HP HP-67

158 Program Editing
When you added the B} instruction after step 007, program
memory was altered...
...from this... ...to this.
001 [ 001 G
002 [ 002 [}
003 B 003 [
004 004 03
005 0 005 O
006 006
007 [ 007 11
008 03 RTN 008 [ (5K - B instruction
009
X009
Q
FN
inserted
here.
010 (R/s \ 010
\ 011 (R/S
‘\_./>4 All subsequent
instructions are moved
557 T 221 down one step of
R/S R/S
922 \ 292 program memory.
223 x 223
224 (RS > 224 (R
\ R/S One instruction lost
here.
Stepping Backwards through a Program
The (back step) key allows you to back step through a loaded
program for editing whether the calculator is in RUN or W/PRGM
mode. When you press @} (BsT), the calculator backs up one step in
program memory. If the calculator is in RUN mode, the previous
step is displayed as long as you hold down the key. When you
release it, the original contents of the X-register are again displayed.
In W/PRGM mode, of course, you can see the step number and
keycode of the instruction in the display at all times. No instructions
are executed, whether you are in RUN or W/PRGM mode.