Although you need to go out of your way to execute it, is this command as destructive as it sounds? I remember in the HP-65/67 days of HP that 'Clear: Program' in RUN mode just reset the program pointer to 00- and you had to be in PRGM mode for the command to erase all program lines. Likewise, in TI's days of the SR-52/56 and TI-58C/59, CP would actually erase program memory when in RUN mode and in Program mode CP would just clear the 't' register.

So, am I to understand that in RUN mode on the 33s or 35s, executing Clear: All actually wipes EVERYTHING, including all programs? Or, does this erase command take action if you're in PRGM mode, too? Is there a confirmation step to prevent you from accidentally carrying out Clear: All and erasing the whole memory contents?

Yes, in RUN mode it wipes everything including programs. In Program mode it wipes all programs (the mnemonic is changed to PGM).

That is why it is the only command in that menu to have a question to make sure you want to do it.

Very important to keep in mind!! Thanks! Good thing the confirmation is there. Keeps me from making a very regrettable mistake!