HP 49G Evanescent Flash Memory

[Gerald H]

Has anyone had some part of the operating system or stored programmes evaporate from memory?

What is a reasonable expectation of the half-life of flash memory in simply retaining data without being repeatedly re-flashed, particularly that used in the 49G?

[Steve Simpkin]

The industry standard for Flash memory data retention is over 100 years at 25C. That is a conservative figure so it is unlikely that is the cause of your issue. You could, of course, have a bad Flash memory device but I suspect it is more likely something bad occured in software.