Free42 OVER stack operation

[Thomas Klemm]

Here are some others:

SWAP:  X<>Y
DUP:   RCL ST X | ENTER
DROP:  R↓ | CLX  +
OVER:  RCL ST Y
ROT:   X<>Y  X<> ST Z
UNROT: X<> ST Z  X<>Y
NIP:   X<>Y  R↓
TUCK:  X<>Y  RCL ST Y
2DUP:  RCL ST Y  RCL ST Y
2DROP: R↓  R↓
2SWAP: R↓  R↓

Not all of them do exactly what they do on the HP-50g.
I couldn't come up with a simple DROP that saves X in LASTX and duplicates T.
But often that is not needed.