HP 15C CE key bounce

[Steve Simpkin]

From my earlier post. There was some discussion on changing the keyboard debounce time in the firmware of the HP-15C CE to potentially help with this issue. While I do not know the results of this change, according to a Facebook Group post, it did appear to help in at least one case.

https://www.hpmuseum.org/forum/thread-19...#pid185697

Note a Programming cable for HP-15C CE calculator is required to make firmware changes. The firmware appears to be available, by request, from Divasson at The Calculator Store (https://www.hpmuseum.org/forum/user-1020.html). The firmware also fixes a DEC display issue with the alternate hidden HP-16C emulation mode in DEC display mode.

I would still recommend pursuing a warranty replacement for any unit that exhibits multiple entries with a keypress. The firmware change mentioned above *may* help units that can't be replaced under warranty.

Edit:
A new firmware and a memory backup/restore utility are now available for the HP-15C Collectors Edition.

Here is the official announcement.
https://www.hpmuseum.org/forum/thread-22078.html

The following HP Downloads page has a new firmware updated for the HP-15C Collector's Edition that increases the key debounce time. This may fix issues that some are having where pressing a key once registers multiple key presses.
https://hpcalcs.com/download/

Also on the same download page is a Windows utility program to backup and restore the memory of your HP-15C CE to a file. This is a huge new feature! See the following instructions PDF.
https://hpcalcs.com/downloads/apps/Instructions.pdf

Note the following USB Programming cable is required for either of these options.
https://www.thecalculatorstore.com/epage.../POGOcable