HP 12C+ Firmware

[Stevetuc]

(08-24-2023 01:40 AM)dvcirilo Wrote:  Thanks, I have tried this one, but it does not work, doesn't even turn on.

The HP12C+_12-12-2011 version kindly posted by Katie here, which gives me the weird behavior, minus sign always on, "f" and "g" keys not working, etc. Basic operations work ok.

I'm looking for either the 2009-11-19 or 2009-07-24 versions, as cited here.

Originally this 12C had the 2008-06-28 version.

I reverted back to the 15C firmware. Maybe its fate now is to live as 15C forever.
I'm better looking for a keyboard overlay.

Perhaps try this rom
HP-12C+_Jose.bin
Jose from Calculatorstore sent me this as the latest rom for the older HP12C+
He mentions here New flashing service that he successfully flashed this onto the HP12C+ older version (pre 2015)

I have checked the file with a hex editor and the original firmware is embedded in 16bit bigendian at hex offsets 5034-8F31.
The files you had trouble with I am unable to find the original firmware embedded within which may (or may not ) explain the problems you had.

I'll post a bit more later regarding finding the embedded firmwares within both the HP12C+ and HP15C+ (LE) firmwares that are available via other posts on this forum.