NorthStar 961 Reference Manual page 321

961/962 Operations and Reference Manual, Rev. A
6. Press the CURSOR PAD to highlight the desired chart,
then press the OPTION key to mark it "load" (the chart
won't actually be loaded until you first enter the chart
permit).
Instead of proceeding to mark the chart "load," the
ENTER NAVIGATOR PERMIT dialog box or the ENTER
SKIPPER PERMIT dialog box appears, and you're
prompted to manually enter a chart permit.
Chapter 13 - Customizing Setup Functions
Charts on disk screen
Page 13-51