Old programmable calculators


Staff member
In the 80's and 90's programmable calculators were used on all the expeditions I went on.  You imputed the length, bearing and clino readings and you got out easting, northing and elevation (XYZ) co-ordinates.  These were then plotted out on graph paper and formed the basis of the finished survey.  Things have moved on a bit since then, but I used to enjoy that method of surveying and drawing up.

Anyway, I came across two old survey calculators from that era in the bottom of a draw.  I imagine they would work if the battery was changed.  Anyone have a use for them before I throw them out.



Active member
Definitely don't throw them out. There are a surprising number of middle aged geeks reminiscing about the old days, and having enough disposable income to buy old shit from the bottom of peoples drawers.



I sold a spare 30 year-old HP42s with manuals a few months ago for ?200. I was surprised how much of a cult this stuff is. We had a stack of them in the stationary cupboard at work, I only had one and a spare?.

I would run it through Ebay before binning them. See if they come on. Admittedly they look like you took them caving.


Active member
In the 80s and 90s I got no further than the "hilarious" typing 58008 and then turning them upside down, so glad to hear people were getting better use out of them than me


Well-known member
There's young geeks as well  like vintage calculators - one of my teammates likes fixing them up, and he's in his twenties! As suggested above, I'd try putting new batteries in them and see if they fire up. Even if you don't, you could try them on Ebay and if them don't sell, ping me and I'll see if my work colleague is interested.


Active member
I still use my vintage HP11C. It's sits on my desk and is much handier than Excel or finding the calculator on my phone. I bought it some time during the 70s. At that time a huge advantage was it was Reverse Polish, which meant people didn't borrow it, or if they did, they handed it back immediately with a shudder. (RP means no brackets, so no need to think ahead).



RP means never losing a calculation halfway through. It?s even better being able to see two lines like on the HP42.

There is a fab app called Free42 which fully implements the functionality of the HP42 so you can use the solver etc. My real one thinks for a few seconds when doing a convergence, the iPhone is instant.

If you want to see how serious the guy is about this app, check out the extended instruction set. It?s a life?s work. You can query the GPS and accelerometer, so maybe that?s interesting.