The Rogue HP-12c

[dm319]

(09-13-2024 12:16 PM)AnnoyedOne Wrote:  That is my theory based on the 12CP-like checksum in your Brazillian 12C. I've no proof of that though. Having the firmware image would prove/disprove it with the presence/absence of NUT firmware.

I'm sure you are right - after seeing results with 16
digits, there is no way NUT emulation is going to return
that.

(09-13-2024 12:16 PM)AnnoyedOne Wrote:  I was referring to the "comma" issue not any TVM results. Those are of little interest to me. To you yes. And others maybe. The same with effective digits of precision.

Ok fair enough. The bug is the least interesting bit for
me, though it was the initial thing that caught my attention
about the calculator.

I don't know why you don't find the TVM results interesting.
If this was just the bug it would be a mild curiosity. The
TVM results are what tells us that the firmware is entirely
re-written.

PS confirmed bug is present on this device

(09-13-2024 12:16 PM)AnnoyedOne Wrote:  I think the WP34S calculator project has some 34 digits of precision. Fine if you're an astro-physicist wanting to calculate the circumference of the universe to the nearest millimeter. For me (and most engineers in general) 4-6 digits is plenty. For boundary TVM (and some other) calculations the more the better.

That's really not my interest in the digit precision - this
tells me this isn't NUT and it isn't Saturn either. This is
completely re-written.

(09-13-2024 12:16 PM)AnnoyedOne Wrote:  That suggests that the 12CP x^2 functionalty was removed or was never present in your 12C. It doesn't disprove my 12CP firmware adaption theory but it doesn't support it either.

I don't think this is anything to do with the HP-12cp
firmware - not only does the TVM not behave like it, but
returning 16 digits would not fit with that either.

(09-13-2024 12:16 PM)AnnoyedOne Wrote:  Perhaps HP back-ported code from newer (Saturn) models to the 12C and it "got out into the wild" before testing was complete. Maybe they have the same checksum code. Or Brazillians were unwitting "beta testers".

I do like the idea of this, but they would probably have
used the Saturn C libraries. I wonder if they were planning
a new native calculating platform that had 16 digit
precision? It probably would have worked out fine if it
wasn't for the TVM solver.

(09-13-2024 12:16 PM)AnnoyedOne Wrote:  From off, hold g and ENTER, then press ON. The display shows 1.L 2.C 3.h or 1.L 2.C 3.h 4.CPu in later 12CP's. Pressing 2 (2.C) should show the firmware information. I believe that 12CP'S have a brief delay (while calculating the checksum?) before showing

Thanks, got this:

Code:


1.L2.C3.H4.Cpu
ChE--564Ah
Ver 02
C 2004 hP

(09-13-2024 03:01 PM)AnnoyedOne Wrote:  You probably already know this but you're the only one in these forums (to my knowledge) that has a "Rogue 12C".

I feel very special. There has already been a fair
significant cost, so maybe with my next pay check... Of
course if anyone in the UK fancies lending it to me, and I
can send it back. My main worry is damaging the device.

(09-13-2024 03:01 PM)AnnoyedOne Wrote:  That said I suspect that some here are willing to spend some time to do some examination/testing of the firmware if you do this. Just keep the image private and share by request (e.g. email) only. It is not yours to make public. You don't want to receive any letters from any HP/Moravia lawyers

Yes, have been avoiding using my yacht this week anyway...

Can I canvas some help - I'm suspicious this probably isn't
BCD - can anyone help me prove it? I believe some modern
Casios are binary underneath, but with enough hidden digits
this is very difficult to prove.