ARM HP-12C devkit and cable? - Printable Version

ARM HP-12C devkit and cable? - Printable Version

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RE: ARM HP-12C devkit and cable? - Thomas Radtke - 08-05-2014 06:42 AM

(08-04-2014 07:16 PM)walter b Wrote: Certainly. Feel free to do it. It's just not my task to iron out HP's bugs IMHO. YMMV

I never expected you or the wp34s-team to do it!

As for myself, I'm sure such a task will be way over my head.

RE: ARM HP-12C devkit and cable? - Katie Wasserman - 08-05-2014 01:03 PM

(08-04-2014 08:39 AM)Thomas Radtke Wrote: BTW, does the 12C+ have a working brown-out detection?

I think that the answer to this is no, it works but not very well -- at least not in the latest firmware version that I have. I need to verify this but from what I remember it doens't give you much (if any) warning but does shut down before memory is lost. Somewhere out there in the forum archives is the answer to this. If you don't find it let me know and I'll do some more testing.

RE: ARM HP-12C devkit and cable? - Thomas Radtke - 08-05-2014 02:26 PM

(08-05-2014 01:03 PM)Katie Wasserman Wrote: Somewhere out there in the forum archives is the answer to this. If you don't find it let me know and I'll do some more testing.

Thanks, Katie, but I think that's enough to know. My hope was somehow to more or less replace the 12C firmware by that of the 15C and upload it to the 15C LE. Maybe it wouldn't be as trivial as that anyway.

RE: ARM HP-12C devkit and cable? - Marcus von Cube - 08-05-2014 03:43 PM

(08-04-2014 12:21 AM)Paul Dale Wrote: Curiosity or plans for a new re-purposing?

Starting with a 15LE for the scientific keyboard labels?

Not really a plan. Just curiosity what the differences to the 20b design are. Maybe I'll do something about it later (probably in the WP 31s direction).

RE: ARM HP-12C devkit and cable? - d b - 08-05-2014 04:14 PM

"Not really a plan. Just curiosity what the differences to the 20b design are. Maybe I'll do something about it later (probably in the WP 31s direction)."

Looks like I'll be buying a new 12c then.

RE: ARM HP-12C devkit and cable? - Jeff O. - 08-05-2014 06:33 PM

For the sake of the following discussion, I will refer to the current 12C platform which emulates the original 12C rom on an ARM-based platform as the 12C+. To the best of my knowledge, this hardware is identical to the 15C LE hardware.

(08-05-2014 02:26 PM)Thomas Radtke Wrote: My hope was somehow to more or less replace the 12C firmware by that of the 15C and upload it to the 15C LE. Maybe it wouldn't be as trivial as that anyway.

I’m not sure if I understand your hope. Did you hope to somehow cut the 15C rom portion out of the 15C LE firmware, cut the 12C rom portion out of the 12C+ firmware, then insert the 15C rom into the hole in the 12C+ firmware so that its emulation layer would then run the 15C code? That sounds like an interesting idea. If one had access to the actual firmware files, one could inspect them with a HEX editor, but I don’t see how it would be possible to tell where the emulation code stopped and the original rom code started in either file. But then again, I don’t know much about such things (as is probably quite obvious to those who do), so maybe it would be possible.

Still, it sounds like our best bet for a bug-free implementation of the 15C functionality on 12C+/15C LE platform would be for a clever person to wrap the original 15C rom code in a newly developed emulation layer to run on the 12C+ and 15C LE platform. I'm sure that clever person could most probably provide functioning brownout detection while her or she was at it. Unfortunately, such a clever person would run the risk of making HP's lawyers angry, so it is probably not a reasonable thing to ask someone to do. (I believe Forum member “uhmgawa” pursued getting HP’s permission to use the original code in such a manner, but could not get past their legal ramparts.) As an alternative, a clever person or a clever team of people could almost certainly develop firmware for the 12C+/15C LE platform which would simulate the 15C in all respects (and provide some functioning brownout detection, of course, plus any appropriate augmentations to the original capabilities) without actually using any code owned by HP. That would of course be a lot of work and again may be a lot to ask.

RE: ARM HP-12C devkit and cable? - Thomas Radtke - 08-05-2014 07:10 PM

(08-05-2014 06:33 PM)Jeff O. Wrote: I’m not sure if I understand your hope. Did you hope to somehow cut the 15C rom portion out of the 15C LE firmware, cut the 12C rom portion out of the 12C+ firmware, then insert the 15C rom into the hole in the 12C+ firmware so that its emulation layer would then run the 15C code?

Not exactly. I do have the 15C ROM image. Since we got the emulator sources, it shouldn't be impossible for some clever people to figure out how to replace the 12C firmware.