Interactive Programs; Asking For Input - HP -28S Manual

27
Interactive Programs
Some programs require direction from the user-that is, from you
when you're running the program. When the user must supply values
for variables, a program can ask for input. When the user must
choose among several alternatives, a program can ask for a choice.
This chapter demonstrates how a program can ask for input or a
choice, using the following commands from the PROGRAM CON-
TROL menu.
Command Description
HALT Suspend program execution.
s WAIT Suspend program execution for s seconds.
KEY Return a key string if a key was pressed.
f
s BEEP Sound a tone of frequency
f
for s seconds.
CLLCD Clear the display.
n DISP Display an object in line n of the display.
CLMF Restore the normal display when the program completes
execution.
Asking for Input
The following sequence creates a custom input menu for variables A,
B, and
C
sounds a tone to alert the user, and halts for input.
... -: : STO ABC : : -
t'1HW
44~]
,1 BEEP HALT ...
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