using hp11c to travers and inverse

i haven't surveyed in several decades,  but was recently asked if i could lay out a railroad curve.  in my enthusiasm i said yes.  however,  when i looked at my old calculator my mind went blank on how to use it.   i know the math to use,  just not the calculator key steps

can someone tell me how to inverse and traverse with an   hp 11c

From what I can see the 11C is powerful enough to do much of what you want and even be programmed to do so.  There are libraries of programs and solutions books for many similar calculators from the HP-34C the HP-65 and 67, HP-25 and so forth that have the ABCDE keys. 

Since you know the math, you may need to lean the calculator, how to use RPN and some simple programming should follow along. Usually all these calculators came with a good instruction manual that will contain essentially a tutorial on problem solviing using the calculator manually.  Then existing programs can serve as a learning tool, or be adapted to the 11c, specifically for the traverse and inverse functions.  Much can be accomplished from the keyboard with the basic trig functions, pi, and a page of curve formula's.  Traversing and inversing can also be done without a program by mastering the polar to rectangular functions and judicious use of a few storage registers.

Email me if you need help getting started.

- jerry

Look on the back of the calculator for diagrams of polar to rectangular conversions. I have a 15C that has the diagrams and I think that the 11C has the same functions.

You would probably need to find an instruction book to figure out the programing but quick P>R and R>P calculations can be made without programs.

T.W.

P.S. Don't forget Railroad - cord definition

Trvaersing and inversing requires a rather large body of coordinates. The HP 11 has only a 4 deep stack, and 10 storage registers, each register holding one value. At the most one could store 5 coordinate pairs. The HP 11 can be programmed to calculate incremental Northings and Eastings from angles and distances but I doubt it is worth it. A simple flow chart in front of you and you could probably key in every step. If I were to attempt to store coordinate pairs I would use 5 point numbers, putting Northings in storage registers 1-5 and Eastings in 6-0. It takes 5 points to traverse around a 4 sided lot.

An HP 11 is a calculator not a data collector, but it is a very good calculator. I use my 2 every day all day, one key at a time. The only stored values in registers all the time are US Survey Feet per meter and Square Feet per acre.

Paul in PA

Paul- the 11c also has a program memory. There is a solutions book out there somewhere that has the program steps. There are also books called "An Easy Course in Programming the 11c". The last time I had an 11c was in 1986, so I don't have those books. But the 11c works almost exactly the same as any HP of the genre. Any Solutions package should give you the steps, and any HP Manual should show the keys and functions. The program utilizes the storage registers and the stack. But you need to make sure you use the railroad curve solutions formulae. The 41C solutions book contains all of the formulae used for the solutions. You can work through them by hand and save the steps. Rust never sleeps. You have to practice.
MLB

Yes it has memory to store a program, but does it have storage memory that is addressable from a running program?

I never thought it worthwhile to write an HP 11 program. I bought my first HP 11 as a companion to the HP 41 where I did all my programming. I also bought the HP 41 Survey Module and a printer and soon added extra memory. One of the other engineers in the office had a card reader so we exchanged a lot of programs. I was writing stormwater runoff programs. We had 4 working engineers with 4 HP 41s with survey modules. I believe the survey techs and one survey draftsman had HP 41s with the Tom's ROM. It allowed storage of more coordinate points that were also more easily addressable.

Paul in PA

You can download a virtual 12c here. Couldn't find the 11c.
You can also get the virtual 41. I have that on my desktop.
MLB
http://www.brothersoft.com/downloads/virtual-hp-12c-calculator.html

I was testing the Virtual 41 I have on my desktop with some programming from the old Solution books I dug out. It works fine. The Circular Curve sequence works fine. I would have to do Railroad Curves from the formulae. But the keyboard of the 41 has just about the same layout as the 11C. I don't have time to scan the hard copy for posting right now. But maybe in the future if this can't be resolved otherwise.
MLB

thanks for ll the input folks.  i've figured out how to do basic traversing and inversing now. and once i started doing some practice problems,  my fingers started remembering.  i don't think it will be long before i'm back to "good enough" speed.  at least for what i'm doing.  i have zero desire for any programming,  because thats how several surveyors i've asked didn't know/ remmember how to.....just like me,  but i havent done it in a very long time is my excuse.  i'm sure i can get my old books out and relearn how to run a railroad cureve,  and do some bearing beariing interasections for some folks also  OK,  once again thanks a bunch and hope all have a great turkey day-----texas bob