How to you compute Trig functions in radians on the HP71B?

[rprosperi]

(08-22-2018 02:15 PM)KeithB Wrote:  I *love* the HP71B calculator mode. I wish the Prime was similar with pre-calculation of results. The 71 is my main calculator at work since they frown on calculators with lots of memory and wireless communications in a secure area.

Unless you really like Algebraic use (there is no accounting for taste, even here) I can help with that. There is a great RPN program for the 71B, written by Chris Capaner in '84/85 which lets you use the 71B just like any other HP RPN calculator, but still retaining the 71B's powerful and flexible BASIC. It is a BIN program, so it's instantaneous (unlike some BASIC RPN programs) and it retains the stack values when you exit (to use BASIC) and then return to RPN. It also provides (via a tiny LEX file) commands to access the X, Y, Z, and T stack values from BASIC, so it can also be easily integrated into some larger shell program if desired. This program can be found among the OLDP disks, in files RPN (Type BIN, 1288 bytes) and RPNLEX (Type LEX, 172 bytes).

It did come with an overlay (there are about 50 functions), but you can easily make one using one of the blank 71B overlays that you see on eBay, etc. still relatively cheaply. I have scanned my original and will find a link to the hi-res image posted here in the past.

There is also another more ambitious 71B RPN program, providing most of the functions of the Voyager models (without programming, but after all, you have BASIC underneath) which I will post info on soon, just trying to find a bit more documentation.

So even die-hard 71B users can still enjoy the comfort of RPN.