Yes thanks jfb9301, that was one of the first places I looked, and I did take the convert programme and try it in a Free42 emulator; it does the trick in terms of common unit conversions.
Or are you looking more for constants like speed of light, gravitational constant, and Avogadro's number?
Walter is right, now that I've found a unit convert programme, physical constants like those listed above and things like permittivity and permeability of free space etc, plank's constant etc. etc. would be really useful.
I've looked in the 42S programming help manual and there is a good example of how to use in-programme menus, so I could adapt that to be able to select and load different physical constants in the X register, but if someone has something already written that would be even better....
Unless you need something elegant, why not just create a dead simple program to put all your favorite constants into the X register when you call by name, something like:
Walter is right, now that I've found a unit convert programme, physical constants like those listed above and things like permittivity and permeability of free space etc, plank's constant etc. etc. would be really useful.
It's based on the constants embedded in the HP-35S.
Connect your DM42 to your computer with a standard microUSB cable then SETUP > File > Activate USB Disk
This connects the DM42 as if it were a small, 6MB memory stick. You will see a directory called "PROGRAMS" in there. Copy the const.raw file downloaded earlier into this PROGRAMS directory.
Now "eject" the DM42 as you would a memory stick. Depending on your computer and how you eject the DM42, you might have to press [EXIT] a couple of times to get back to the SETUP > File menu.
Now go into "Load program". Scroll down until const.raw is selected and press ENTER.
Exit the SETUP. From now on, all you have to do is XEQ "CONST" and you have a library of constants at your disposal.
There are only 10 kinds of people in the world: those who understand binary and those who do not.
This is not perfect but might get you started. I wrote a short constants program the other week for Free42, in preparation for receiving my DM42. I removed many of the constants I don't need access to, but the general idea of how to build a multi screen menu that returns constants is demonstrated. My program has 18 constants split across three menus. I pulled value from NIST.
If anyone has a better way of doing this, I'd love to know. I do think it would be great if the DM42 had a list of constants built in. I suspect you could come up with a more elegant interface if done at a lower level in the firmware than as a program.
Here's my version of the beginning of a constant library, with the added bonus of showing the unit as well. It's been a while since I coded this, so maybe I've already posted it somewhere. (BTW, unit algebra is something I miss after using it extensively on the HP48).
This clearly is a very supportive community. Thanks for all the replies regarding a physical constants programme. I've been busy for several days and not had chance to check into the forum.....and now when I do, I find a number of people have posted with code examples etc. That people would bother to help in this way really made me smile.
My DM42 arrived today (UK); after a quick check (seems like a great machine), it's been put away for Christmas. If I'm a good boy and I get the DM42 on Christmas day, I will pursue the physical constants programme then. The code that various people have provided will clearly give me a head start, if not a complete solution (I've only skim read the replies before posting this thank you)....
Walter is right, now that I've found a unit convert programme, physical constants like those listed above and things like permittivity and permeability of free space etc, plank's constant etc. etc. would be really useful.