Section 6: Functions continue106
The HP-41C has five functions that are used to control the operating status of the calculator. The are ON , OFF , AON , AOFF , and PRGM . Notice that ON and PRGM cannot be recorded as instructions in a program. User mode is controlled either by the USER key or by a special USER mode flag. You will learn more about flags in section 14.
Power ON
When you press the ON key, it simply toggles the HP-41C power on and off. You may remember from section 1 that the HP-41C automatically turns itself off after 10 minutes of inactivity to conserve battery power. When you execute the ON function ( XEQ ALPHA ON ALPHA ), the turn-off feature is disabled and the HP-41C will no longer automatically turn itself off. The ON function stays in effect until you turn the HP-41C off.
Power OFF
When executed from the display or in a program, the OFF function simply turns the HP-41C power off.
PRGM , which toggles the HP-41C in and out of program mode, can only be executed by pressing the PRGM key on the HP-41C keyboard. Ther is no display execution form of PRGM . In addition, PRGM cannot be recorded as an instruction in a program.
The AON (ALPHA mode on) function places the HP-41C into ALPHA mode, and AOFF (ALPHA mode off) takes the HP-41C out of ALPHA mode. AON and AOFF are most useful in programs. In addition, notice that AON and AOFF perform the same function as the ALPHA key on the keyboard.