Clear Stack (CLST, CLSTK) and LastX

[MarkHaysHarris777]

(03-12-2015 02:19 PM)PANAMATIK Wrote:  IMO this is an inconsistency, which should be considered as a bug and should be included to the HP-35S bug list. The behaviour of any keystroke of a "keystroke programmable" calculator should be always the same in RUN and PRGM mode. The 35S is doing wrong in PRGM mode.

Not necessarily. Some commands are intended for interactive use and consideration; LASTX is one of those. The inconsistency is not whether the 35s clears LASTX in program mode, the inconsistency (quirk) is that it 'remembers' a LASTX in the first place, in program mode. LASTX is intended for interactive error correction by being able to recover the X register that existed 'before' the last operation 'destroyed' it. This is not necessary, nor desirable, in program mode. If there is to be a LASTX all at, for program mode, it should be the LASTX 'before' the program ran-- not the LASTX of the last operation within the program!

PS This is the 'only' glitch I find -at all- while playing with the WP34s... it needs a real LASTX (I don't really like the L register thing its doing).

Cheers,
marcus