VMS V4.X Considerations

To run PortaCalc (AnalytiCalc) under VMS V4, you need to ensure the
terminal you're using is set to NOT have command line editing
during the run, so that arrow keys will go to the program rather
than being intercepted by the terminal driver. Just use the DCL
command to set terminal/noline to allow things to work correctly.
This is all the change that should be needed.