Which calculators had no known bugs?

[[kby]]

(08-05-2017 04:54 AM)Joe Horn Wrote:  At HHC 2010 (aka HHC MMX) I gave a brief talk about bug hunting and presented a short list of "My Favorite Bugs" in HP calculators. Please note that the list is by no means complete; it's just my favorites. Some are not really bugs, but hidden features or anomalies or simply unexpected weirdness.

I don’t consider the -65 items on your list to be bugs; rather, undocumented aspects or features (especially considering many steps useful). The deletion of the primary pointer while in a subroutine call crashing the calculator might be more of a bug.
Correction: for the last one, it’s not simply interrupting power that’s the trigger. You need to be recording a card (typically the default 5 program steps); the card will then have gaps which get misinterpreted when the card is read. This allows entering into program memory opcodes which don’t correspond to actual keystrokes, but are used by the internal logic. These include things like the primary and secondary pointers as well as the top of memory marker, there was a big article in 65 notes by Lou Cargil and one other person whose name escapes me right now that explained all of this.

Short power interruptions did cause some anomalous behavior on the -67, although I can’t remember what it was right now. That was also documented in a later issue of 65 Notes or the PPC Journal.