Every operation, command, and function on the HP-28S is available
on the keyboard or in a menu. When you select a menu, six
labels appear in the bottom line of the display. These labels constitute
which indicates the current definitions of the six
keys at the top of the keyboard. (The Cursor menu is an exception; its
definitions are printed in white above the menu keys.)
In addition to the keys that select specific menus (such as
I), the following keys control menu operations.
Cursor Menu On/Off.
When the Cursor menu is not ac-
tive: selects the Cursor menu. When the Cursor menu is
active: selects the previous menu .
Last Custom Menu.
Displays the Custom menu last
created by the MENU command.
Next Menu Row.
Displays the next row of menu labels.
If the last row is displayed, displays the first row .
Previous Menu Row.
Displays the previous row of
menu labels. If the first row is displayed, displays the
last row .
Turns Menu Lock on and off. When Menu
Lock is on, the shifted and unshifted npositions" are
switched for the top three rows of the lefthand key-
board (letter keys
through [K]). When Menu Lock is
selects the ARRAY menu and pressing
writes the letter A.