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13–4 Programming Techniques
In RPN mode,
 
Starts subroutine here.
 "!
Enters A.
 "!
Enters
B.
 "!
Enters C.
 "!
Enters D.
 
Recalls the data.
 
 
 
 º
A
2
.
 %
M
A
2
+ B
2
.
N
 %
O
A
2
+ B
2
+ C
2
P
 %
Q
A
2
+ B
2
+ C
2
+ D
2
R
 º
2222
DCBA +++
 !
Returns to main routine.
 
MOQ
Nested subroutine
 º65¸
 º
 -
Adds x
2
.
NPR
 !
Returns to subroutine S.
Branching (GTO)
As we have seen with subroutines, it is often desirable to transfer execution to a
part of the program other than the next line. This is called branching.
Unconditional branching uses the GTO (
go to) instruction to branch to a program
label. It is not possible to branch to a specific line number during a program.