HP -67 Owner's Handbook Manual page 204

200 Subroutines
oo1 [ o
002 Gl
o3 O
004 [ 8
005 B2
006 0O o6 @ 08
o7z @ /1 o2 [ma
gzg ° 3 // / 028 [
RTN
w GGo
011 g ~————~ |/
- — / 031 1
012 N 032 [FN3
013 [EE1 \ 03: 8
014 2 I 034 4
015 @ I\
I\ 035
o168 / \ 036 B
o7 @ / N7 @
018 o 2 _// e 038 [ RN
019 [ G598 ::______,'"
020 &
021 @91
022 2
023
024 B
025 0
With the modified program, when you press [}, execution begins with
the 3} instruction in step 010. When the 8 instruction in
step 011 is encountered, execution transfers to 8 in step 026 and
computes the quantities —b and Vb? — 4ac, placing them in the X-
and Y-registers of the stack, ready for addition or subtraction. When
the instruction in step 038 is encountered, execution transfers
back to the main routine and continues with the instruction in step
012. Thus the root r, is computed and displayed, and the routine stops
with the in step 017.