DM-42 and WP-43S

[bhtooefr]

Aha - it'd require more code to leave the stack lift flag set if the enter is after an operation, instead of after digit entry - a test to see which happened - so that's why it always clears it. Fair enough.

In any case, it does feel logically inconsistent with the idea that Enter should duplicate whatever's in X, but there's an understandable technical reason for it on the older calcs. (That said, now I kinda want to see something that isn't trying to be implementation quirk-exact with HP calcs try stack lifting if Enter is used after an operation, but otherwise follow classic RPN behavior - I suspect that'd be faster to use than either classic RPN or Entry RPN/RPL.)