HP 15c - Manual (Page 62)

62 Section 5: The Display and Continuous Memory
Low-Power Indication
When a flashing asterisk, which indicates
low battery power, appears in the lower
left-hand side of the display, there is no
reason to panic. You still have plenty of
calculator time remaining: at least 10
minutes if you continuously run programs,
and at least an hour if you do calculations
manually. Refer to appendix F (page 259)
for information on replacing the batteries.
Continuous Memory
Status
The Continuous Memory feature of the HP-15C retains the following in the
calculator, even when the display is turned off:

All numeric data stored in the calculator.

All programs stored in the calculator.

Position of the calculator in program memory.

Display mode and setting.

Trigonometric mode (Degrees, Radians, or Grads).

Any pending subroutine returns.

Flag settings (except flag 9, which clears when the display is
manually turned off).

User mode setting.

Complex mode setting.
When the HP-15C is turned on, it always ―wakes up‖ in Run mode. If the
calculator is turned off, Continuous Memory will be preserved for a short
period while the batteries are removed. Data and programs are preserved
longer than other aspects of calculator status. Refer to appendix F for
instructions on changing batteries.
0.0000
*