IBM HANDBOOK 260 - Manual (Page 258)

240 RS/6000 43P 7043 Models 150 and 260 Handbook
6. Perform maintenance work. Remember to set the $TERM variable so that
you can use full-screen editors, for example if you are using an ibm3151
ASCII terminal:
TERM=ibm3151
export TERM
7. Shut down and restart the system.
If problems persist, then you may require media to boot into Maintenance
mode, or you may have to restore the system.