Section 1: Getting Started16
When the HP-41C is in USER mode, all keys that have not been reassigned retain their normal mode functions. (‘‘Normal mode’’ means that the calculator is not in PRGM, ALPHA or USER mode.) Normal mode functions are the ones printed above and on the faces of the keys.
PRGM  Mode Key
When the calculator is in PRGM mode, keystrokes are recorded as program instructions. Programming and PRGM (mode) are covered in detail in part II of this handbook.
ALPHA  Mode Key
ALPHA mode is an exciting HP-41C feature that allows you to use both numbers and letters al well as several special characters. When you press ALPHA, the primary keyboard functions become the alphabetic characters printed in blue on the lower face of the keys. In addition, the ALPHA annunciator will turn on to show you that the calculator is in ALPHA mode. To take the HP-41C out of ALPHA mode, simply press ALPHA again.
Initial Display
Should you see MEMORY LOST in the display the first time you turn the HP-41C on, do not worry—it means that power to the continuous memory of the calculator has been interrupted at some time. Merely press    (the correction key) to clear the error, then continue. When power to continuous memory is interrupted, all information you placed into the HP-41C is lost.
Whenever the HP-41C is turned on, the display shows the number or ALPHA characters that were in the display before you turned the calculator off.
Display Capacity
The HP-41C display has 12 full character positions. You can put up to 24 characters in the display. As you place a string of ALPHA characters in the display that is larger than 11 characters the HP-41C automatically ‘‘scrolls’’ the characters off to the left (more about this later). For example, place the calculator into ALPHA mode, and press the following keys:
Keystrokes Display    
ALPHA      Places the HP-41C into ALPHA mode and turns the ALPHA display annunciator on.
ABCDEFGHIJK  ABCDEFGHIJK _   The display now contains 11 full characters.
L  BCDEFGHIJKL _   Now 12 characters.
M  CDEFGHIJKLM _   Now 13 characters.
ALPHA   0.0000   Takes the HP-41C out of ALPHA mode.