The standard Unix program tn3270 emulates an IBM 3270 terminal
and can be used to log onto VM and MVS systems that are
running TCP/IP. Since the two systems have such different assumptions
about terminal protocols, the emulation is not perfect and it may not
be adequate for heavy use. A map file is used to map the
keyboard you are using to the 3270 function keys. The default mapping
is for the pf keys to be mapped to the sequence escape
numerical key. Here is a list of the standard default keys. If you
use tn3270, you will want to set up your own map file so that
special function keys on your keyboard work with the 3270 emulation.