HP HP-11C

Section 8: Subroutines 125
For additional guidelines concerning the use of subroutines, refer
to page 210, Subroutines, in part III of this handbook.
Notice that and instructions always cause the
calculator to search downward in program memory for the
specified label. This feature often allows you to write a program in
such a way that it uses a given label more than once.
Example: The following program to calculate the value of the
expression \/x? + y2 + 22 + t2 uses to identify both the
beginning of the program and a subroutine within the program.
The program is executed by placing the variables x, y, 2, and ¢ in
the stack and pressing [A].*
Keystrokes Display
000-
(f)JCLEAR 000-
AE0GE] 001-42,21,11
002- 4311 x2
003- 3211 Calculates y?and x2 + y?
004- 3211 Calculatesz?and x2 + y2
+2z2
005- 3211 CalculatestZandx2+y2+
2, 42
2+t
006- 11 Calculates \/x2 + y2 + 22 + 2
007- 4332
008-42,21,11
009- 34
010- 4311
011- 40
012- 43 32
*While it is generally best to avoid the use of identical labels to reduce the possibility of
confusion or programming errors, the following program illustrates one way identical
labels might be used, if necessary.