HP 30B Annunciators, The Input Key, The Equals Key, Using the Input and Equals Keys

Annunciators

Annunciators are symbols that appear in the display as messages, or after certain keys or key combinations have been pressed. Annunciators are special symbols indicating a specific status in the calculator. Figure 3 illustrates the annunciator symbols in the display.

		Secondary		Valid item for the		Valid item for
	function active				Input key	the Equals key
									Low batteries
									Number recall
Assigned value									active
									RPN mode
									active
Begin mode			Radians active		360 day-count calendar active		Number storage
active								active

Figure 3 Annunciator Symbols in the Screen Display

The Input Key

The Ikey is used to input values for variables and execute menu items.

The Ikey is also used in Reverse Polish Notation (RPN) mode to enter a number on the stack or duplicate it.

The Equals Key

The =key is used at the end of a mathematical operation to calculate the final result. For example, 1+2=returns a final result of 3.

The =key, when pressed outside of a mathematical operation, also allows you to request a calculation for the value of an item. This request only applies to items that can be calculated.

Using the Input and Equals Keys

Suppose you wanted to calculate the effective interest rate for a 12% nominal interest rate with 12 payments per year in the Interest Conversion (IConv) menu. To open the IConv menu, press

:&. Nom %= displays on the top line, and the current value assigned to the nominal

6 Basic Features