A bug of the HP-15C Collector's Edition running in HP-16C mode?

[fvogel]

Just discovered what seems to be a bug of the HP-15C Collector's Edition running in HP-16C NOMAS mode. Steps:

1. Enter the 16C hidden mode (From the OFF state, push g and ENTER and then ON ; hit 4 and then 7)

2. Hit a key to erase the "Pr Error" message. Then hit, say, 8

3. Hit f and SHOW BIN (for instance, or OCT, or ...) to display the current value in BIN temporarily.

4. Before the end of the temporary display, hit a key, say 2

-> The calculator is totally frozen

Only the reset button (or battery removal) brings it back in a working state.

Anyone else seeing this? Any fix available perhaps?

Thanks!

[rprosperi]

Thanks for reporting this.

It is known that the 15c CE's NOMAS 16C mode [f]+[BASE] display modes are not correct (the display should stay on as long as you hold down the [BASE] key) and this behavior you're reporting is really a side-effect of that core problem, but detailing it this way is useful to let folks know to not press another key so quickly and thus avoid having to reset. So, thanks!

[Valentin Albillo]

.
Hi,

This post (#3 in the thread) by brouhaha mentions the probable cause of most (if not all) display problems.

Seems to be a hardware problem so perhaps not fixable by firmware updates ?

V.

[Voldemar]

Let's try this:
Default mode (or 15.2 mode)
Press [f]
Press and hold [<-] PREFIX
Press any digit key

[brouhaha]

(03-09-2024 04:00 PM)Valentin Albillo Wrote:  Seems to be a hardware problem so perhaps not fixable by firmware updates ?

Hi V.!

I'm reasonably sure that it's a problem with the SIMULATED hardware, not the physical hardware, so it should be correctable in the simulation code that's running on the ARM core. Alas, since I don't have access to the source code of the simulator running on the ARM, and don't want to spend a lot of time reverse-engineering it, I don't know exactly how it's going off the rails nor how to fix it.

In the past Cyrille has solved similar problems in the 12C and and 15C, and I've occasionally been able to offer him a little advice, but it remains unclear as to whether there will ever be a firmware update for the 15C CE that might include fixes to the undocumented and unsupported 16C mode.

[fvogel]

(03-09-2024 09:57 PM)Voldemar Wrote:  Let's try this:
Default mode (or 15.2 mode)
Press [f]
Press and hold [<-] PREFIX
Press any digit key

--> The display showing the digit that got hit during the last step flashes. This looks indeed like another display bug.

At least it has no adverse impact because hitting another key restores normal working.