Indirect Line Number Branches And Subroutines - HP -11C Owner's Handbook Manual

Section 9: The Index Register 137/138
Indirect Line Number Branches and Subroutines
Program line numbers can be indirectly addressed by a branch or
subroutine instruction in almost the same way that labels are
indirectly addressed. As covered earlier, when an indirect branch
or subroutine instruction is executed with a positive nnnnn value
in Ry, execution transfers to the label addressed by nnnnn and
resumes. However, when an indirect branch or subroutine
instruction is executed with a negative nnnnn value in Rj,
execution transfers to the line number addressed by the absolute
value of =nnnnn.
If: ...then...
R, 1-7.00900 001 - Instruction
002- Instruction
003-[GT0](1] -
004- Instruction } Execution
nnnnn
Xxx
Yy
005- Instruction
| t}'ansfers to
(default
.
line 007 and
t0 01)
006- Instruction
| resumes.
007- [f]{LBL]3 -
008- Instruction
008- Instruction