prof is hunting for more buckets and more sand, finally gives up and calls it a pass!

I had a circular slide rule in high school, loved it.

Start the thread! What do you have to lose beside your $ as you start buying archaic computing machines?

Hell I spent $600 buying Monroe Bond Calculators on eBay until I finally got control of myself.

OK - Thread started:

http://forums.pelicanparts.com/off-topic-discussions/1076054-old-engineering-mathmatics-stuff.html#post11069395

I don't need to spend more money - I already have a collection of this stuff (gathered over the last 35 years or so)...