HP 49g Graphing Calculator - Manual (Page 191)

Algebraic and RPN modes
In RPN mode, the HP 49G makes extensive use of the stack. Wlien
developing programs in RPN mode, you use the stack to:
® provide the data that your program uses
e construct the commands that your program uses
® hold the output that your program generates.
In algebraic mode, the stack is not available. You use other methods to
build your program and to pass data to it.
Using Functions that require arguments
When using a function that requires arguments:
® In RPN mode, you place the arguments on the stack before calling the
fimction.
® In algebraic mode, you supply the arguments, enclosed in parentheses,
after the function call.
For example, you can use the INPUT command to prompt for data. The
following code segments demonstrate how to use the INPUT command to
collect data in both RPN and algebraic modes.
® In RPN mode, the following code segment prompts for input, collects
the data as a string and converts it to a nmnber. At the end of the
process, the data is on level 1 of the stack:
« "ENTER A NUMBER"
INPUT
OBJ —> »
® In Algebraic mode, the following code segment performs the same
operation. At the end of this process, the data is stored in a global
variable, NUMl, ready for use in the program.
Note that, since you are using a global rather than a local variable, you
can follow the variable declaration with a function.
« INPUT ("ENTER A NUMBER","
OBJ^ (NUMI) ^ NUMI »
¥
NUMI;
Introduction to programming Page 10-5