HP-15C CE 15.2 mode -> 15 mode Caution

[Benoit Maag]

If this was mentioned in a previous post, please accept my apology.

I just updated my HP-15C CE to the new software with checksum 0A0Ah and tried the 15.2 mode with more memory registers. Works great but some caution is needed when going back to the normal 15 mode.

If the number of memory registers is set at 98 or 99, then the memory is corrupt when you go back to normal 15 mode. g-MEM gives you an Error 10, and so does g P/R to go to program mode. No sweat and no need to open the battery door and hit reset - going back to 15.2 mode, setting the number of memory register back to 97 or less will allow you to go back to the normal 15 mode w/o error.

[J-F Garnier]

This is quite understandable since the "15c mode" has 96 allocatable registers only so 98 registers including the non-allocatable R0 and R1.

Actually, for safely returning from the 15.2 mode back to 15 mode, the rule is that there must be at least 96 free allocatable registers, whatever the registers are used for storage, matrices or programs.

But frankly, why switching back to the 15c 96-register mode ?

J-F

[RPNerd]

(08-15-2024 07:28 AM)J-F Garnier Wrote:  But frankly, why switching back to the 15c 96-register mode ?

Because I'd be wary of using something that's NOMAS when I want something reliable!

[AnnoyedOne]

(08-15-2024 08:55 AM)RPNerd Wrote:  Because I'd be wary of using something that's NOMAS when I want something reliable!

As far as I know 15.2 mode doesn't have any issues. I leave mine in 15.2.

A1