HP25c continous memory

[Dave Britten]

(02-16-2021 12:12 PM)Steve Simpkin Wrote:  The HP-25C included an additional 16 page pamphlet called Getting The Most From Continuous Memory that explained what was saved in Continuous Memory and how to best use it. The following was saved when the HP-25C was turned off: all 49 program steps in program memory, all 8 data storage registers and the Last X register. As you know, the stack was not preserved.
Here is a copy of the pamphlet.
https://literature.hpcalc.org/community/hp25c-cm-en.pdf

Interesting, apparently I hadn't read that in very close detail before, as I didn't realize the 25C didn't detect power loss and start up with "Pr Error" like other models. It makes sense that they didn't have room to add error detection though, since the 25 ROM was pretty much packed full right to the last byte. What differences are there in the 25C ROM? Just the omission of the startup sequence that zeros out the registers and fills program memory with GTO 00?

EDIT: I read the linked response from PANAMATIK, and that's basically the gist of it, but the ROM is identical, and HP instead changed the new CMOS memory chip to ignore the "clear all memory" instruction sent from the ACT. Clever.