Where is NOP on the HP-67 ?

[[kby]]

I would ask why you want a NOP? The only reason the -65 has one is because the conditionals skip 2 steps, which in turn is because GOTO in particular is unmergef and takes two steps. Since all instructions on the -67/-97 are merged there is no “official” need for a NOP. Now there could be unofficial needs, such as timing loops and such, in which case, you should use the one that does what you want in terms of timing.

If the NOP was used in conjunction of a single-step or merged step as part of a conditional on the -65, then the code needs to be re-written to do it correctly.