HP 3000 Manuals

Using SNA IMF Pass Thru

For a Terminal 

If your HP terminal is emulating an IBM 3278 display station, you can
exit Pass Thru by pressing the f8 (EXIT) function key.  You cannot use
either BREAK or CTRL-Y to exit Pass Thru because both are disabled when
Pass Thru gains control of your terminal. 

MPE/iX 5.0 Documentation