HP -67 Owner's Handbook Manual page 203

Subroutines 199
Here is a complete program for calculating the two roots of a quad-
ratic equation:
Input a Input b Input ¢
001 M([ED@ 004 WMEIE@ 007 D([ED@E
002 1 005 2 008 3
003 0 006 0 009 0O
Calculate r, Calculate ry
010 o 028 [ a8
011 2 029 2
012 CHS 030 CHS
013 2 031 2
014 B ) , 032 B
015 1 I:'zf:gf:r':"'"s 033 1
016 3 memory are 034 3
017 8 identical. 035
018 4 036 4
019 037
020 B 038 &
021 039
022 090 B
023 1 041 1
024 2 042 2
025 043
026 B 44 B
027 045 0
Since the routine for calculating r, contains a large section of program
memory that is identical to a large section in the routine for calculating
Iz, you can simply create a subroutine that will execute this section of
Instructions. The subroutine is then called up and executed in both the
solution for r, and the solution for r,: