You state that you are doing MVS console emulation. Do you mean 3270, or do
you really mean you are emulating an MVS system console? Normally PA1
retrieves the last console command issued. I do believe though that this is
customizable by the MVS sysprogs that setup your MVS system. PA1 by default
under PCOM is ALT-Insert.
The DUP key always puts a * in, even on a real 3270 terminal. I have no
idea what the DUP is used for, never have been able to figure it out. I
have been in the mainframe sysprog environment for 15+ years and most of it
has been SNA networking.