HP -33E Owner's Handbook Manual page 72

68 Subroutines
Subroutine Limits
A subroutine can call up another subroutine . and that subroutine can ca ll
up yet another. Subroutine branch ing is limited o nl y by the number of
relllrns
that can be held pending by the HP-33E. Three subro utine
returns can be he ld pend ing at anyone time in the HP-33 E. The diagram
below sho uld
make
this more clear.
Three
returns can be pending.
Main Program
line 00
l
.,
/
@!!) 09
I
r-----+---i ,
\
\
line 09
~ 17
/
,
@!J
line 17
/
t
JI
~25
/
~
\
\
\
@!J
line 25
@E)
The calcu lator can return back to the main progra m from subro utines
that are three deep , as shown. However. if you attempt to call up
subroutines that are four deep. the calc ulato r wi ll execute only three
returns:
Main
Program
line 00
I /
t
i
@!!)
09
I
Only three returns can be pending ...
line 09
~17
.,
~
;'
/
/
/
line 17
.,
@!!) 25
@!J
line 25
/
/
t
@]!I
33
\
~
~
... 50
execution will stop here.
/
/
I
,
\
line 33
ill[)