Subroutine Limits - HP -11C Owner's Handbook Manual

120 Section 8: Subroutines
Subroutine
Execution trans- (9](RTN] Execution trans-
fers to line 000 fers back to main
and halts. program; pending
return status
cleared.
As you can see, the only difference between using (go to
subroutine) and (go to branch) is the transfer of execution
after the [RTN].
After a [GTO], the next causes execution to transfer to
line 000 and halt; after a [GSB], the next causes
execution to transfer back to the main program and resume.
Subroutine Limits
A subroutine can call up another subroutine, and that subroutine
can call up yet another subroutine. This "subroutine nesting"' —the
execution of a subroutine within a subroutine—is limited only by
the number of returns ([RTN]) that can be held pending at any one
time in the HP-11C. Here is how the HP-11C operates with nested
subroutines.
Main Program
f (LBL)2
/ /
/ /
cse)3 |/
(G582
&
End