HP 12C Financial calculator - Manual (Page 90)

90 Section 8: Programming Basics
File name: hp 12c_user's guide_English_HDPMBF12E44 Page: 90 of 209
Printered Date: 2005/7/29 Dimension: 14.8 cm x 21 cm
Example: Run the program created above to calculate the net cost of a typewriter
listing for $625 and an executive chair listing for $159.
Keystrokes Display
fs 155.00 Sets calculator to Run mode. Display
shows number previously calculated.
625 625. Keys in price of typewriter.
t 473.75 Net cost of typewriter.
159 159. Keys in list price of chair.
t 124.25 Net cost of chair.
That’s all there is to creating and running simple programs! But if you want to use
programs frequently, you’ll want to know more about programming — such as
how to check what keystrokes are stored in program memory, how many
keystrokes can be stored in program memory, how to correct or otherwise modify
programs, how to skip keystrokes when running a program, and so on. Before you
can understand these aspects of programming, we need to briefly discuss how
keystrokes are treated by the calculator when they are stored in Program mode
and when they are executed in Run mode.
Program Memory
Keystrokes entered into the calculator in Program mode are stored in program
memory. Each digit, decimal point, or function key is called an instruction and is
stored in one line of program memory — usually referred to simply as a program
line. Keystroke sequences beginning with the f, g, ?, :, and i prefix
keys are considered to comprise a complete instruction and are stored in only one
program line.
When a program is run, each instruction in program memory is executed — that is,
the keystroke in that program line is performed, just as if you were pressing the key
manually — beginning with the current line in program memory and proceeding
sequentially with the higher-numbered program lines.
Whenever the calculator is in Program mode (that is, whenever the PRGM status
indicator in the display is lit), the display shows information about the program line
to which the calculator is currently set. At the left of the display is the number of the
program line within program memory. The remaining digits in the display comprise
a code that indicates what instruction has been stored in that program line. No
code is shown for program line 00, since no regular instruction is stored there.