Clear Stack (CLST, CLSTK) and LastX

[PANAMATIK]

LastX is not part of the Stack. The Clear STK or CLST instruction of any RPN calculator should therefore never affect the LastX register.

HP-25, HP-33E HP-33C Clear STK keystroke doesn't affect LastX either in RUN or in PRGM Mode. Also HP42S as a reference is consistent and doesn't clear LastX in either mode. Other programmables of this series HP29C, HP34C and HP32S, 32Sii don't have a Clear STK or CLST instruction.

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.

Bernhard