HP 12C ATSAM4L version: ON-f-ENTER - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html) +--- Forum: General Forum (/forum-4.html) +--- Thread: HP 12C ATSAM4L version: ON-f-ENTER (/thread-19620.html) |
HP 12C ATSAM4L version: ON-f-ENTER - brouhaha - 03-06-2023 08:07 AM I was trying to remember the key sequence to get the firmware version of ARM-based HP 12C calculators (which starts with ON-g-ENTER), and before I hit upon the right combination, I tried ON-f-ENTER. After doing that, the 12C behaved normally, except that it would not turn off. The ON key after that was completely ignored, until I reset the calculator. Has anyone else noticed this? I've only tried this on a recent ATSAM4LC2C based 12C, not the earlier ATSAM7L128 version. It seems to be reproducible. I imagine it's intended as some kind of factory or R&D test mode. Some might find it amusing that I discovered this by accident when poking keys with my fingers, and not by spelunking through the firmware. RE: HP 12C ATSAM4L version: ON-f-ENTER - Mark H. Shin - 03-06-2023 01:37 PM (03-06-2023 08:07 AM)brouhaha Wrote: Has anyone else noticed this? Confirmed. For both Philippines (S/N PHA...; ChE -- d1d1h; 2015-01-30) and China (S/N C1G...; ChE -- 0F0Fh; 2015-01-08) production, calculator cannot be turned off without reset. RE: HP 12C ATSAM4L version: ON-f-ENTER - rprosperi - 03-06-2023 03:38 PM This was found and reported by (of course) Joe Horn last year. Note that it also disables the auto-power-off feature after some number of minutes. To re-enable the ON key, press and hold f+ENTER then press ON. There's no info if this was done on purpose (e.g. for diags or battery life testing, etc.) or if it was a simple bug. The fact that the mode can be both enabled and disabled suggests it was there for some purpose, but there were other deleterious side-effects noted (some functions performed more slowly) so probably best to NOT use this "feature". RE: HP 12C ATSAM4L version: ON-f-ENTER - Mark H. Shin - 03-06-2023 04:31 PM (03-06-2023 03:38 PM)rprosperi Wrote: probably best to NOT use this "feature". Another thing I noticed, running the iteration test program, while operating in this "feature" mode, the "running" displays continuously... RE: HP 12C ATSAM4L version: ON-f-ENTER - brouhaha - 03-06-2023 06:27 PM (03-06-2023 03:38 PM)rprosperi Wrote: This was found and reported by (of course) Joe Horn last year. I'm not at all surprised. Quote:Note that it also disables the auto-power-off feature after some number of minutes. I suspected that it might. I didn't leave it on to find out, because I thought it might also have increased power consumption compared to normal mode, though I haven't tried to determine whether that is the case. Quote:To re-enable the ON key, press and hold f+ENTER then press ON. That seems to behave in an inconsistent manner on my unit. I've seen: 1) does nothing, calculator still in forced-on mode 2) calculator turns off, and at the next power-on, gets "Pr Error" (memory lost) 3) calculator turns off, then calculator won't turn on for a while, or perhaps some number of repeated attempts 4) calculator turns off, then ON key turns it on normally I assume that #4 is the intended behavior, but in my experience that's the least common outcome. Quote:There's no info if this was done on purpose (e.g. for diags or battery life testing, etc.) or if it was a simple bug. It seems highly unlike that it's a just a bug. Quote:The fact that the mode can be both enabled and disabled suggests it was there for some purpose, but there were other deleterious side-effects noted (some functions performed more slowly) Interesting! I didn't poke at it enough to discover that. Quote:so probably best to NOT use this "feature". Agreed. It's clearly not intended for users. |