Just bought a new old stock HP-12C Gold

[lvt]

So after almost a year of using the HP-12C Platinum, I decided to add a gold version of the 12C.

I'm not sure if other 12C users would agree, but I found that the old 12C has better screen with bolder numbers and better keypads (it's softer so I don't have to use force to press).

I don't know what the 6-pin connector is for though.

[lvt]

[lvt]

[HP-12C]

I've noticed the keyboard as well with the newest 12C's, they do seem to require a more firm press compared to the older versions.

The connector is intended for flashing the 12C with different firmware, operating system.
HP did publish a software development kit, I don't think this is online anymore though.

[lvt]

(10-30-2023 05:22 AM)HP-12C Wrote:  I've noticed the keyboard as well with the newest 12C's, they do seem to require a more firm press compared to the older versions.

Thanks for confirming, so it's a fact though.

(10-30-2023 05:22 AM)HP-12C Wrote:  The connector is intended for flashing the 12C with different firmware, operating system.
HP did publish a software development kit, I don't think this is online anymore though.

What do you mean by "different firmware, operating system"?

I'm familiar with rooting/flashing smartphones, maybe I would give my 12C a try.

[HP-12C]

I'm not a computer programmer but this may help:

https://www.hpmuseum.org/forum/archive/i...-5171.html

[lvt]

(10-30-2023 06:04 AM)HP-12C Wrote:  I'm not a computer programmer but this may help:

https://www.hpmuseum.org/forum/archive/i...-5171.html

Thank you.

[lvt]

BTW, is it normal that I can change screen contrast on my 2015 12C?

From what I've read it's only possible on the newer 12CP.

[Eric Rechlin]

(10-30-2023 06:04 AM)HP-12C Wrote:  I'm not a computer programmer but this may help:

https://www.hpmuseum.org/forum/archive/i...-5171.html

Unfortunately the published SDK for the 12c only seems to be for the older AT91SAM7L128-based model, not the 2015+ model based on the ATSAM4LC2CA. The differences are probably fairly minimal, though, but I haven't looked into it to verify.

The programming cables are a bit different, though; the cable for the ATSAM4LC2CA is actually a bit simpler, since it speaks USB instead of TTL serial and doesn't need the level shifting chip.

[Jlouis]

(10-30-2023 04:55 PM)Eric Rechlin Wrote:  

(10-30-2023 06:04 AM)HP-12C Wrote:  I'm not a computer programmer but this may help:

https://www.hpmuseum.org/forum/archive/i...-5171.html

Unfortunately the published SDK for the 12c only seems to be for the older AT91SAM7L128-based model, not the 2015+ model based on the ATSAM4LC2CA. The differences are probably fairly minimal, though, but I haven't looked into it to verify.

The programming cables are a bit different, though; the cable for the ATSAM4LC2CA is actually a bit simpler, since it speaks USB instead of TTL serial and doesn't need the level shifting chip.

Eric, it is so possible to flash the 15c firmware into these 12c?

[Eric Rechlin]

(10-30-2023 05:37 PM)Jlouis Wrote:  Eric, it is so possible to flash the 15c firmware into these 12c?

The 15c LE firmware can be flashed on the pre-2015 ARM-based 12c calculators. The 15c CE firmware can be flashed on the post-2015 ARM-based 12c calculators.

[lvt]

(10-30-2023 05:55 PM)Eric Rechlin Wrote:  

(10-30-2023 05:37 PM)Jlouis Wrote:  Eric, it is so possible to flash the 15c firmware into these 12c?

The 15c LE firmware can be flashed on the pre-2015 ARM-based 12c calculators. The 15c CE firmware can be flashed on the post-2015 ARM-based 12c calculators.

Hmm, now I see why my 12C's screen is identical to the 15C's screen, segment by segment.

I was wondering why there are USER and GRAD signs on the screen while there is no related function.

[lvt]

I guess that the same screen has been used for more than one calculator?

And if we flashed the 12C with 15C firmware, how about the keypad?

[Massimo Gnerucci]

I believe some news are approaching.